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Monday, April 12, 2021

Public opinion on climate change

From Wikipedia, the free encyclopedia
 
Placard warning "1 °C and rising..." at an Extinction Rebellion protest (London, 2019).

Public opinion on climate change is the aggregate of attitudes or beliefs held by the adult population concerning the science, economics, and politics of climate change. It is affected by media coverage of climate change.

General overview

In January 2021, the United Nations Development Programme reported results of the largest-ever climate survey, which indicated that two-thirds of respondents consider climate change as an emergency, with forest and land conservation being the most popular solutions. Specifically, The Peoples' Climate Vote (1.2 million respondents in over 50 countries) found that 64% said climate change was an emergency – presenting a clear and convincing call for decision-makers to step up on ambition.

Influences on individual opinion

Geographic region

For a list of countries and their opinion see "Climate change opinion by country" below

United States, Europe, and Australia are the darkest while Africa, the Middle East, and Oceania are the lightest.
Proportion reporting knowing "something" or "a great deal" about global warming in 2007–08. Darker areas indicate a greater proportion of individuals aware, yellow indicates no data.
 
Latin America and Japan are the darkest while the remainder are either much lighter or mixed.
Proportion responding yes when asked, "Temperature rise is part of global warming or climate change. Do you think rising temperatures are [...] a result of human activities?"
 
The Americas, Europe, Australia, Kenya, and Japan are the darkest. The remainder is much lighter.
Proportion responding that global warming is a serious personal threat

Between 2007–20010, the Gallup World Poll surveyed individuals in 143 countries. This poll queried whether the respondent knew of global warming. Those who had a basic concept of global warming didn't necessarily connect it to human activities, revealing that knowledge of global warming and the knowledge that it's human-induced are two separate things. Over a third of the world's population were unaware of global warming. Developing countries have less awareness than developed, and Africa the least aware. Of those aware, residents of Latin America and developed countries in Asia led the belief that climate change is a result of human activities while Africa, parts of Asia and the Middle East, and a few countries from the former Soviet Union led in the opposite. Opinion within the United Kingdom was divided.

The first major worldwide poll, conducted by Gallup in 2008–2009 in 127 countries, found that some 62% of people worldwide said they knew about global warming. In the industrialized countries of North America, Europe, and Japan, 67% or more knew about it (97% in the U.S., 99% in Japan); in developing countries, especially in Africa, fewer than a quarter knew about it, although many had noticed local weather changes. The survey results suggest that between 2007 and 2010 only 42% of the world's population were aware of climate change and believed that it is caused by human activity. Among those who knew about global warming, there was a wide variation between nations in belief that the warming was a result of human activities.

Adults in Asia, with the exception of those in developed countries, are the least likely to perceive global warming as a threat. In developed Asian countries like South Korea, perceptions of climate change are associated with strong emotional beliefs about its causes. In the western world, individuals are the most likely to be aware and perceive it as a very or somewhat serious threat to themselves and their families; although Europeans are more concerned about climate change than those in the United States. However, the public in Africa, where individuals are the most vulnerable to global warming while producing the least carbon dioxide, is the least aware – which translates into a low perception that it is a threat.

These variations pose a challenge to policymakers, as different countries travel down different paths, making an agreement over an appropriate response difficult. While Africa may be the most vulnerable and produce the least amount of greenhouse gases, they are the most ambivalent. The top five emitters (China, the United States, India, Russia, and Japan), who together emit half the world's greenhouse gases, vary in both awareness and concern. The United States, Russia, and Japan are the most aware at over 85% of the population. Conversely, only two-thirds of people in China and one-third in India are aware. Japan expresses the greatest concern, which translates into support for environmental policies. People in China, Russia, and the United States, while varying in awareness, have expressed a similar proportion of aware individuals concerned. Similarly, those aware in India are likely to be concerned, but India faces challenges spreading this concern to the remaining population as its energy needs increase over the next decade.

An online survey on environmental questions conducted in 20 countries by Ipsos MORI, "Global Trends 2014", shows broad agreement, especially on climate change and if it is caused by humans, though the U.S. ranked lowest with 54% agreement. It has been suggested that the low U.S. ranking is tied to denial campaigns.

A 2010 survey of 14 industrialized countries found that skepticism about the danger of global warming was highest in Australia, Norway, New Zealand and the United States, in that order, correlating positively with per capita emissions of carbon dioxide.

Education

In countries varying in awareness, an educational gap translates into a gap in awareness. However an increase in awareness does not always result in an increase in perceived threat. In China, 98% of those who have completed four years or more of college education reported knowing something or a great deal of climate change while only 63% of those who have completed nine years of education reported the same. Despite the differences in awareness in China, all groups perceive a low level of threat from global warming. In India, those who are educated are more likely to be aware, and those who are educated there are far more likely to report perceiving global warming as a threat than those who are not educated. In Europe, individuals who have attained a higher level of education perceive climate change as a serious threat. There is also a strong association between education and Internet use. Europeans who use the Internet more are more likely to perceive climate change as a serious threat. However, a survey of American adults found "little disagreement among culturally diverse citizens on what science knows about climate change. In the US, individuals with greater science literacy and education have more polarized beliefs on climate change.

Demographics

Residential demographics affect perceptions of global warming. In China, 77% of those who live in urban areas are aware of global warming compared to 52% in rural areas. This trend is mirrored in India with 49% to 29% awareness, respectively.

Of the countries where at least half the population is aware of global warming, those with the majority who believe that global warming is due to human activities have a greater national GDP per unit energy—or, a greater energy efficiency.

In Europe, individuals under fifty-five are more likely to perceive both "poverty, lack of food and drinking water" and climate change as a serious threat than individuals over fifty-five. Male individuals are more likely to perceive climate change as a threat than female individuals. Managers, white-collar workers, and students are more likely to perceive climate change as a greater threat than house persons and retired individuals.

In the United States, conservative white men are more likely than other Americans to deny climate change. A very similar trend has been documented in Norway, where 63% of conservative men deny anthropogenic climate change compared to just 36% of the general Norwegian population. In Sweden, political conservatism was similarly found to correlate with climate change denial, while in Brazil, climate change denial has been found to be more correlated with gender, with men being significantly more likely to express denialist viewpoints compared to women.

In Great Britain, a movement of by women known as "birthstrikers" advocates for refraining from procreation until the possibility of "climate breakdown and civilisation collapse" is averted.

In general, there is a substantial variation in the direction in which demographic traits, like age or gender, correlate with climate change concern. While women and younger people tend to be more concerned about climate change in English-speaking constituencies, the opposite is true in most African countries.

Political identification

Democrats (blue) and Republicans (red) have long differed in views of the importance of addressing climate change, with the gap widening in the late 2010s mainly through Democrats' share increasing by more than 30 points.
(Discontinuity resulted from survey changing in 2015 from reciting "global warming" to "climate change".)

In the United States, support for environmental protection was relatively non-partisan in the twentieth century. Republican Theodore Roosevelt established national parks whereas Democrat Franklin Delano Roosevelt established the Soil Conservation Service. Republican Richard Nixon was instrumental in founding the United States Environmental Protection Agency, and tried to install a third pillar of NATO dealing with environmental challenges such as acid rain and the greenhouse effect. Daniel Patrick Moynihan was Nixon's NATO delegate for the topic.

This non-partisanship began to erode during the 1980s, when the Reagan administration described environmental protection as an economic burden. Views over global warming began to seriously diverge between Democrats and Republicans during the negotiations that led up to the creation of the Kyoto Protocol in 1998. In a 2008 Gallup poll of the American public, 76% of Democrats and only 41% of Republicans said that they believed global warming was already happening. The opinions of the political elites, such as members of Congress, tends to be even more polarized.

Public opinion on climate change can be influenced by who people vote for. Although media coverage influences how some view climate change, research shows that voting behavior influences climate change skepticism. This shows that people's views on climate change tend to align with the people they voted for.

In Europe, opinion is not strongly divided among left and right parties. Although European political parties on the left, including Green parties, strongly support measures to address climate change, conservative European political parties maintain similar sentiments, most notably in Western and Northern Europe. For example, Margaret Thatcher, never a friend of the coal mining industry, was a strong supporter of an active climate protection policy and was instrumental in founding the Intergovernmental Panel on Climate Change and the British Hadley Centre for Climate Prediction and Research. Some speeches, as to the Royal Society on 27 September 1988 and to the UN general assembly in November 1989 helped to put climate change, acid rain, and general pollution in the British mainstream. After her career, however, Thatcher was less of a climate activist, as she called climate action a "marvelous excuse for supranational socialism", and called Al Gore an "apocalyptic hyperbole". France's center-right President Chirac pushed key environmental and climate change policies in France in 2005–2007. Conservative German administrations (under the Christian Democratic Union and Christian Social Union) in the past two decades have supported European Union climate change initiatives; concern about forest dieback and acid rain regulation were initiated under Kohl's archconservative minister of the interior Friedrich Zimmermann. In the period after former President George W. Bush announced that the United States was leaving the Kyoto Treaty, European media and newspapers on both the left and right criticized the move. The conservative Spanish La Razón, the Irish Times, the Irish Independent, the Danish Berlingske Tidende, and the Greek Kathimerini all condemned the Bush administration's decision, as did left-leaning newspapers.

In Norway, a 2013 poll conducted by TNS Gallup found that 92% of those who vote for the Socialist Left Party and 89% of those who vote for the Liberal Party believe that global warming is caused by humans, while the percentage who held this belief is 60% among voters for the Conservative Party and 41% among voters for the Progress Party.

The shared sentiments between the political left and right on climate change further illustrate the divide in perception between the United States and Europe on climate change. As an example, conservative German Prime Ministers Helmut Kohl and Angela Merkel have differed with other parties in Germany only on how to meet emissions reduction targets, not whether or not to establish or fulfill them.

A 2017 study found that those who changed their opinion on climate change between 2010 and 2014 did so "primarily to align better with those who shared their party identification and political ideology. This conforms with the theory of motivated reasoning: Evidence consistent with prior beliefs is viewed as strong and, on politically salient issues, people strive to bring their opinions into conformance with those who share their political identity". Furthermore, a 2019 study examining the growing skepticism of climate change among American Republicans argues that persuasion and rhetoric from party elites play a critical role in public opinion formation, and that these elite cues are propagated through mainstream and social media sources.

For those who care about the environment and want change are not happy about some policies, for example the support of the cap and trade policy but very few people are willing to pay more than 15 dollars per month for a program that is supposed to help the environment. There is evidence that not many people are aware of climate change in the US, only 2% of respondents ranked the environment as the top issue in the US.

Individual risk assessment and assignment

The IPCC attempts to orchestrate global (climate) change research to shape a worldwide consensus. However, the consensus approach has been dubbed more a liability than an asset in comparison to other environmental challenges. The linear model of policy-making, based on a more knowledge we have, the better the political response will be is said to have not been working and is in the meantime rejected by sociology.

Sheldon Ungar, a Canadian sociologist, compares the different public reactions towards ozone depletion and climate change. The public opinion failed to tie climate change to concrete events which could be used as a threshold or beacon to signify immediate danger. Scientific predictions of a temperature rise of two to three degrees Celsius over several decades do not respond with people, e.g. in North America, that experience similar swings during a single day. As scientists define global warming a problem of the future, a liability in "attention economy", pessimistic outlooks in general and assigning extreme weather to climate change have often been discredited or ridiculed (compare Gore effect) in the public arena. While the greenhouse effect per se is essential for life on earth, the case was quite different with the ozone shield and other metaphors about the ozone depletion. The scientific assessment of the ozone problem also had large uncertainties. But the metaphors used in the discussion (ozone shield, ozone hole) reflected better with lay people and their concerns.

The idea of rays penetrating a damaged "shield" meshes nicely with abiding and resonant cultural motifs, including "Hollywood affinities". These range from the shields on the Starship Enterprise to Star Wars, ... It is these pre-scientific bridging metaphors built around the penetration of a deteriorating shield that render the ozone problem relatively simple. That the ozone threat can be linked with Darth Vader means that it is encompassed in common sense understandings that are deeply ingrained and widely shared. (Sheldon Ungar 2000)

The chlorofluorocarbon (CFC) regulation attempts of the end of the 1980s profited from those easy-to-grasp metaphors and the personal risk assumptions taken from them. As well the fate of celebrities like President Ronald Reagan, which had skin cancer removal in 1985 and 1987, was of high importance. In case of the public opinion on climate change, no imminent danger is perceived.

Ideology

In the United States, ideology is an effective predictor of party identification, where conservatives are more prevalent among Republicans, and moderates and liberals among independents and Democrats. A shift in ideology is often associated with in a shift in political views. For example, when the number of conservatives rose from 2008 to 2009, the number of individuals who felt that global warming was being exaggerated in the media also rose. The 2006 BBC World Service poll found that when asked about various policy options to reduce greenhouse gas emissions – tax incentives for alternative energy research and development, installment of taxes to encourage energy conservation, and reliance on nuclear energy to reduce fossil fuels. The majority of those asked felt that tax incentives were the path of action that they preferred.

As of May 2016, polls have repeatedly found that a majority of Republican voters, particularly young ones, believe the government should take action to reduce carbon dioxide emissions.

The pursuit of green energy is an ideology that defines hydroelectric dams, natural gas power plants, and nuclear power as unacceptable alternative energies for the eight billion tons of coal burnt each year. While there is popular support for wind, solar, biomass, and geothermal energy, all these sources combined only supplied 1.3% of global energy in 2013.

After a country host the annual Conference of the Parties (COP) climate legislation increases which causes policy diffusion. There is strong evidence of policy diffusion which is when a policy is made it is influenced by the policy choices made elsewhere.This can a have positive effect on climate legislation.

Scientific analyses of international survey data show that right-wing orientation and individualism are strongly correlated to climate change denial in the US and other English-speaking countries, but much less in most non-English speaking nations.

Charts

A 2018 study found that individuals were more likely to accept that global temperatures were increasing if they were shown the information in a chart rather than in text.

Issues

Science

A scientific consensus on climate change exists, as recognized by national academies of science and other authoritative bodies. The opinion gap between scientists and the public in 2009 stands at 84% to 49% that global temperatures are increasing because of human-activity. However, more recent research has identified substantial geographical variation in the public's understanding of the scientific consensus.

Economics

Economic debates weigh the benefits of limiting industrial emissions of mitigating global warming against the costs that such changes would entail. While there is a greater amount of agreement over whether global warming exists, there is less agreement over the appropriate response. Electric or petroleum distribution may be government owned or utilities may be regulated by government. The government owned or regulated utilities may, or may not choose to make lower emissions a priority over economics, in unregulated counties industry follows economic priorities. An example of the economic priority is Royal Dutch Shell PLC reporting CO2 emissions of 81 million metric tonnes in 2013.

Media

The popular media in the U.S. gives greater attention to skeptics relative to the scientific community as a whole, and the level of agreement within the scientific community has not been accurately communicated. US popular media coverage differs from that presented in other countries, where reporting is more consistent with the scientific literature. Some journalists attribute the difference to climate change denial being propagated, mainly in the US, by business-centered organizations employing tactics worked out previously by the US tobacco lobby. However, one study suggests that these tactic are less prominent in the media and that the public instead draws their opinions on climate mainly from the cues of political party elites.

The efforts of Al Gore and other environmental campaigns have focused on the effects of global warming and have managed to increase awareness and concern, but despite these efforts as of 2007, the number of Americans believing humans are the cause of global warming was holding steady at 61%, and those believing the popular media was understating the issue remained about 35%. Between 2010 and 2013, the number of Americans who believe the media under-reports the seriousness of global warming has been increasing, and the number who think media over-states it has been falling. According to a 2013 Gallup US opinion poll, 57% believe global warming is at least as bad as portrayed in the media (with 33% thinking media has downplayed global warming and 24% saying coverage is accurate). Less than half of Americans (41%) think the problem is not as bad as media portrays it.

September 2011 Angus Reid Public Opinion poll found that Britons (43%) are less likely than Americans (49%) or Canadians (52%) to say that "global warming is a fact and is mostly caused by emissions from vehicles and industrial facilities". The same poll found that 20% of Americans, 20% of Britons and 14% of Canadians think "global warming is a theory that has not yet been proven".

A March 2013 Public Policy Polling poll about widespread and infamous conspiracy theories found that 37% of American voters believe that global warming is a hoax, while 51% do not.

A 2013 poll in Norway conducted by TNS Gallup found that 66% of the population believe that climate change is caused by humans, while 17% do not believe this.

Politics

September 2019 climate strike in Sydney, Australia

Public opinion impacts on the issue of climate change because governments need willing electorates and citizens in order to implement policies that address climate change. Further, when climate change perceptions differ between the populace and governments, the communication of risk to the public becomes problematic. Finally, a public that is not aware of the issues surrounding climate change may resist or oppose climate change policies, which is of considerable importance to politicians and state leaders.

Public support for action to forestall global warming is as strong as public support has been historically for many other government actions; however, it is not "intense" in the sense that it overrides other priorities.

A 2009 Eurobarometer survey found that, on the average, Europeans rate climate change as the second most serious problem facing the world today, between "poverty, the lack of food and drinking water" and "a major global economic downturn." 87% of Europeans consider climate change to be a "serious" or "very serious" problem, while 10% "do not consider it a serious problem." However, the proportion who believe it to be a problem has dropped in the period 2008/9 when the surveys were conducted. While the small majority believe climate change is a serious threat, 55% percent believe the EU is doing too little and 30% believe the EU is going the right amount. As a result of European Union climate change perceptions, "climate change is an issue that has reached such a level of social and political acceptability across the EU that it enables (indeed, forces) the EU Commission and national leaders to produce all sorts of measures, including taxes." Despite the persistent high level of personal involvement of European citizens, found in another Eurobarometer survey in 2011, EU leaders have begun to downscale climate policy issues on the political agenda since the beginning of the Eurozone crisis.

Although public opinion may not be the only factor influencing renewable energy policies, it is a key catalyst. Research has found that the shifts in public opinion in the direction of pro-environmentalism strongly increased the adoption of renewable energy policies in Europe, which can thus be applied in the U.S. and how important climate solutions are to Americans. Moreover, other research shows that countries in which more people believe in human-made climate change tend to have higher carbon prices.

The proportion of Americans who believe that the effects of global warming have begun or will begin in a few years rose to a peak in 2008 where it then declined, and a similar trend was found regarding the belief that global warming is a threat to their lifestyle within their lifetime. Concern over global warming often corresponds with economic downturns and national crisis such as 9/11 as Americans prioritize the economy and national security over environmental concerns. However the drop in concern in 2008 is unique compared to other environmental issues. Considered in the context of environmental issues, Americans consider global warming as a less critical concern than the pollution of rivers, lakes, and drinking water; toxic waste; fresh water needs; air pollution; damage to the ozone layer; and the loss of tropical rain forests. However, Americans prioritize global warming over species extinction and acid rain issues. Since 2000 the partisan gap has grown as Republican and Democratic views diverge.

Climate change opinion by country

United States, Europe, and Australia are the darkest while Africa, the Middle East, and Oceania are the lightest.
Proportion who reported knowing "something" or a "great deal" about global warming. Darker areas indicate a greater proportion of individuals aware, yellow indicates no data.
 
Latin America and Japan are the darkest while the remainder are either much lighter or mixed.
Proportion responding yes when asked, "Temperature rise is part of global warming or climate change. Do you think rising temperatures are [...] a result of human activities?"
 
The Americas, Europe, Australia, Kenya and Japan are the darkest. The remainder much lighter.
Proportion responding in 2008–09 that global warming was a serious personal threat.

Climate change opinion is the aggregate of public opinion held by the adult population. Cost constraints often restrict surveys to sample only one or two countries from each continent or focus on only one region. Because of differences among questions, wording, and methods—it is difficult to reliably compare results or to generalize them to opinions held worldwide.

In 2007–2008, the Gallup Poll surveyed individuals from 128 countries in the first comprehensive study of global opinions. The Gallup Organization aggregated opinion from the adult population fifteen years of age and older, either through the telephone or personal interviews, and in both rural and urban areas except in areas where the safety of interviewer was threatened and in scarcely populated islands. Personal interviews were stratified by population size or geography and cluster sampling was achieved through one or more stages. Although error bounds vary, they were all below ±6% with 95% confidence.

Weighting countries to a 2008 World Bank population estimate, 61% of individuals worldwide were aware of global warming, developed countries more aware than developing, with Africa the least aware. The median of people perceiving it as a threat was 47%. Latin America and developed countries in Asia led the belief that climate change was a result of human activities, while Africa, parts of Asia and the Middle East, and countries from the Former Soviet Union led in the opposite. Awareness often translates to concern, although of those aware, individuals in Europe and developed countries in Asia perceived global warming as a greater threat than others.

Views on climate change by region

Africa

People in Africa are relatively concerned about climate change compared to the Middle East and parts of Asia. However, they are less concerned than most of Latin America and Europe. Currently, 61% of people in Africa consider climate change to be a very serious problem, and 52% believe that climate change is harming people now. While 59% of Africans are worried about droughts or water shortages, only 16% are concerned about severe weather, and 3% are concerned about rising sea levels. Countries in Sub-Saharan Africa are especially troubled about increasing desertification even as they account for .04% of global carbon dioxide emissions. In Sub-Saharan Africa, the concern over climate change drops to only 34% of the population considering climate change to be a "very" or "somewhat serious issue". Even so, according to the Pew Research Center 2015 Global Attitudes Survey, some particular countries are more concerned than others. In Uganda 79% of people, 68% in Ghana, 45% in South Africa and 40% in Ethiopia consider climate change to be a very serious problem.

Latin America

Latin America has a larger percentage of people concerned with climate change than other regions of the world. 74% consider climate change to be a serious problem and 77% say that it is harming people now which is 20 points higher than the global median according to the Pew Research Center. 63% of people in Latin America are very concerned that climate change will harm them personally. When looked at more specifically, Mexico and Central America are the most worried at 81.5% believing that climate change is a very serious issue. South America is slightly less anxious at 75% and the Caribbean, at the relatively high rate of 66.7%, is the least concerned. Brazil is an important country in global climate change politics because it is the eleventh largest emitter and unlike other large emitter countries, 86% consider global warming to be a very serious problem. Compared to the rest of the world, Latin America is more consistently concerned with high percentages of the population worried about climate change. Further, in Latin America, 67% believe in personal responsibility for climate change and say that people will have to make major lifestyle modifications.

Europe

Europeans have a tendency to be more concerned about climate change than much of the world, with the exception of Latin America. However there is a divide between Eastern Europe, where people are less worried about climate change, and Western Europe. A global climate survey by the European Investment Bank showed that climate is the number one concern for Europeans. Most respondents said they were already feeling the effects of climate change. Many people believed climate change can still be reversed with 68% of Spanish respondents believing it can be reversed and 80% seeing themselves as part of the solution.

In Europe, there is a range from 88% to 97% of people feeling that climate change is happening and similar ranges are present for agreeing that climate change is caused by human activity and that the impacts of it will be bad. Generally Eastern European countries are slightly less likely to believe in climate change, or the dangers of it, with 63% saying it is very serious, 24% considering it to be fairly serious and only 10% saying it is not a serious problem. When asked if they feel a personal responsibility to help reduce climate change, on a scale of 0, not at all, to 10, a great deal, Europeans respond with the average score of 5.6. When looked at more specifically, Western Europeans are closer to the response of 7 while Eastern European countries respond with an average of less than 4. When asked if Europeans are willing to pay more for climate change, 49% are willing, however only 9% of Europeans have already switched to a greener energy supply. While a large majority of Europeans believe in the dangers of climate change, their feelings of personal responsibility to deal with the issue are much more limited. Especially in terms of actions that could already have been taken - such as having already switched to greener energies discussed above - one can see Europeans' feelings of personal responsibility are limited. 90% of Europeans interviewed for the European Investment Bank Climate Survey 2019 believe their children will be impacted by climate change in their everyday lives and 70% are willing to pay an extra tax to fight climate change.

Asia/Pacific

Asia and the Pacific have a tendency to be less concerned about climate change, except small island states, with developing countries in Asia being less concerned than developed countries. In Asia and the Pacific, around 45% of people believe that climate change is a very serious problem and similarly 48% believe that it is harming people now. Only 37% of people in Asia and the Pacific are very concerned that climate change will harm them personally. There is a large gap between developing Asia and developed Asia. Only 31% of developing Asia considers global warming to be a "very" or "somewhat" serious threat and 74% of developed Asia considers global warming to be a serious threat. It could be argued that one reason for this is that people in more developed countries in Asia are more educated on the issues, especially given that developing countries in Asia do face significant threats from climate change. The most relevant views on climate change are those of the citizens in the countries that are emitting the most. For example, in China, the world's largest emitter, 68% of Chinese people are satisfied with their government's efforts to preserve the environment. And in India, the world's third largest emitter, 77% of Indian people are satisfied with their country's efforts to preserve the environment. 80% of Chinese citizens interviewed in the European Investment Bank Climate Survey 2019 believe climate change is still reversible, 72% believe their individual behaviour can make a difference in addressing climate change.

Middle East

While the increasing severity of droughts and other dangerous realities are and will continue to be a problem in the Middle East, the region has one of the smallest rates of concern in the world. 38% believe that climate change is a very serious problem and 26% believe that climate change is harming people now. Of the four Middle Eastern countries polled in a Pew Global Study, on what is their primary concern, Israel, Jordan, and Lebanon named ISIS, and Turkey stated United States encroachment. 38% of Israel considers climate change to be a major threat to their country, 40% of Jordan, 58% of Lebanon and 53% of Turkey. This is compared to relatively high numbers of residents who believe that ISIS is a major threat to their country ranging from 63% to 97%. In the poll, 38% of the Middle East are concerned about drought and 19% are concerned about long periods of unusually hot weather. 42% are satisfied with their own country's current efforts to preserve the environment.

North America

U.S. Democrats (blue) and Republicans (red) have long differed in views of the importance of addressing climate change, with the gap widening in the late 2010s mainly through Democrats' share increasing by more than 30 points.
(Discontinuity resulted from survey changing in 2015 from reciting "global warming" to "climate change".)

North America has mixed perceptions on climate change ranging from Mexico and Canada that are both more concerned, and the United States, the world's second largest emitter, that is less concerned. Mexico is the most concerned about climate change of the three countries in North America. 90% consider climate change to be a very serious problem and 83% believe that climate change is harming people substantially right now. Canadians are also seriously concerned, 20% are extremely concerned, 30% are definitely concerned, 31% are somewhat concerned and only 19% are not very/not at all concerned about climate change. While the United States which is the largest emitter of CO2 in North America and the second largest emitter of CO2 in the world has the lowest degrees of concern about climate change in North America. While 61% of Americans say they are concerned about climate change, that is 30% lower than Mexico and 20% lower than Canada. 41% believe that climate change could impact them personally. Nonetheless, 70% of Americans believe that environmental protections are more important than economic growth according to a Yale climate opinion study. 76% of US citizens interviewed for the European Investment Bank Climate Survey 2019 believe developed countries have a responsibility to help developing countries address climate change.

United States

In 2009 Yale University conducted a study identifying global warming's "Six Americas". The report identifies six audiences with different opinions about global warming: The alarmed (18%), the concerned (33%), the cautious (19%), the disengaged (12%), the doubtful (11%) and the dismissive (7%). The alarmed and concerned make out the largest percentage and think something should be done about global warming. The cautious, disengaged and doubtful are less likely to take action. The dismissive are convinced global warming is not happening. These audiences can be used to define the best approaches for environmental action. The theory of the 'Six Americas' is also used for marketing purposes.

Opinions in the United States vary intensely enough to be considered a culture war.

In a January 2013 survey, Pew found that 69% of Americans say there is solid evidence that the Earth's average temperature has gotten warmer over the past few decades, up six points since November 2011 and 12 points since 2009.

A Gallup poll in 2014 concluded that 51 percent of Americans were a little or not at all worried about climate change, 24 percent a great deal and 25 percent a fair amount.

In 2015, 32 percent or Americans were worried about global warming as a great deal, 37 percent in 2016, and 45 percent in 2017. A poll taken in 2016 shows that 52% of Americans believe climate change to be caused by human activity, while 34% state it is caused by natural changes. Data is increasingly showing that 62 percent of Americans believe that the effects of global warming are happening now in 2017.

In 2016 GALLUP found that 64% of Americans are worried about global warming, 59% believed that global warming is already happening and 65% is convinced that global warming is caused by human activities. These numbers show that awareness of global warming is increasing in the United States

In 2019 GALLUP found that one-third of Americans blame unusual winter temperatures on climate change.

In 2019 the Yale Program on Climate Change Communication found that 69% of Americans believe that climate change is happening. Additionally, their research also found that Americans think that only 54% of the country believes that climate change is happening. These figures show that there is a disconnect between perceived public perception of the issue and reality.

Differences between regions

While climate change will affect the entire world, opinion differences between regions of the world about these affects vary significantly. The Middle East has one of the smallest rates of concern in the world, especially compared to Latin America. Europe and Africa have mixed views on climate change but lean towards action by a significant degree. Europeans focus substantially on climate change when compared to United States residents, which are less concerned than the global median, even as the United States is the second biggest emitter in the world. Droughts/water shortages are one of the biggest fears about the impacts of climate change, especially in Latin America and Africa. Developed countries in Asia have levels of concern about climate change similar to Latin America which has one of the highest rates of concern. This is surprising as developing countries in Asia have levels of worry similar to the Middle East, one of the areas with the lowest levels of concern. Large emitters such as China usually ignore issues surrounding climate change as people in China have very low levels of concern about it. The only significant exception to this tendency by large emitters, is Brazil and India . India I'd the third and Brazil is eleventh biggest emitter in the world and are countries that have high levels of concern about climate change, levels similar to much of Latin America.

Percentage in each region who agree with statements regarding climate change (in 2015)
 
Region Climate change is a very serious problem Climate change is harming people now Very concerned that climate change will harm me personally
Africa 61% 52% 61%
Latin America 74% 77% 63%
Europe 54% 60% 27%
Asia/Pacific 45% 48% 37%
Middle East 38% 26% 27%
United States 45% 41% 30%
China 18% 49% 15%
Global Median 54% 51% 40%

Source: Pew Research Center's Spring 2015 Global Attitudes Survey - Q32, Q41 & Q42

Percentage of each country polled who agree with statement (in 2015)
 
Country Climate change is a very serious problem
Canada 51%
U.S. 45%
France 56%
Italy 55%
Germany 55%
Spain 53%
UK 41%
Poland 19%
Russia 33%
Ukraine 80%
Lebanon 67%
Jordan 44%
Palestine 38%
Turkey 37%
Israel 24%
India 76%
Philippines 72%
Vietnam 69%
South Korea 48%
Japan 45%
Malaysia 44%
Australia 43%
Indonesia 41%
Pakistan 29%
China 18%
Brazil 86%
Chile 77%
Peru 75%
Venezuela 72%
Mexico 66%
Argentina 59%
Burkina Faso 79%
Uganda 76%
Ghana 68%
Kenya 62%
Nigeria 61%
Senegal 58%
Tanzania 57%
South Africa 45%
Ethiopia 40%

Source: Pew Research Center's Spring 2015 Global Attitudes Survey - Q32

Developing countries vs developed countries

Awareness about climate change is higher in developed countries than in developing countries. A large majority of people in Indonesia, Pakistan and Nigeria do not know about climate change, particularly in Muslim majority countries. There is often awareness about environmental changes in developing countries, but the framework for understanding it is limited. In developing and developed countries, people similarly believe that poor countries have a responsibility to act on climate change. Since the 2009 Copenhagen summit, concern over climate change in wealthy countries has gone down. In 2009, 63% of people in OECD member states considered climate change to be "very serious" but by 2015, it had gone down to 48%. Support for national leadership creating further action addressing climate change has also gone down. Of the 21 countries surveyed in GlobeScan's 2015 survey, Canada, France, Spain and the UK are the only ones that have the majority of the population desiring their leadership to take further action to meet the emission targets set by the Paris climate accord. While concern and desire for action has gone down in developed countries, awareness over it is higher. Since 2000, twice as many people will connect extreme weather events with human caused climate change.

Scientific consensus on climate change

 
Global average temperature datasets from NASA, NOAA, Berkeley Earth, and meteorological offices of the U.K. and Japan, show substantial agreement concerning the progress and extent of global warming: pairwise correlations range from 98.09% to 99.04%.
 
Academic studies of scientific agreement on human-caused global warming among climate experts (2010-2015) reflect that the level of consensus correlates with expertise in climate science. A 2019 study found scientific consensus to be at 100%.

There is a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports.

Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. A 2019 study found scientific consensus to be at 100%.

Consensus points

The current scientific consensus is that:

Several studies of the consensus have been undertaken. Among the most cited is a 2013 study of nearly 12,000 abstracts of peer-reviewed papers on climate science published since 1990, of which just over 4,000 papers expressed an opinion on the cause of recent global warming. Of these, 97% agree, explicitly or implicitly, that global warming is happening and is human-caused. It is "extremely likely" that this warming arises from "human activities, especially emissions of greenhouse gases" in the atmosphere. Natural change alone would have had a slight cooling effect rather than a warming effect.

This scientific opinion is expressed in synthesis reports, by scientific bodies of national or international standing, and by surveys of opinion among climate scientists. Individual scientists, universities, and laboratories contribute to the overall scientific opinion via their peer-reviewed publications, and the areas of collective agreement and relative certainty are summarised in these respected reports and surveys. The IPCC's Fifth Assessment Report (AR5) was completed in 2014. Its conclusions are summarized below:

  • "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia."
  • "Atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years."
  • Human influence on the climate system is clear. It is extremely likely (95–100% probability) that human influence was the dominant cause of global warming between 1951 and 2010.
  • "Increasing magnitudes of [global] warming increase the likelihood of severe, pervasive, and irreversible impacts."
  • "A first step towards adaptation to future climate change is reducing vulnerability and exposure to present climate variability."
  • "The overall risks of climate change impacts can be reduced by limiting the rate and magnitude of climate change"
  • Without new policies to mitigate climate change, projections suggest an increase in global mean temperature in 2100 of 3.7 to 4.8 °C, relative to pre-industrial levels (median values; the range is 2.5 to 7.8 °C including climate uncertainty).
  • The current trajectory of global greenhouse gas emissions is not consistent with limiting global warming to below 1.5 or 2 °C, relative to pre-industrial levels. Pledges made as part of the Cancún Agreements are broadly consistent with cost-effective scenarios that give a "likely" chance (66–100% probability) of limiting global warming (in 2100) to below 3 °C, relative to pre-industrial levels.
The warming influence of greenhouse gases in the atmosphere has increased substantially over the last several decades. In 2017, the AGGI was 1.42, which represents an increase of more than 40% since 1990.

National and international science academies and scientific societies have assessed current scientific opinion on global warming. These assessments are generally consistent with the conclusions of the Intergovernmental Panel on Climate Change.

Some scientific bodies have recommended specific policies to governments, and science can play a role in informing an effective response to climate change. Policy decisions, however, may require value judgements and so are not included in the scientific opinion.

No scientific body of national or international standing maintains a formal opinion dissenting from any of these main points. The last national or international scientific body to drop dissent was the American Association of Petroleum Geologists, which in 2007 updated its statement to its current non-committal position. Some other organizations, primarily those focusing on geology, also hold non-committal positions.

Synthesis reports

Synthesis reports are assessments of scientific literature that compile the results of a range of stand-alone studies in order to achieve a broad level of understanding, or to describe the state of knowledge of a given subject.

Intergovernmental Panel on Climate Change (IPCC) 2014

The IPCC Fifth Assessment Report followed the same general format as the Fourth Assessment Report, with three Working Group reports and a Synthesis report. The Working Group I report (WG1) was published in September 2013. The report's Summary for Policymakers stated that warming of the climate system is 'unequivocal' with changes unprecedented over decades to millennia, including warming of the atmosphere and oceans, loss of snow and ice, and sea level rise. Greenhouse gas emissions, driven largely by economic and population growth, have led to greenhouse gas concentrations that are unprecedented in at least the last 800,000 years. These, together with other anthropogenic drivers, are "extremely likely" (where that means more than 95% probability) to have been the dominant cause of the observed global warming since the mid-20th century.

It said that

Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks.

Reporting on the publication of the report, The Guardian said that

In the end it all boils down to risk management. The stronger our efforts to reduce greenhouse gas emissions, the lower the risk of extreme climate impacts. The higher our emissions, the larger climate changes we'll face, which also means more expensive adaptation, more species extinctions, more food and water insecurities, more income losses, more conflicts, and so forth.

The New York Times reported that

In Washington, President Obama's science adviser, John P. Holdren, cited increased scientific confidence "that the kinds of harm already being experienced from climate change will continue to worsen unless and until comprehensive and vigorous action to reduce emissions is undertaken worldwide."

It went on to say that Ban Ki-moon, the United Nations secretary general, had declared his intention to call a meeting of heads of state in 2014 to develop such a treaty. The last such meeting, in Copenhagen in 2009, the NY Times reported, had ended in disarray.

Intergovernmental Panel on Climate Change (IPCC) 2007

In February 2007, the IPCC released a summary of the forthcoming Fourth Assessment Report. According to this summary, the Fourth Assessment Report found that human actions are "very likely" the cause of global warming, meaning a 90% or greater probability. Global warming in this case was indicated by an increase of 0.75 degrees in average global temperatures over the last 100 years.

The IPCC Fourth Assessment Report stated that:

  • Warming of the climate system is unequivocal, as evidenced by increases in global average air and ocean temperatures, the widespread melting of snow and ice, and rising global average sea level.
  • Most of the global warming since the mid-20th century is very likely due to human activities.
NASA time-lapse video: Global average temperatures have increased in evolving patterns in which cooler temperatures (shown in blues) have generally changed to warmer temperatures (shown in progressively intense reds).
  • Benefits and costs of climate change for [human] society will vary widely by location and scale. Some of the effects in temperate and polar regions will be positive, and others elsewhere will be negative. Overall, net effects are more likely to be strongly negative with larger or more rapid warming.
  • The range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.
  • The resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change, associated disturbances (e.g. flooding, drought, wildfire, insects, ocean acidification), and other global change drivers (e.g. land-use change, pollution, fragmentation of natural systems, over-exploitation of resources).

The New York Times reported that "the leading international network of climate scientists has concluded for the first time that global warming is 'unequivocal' and that human activity is the main driver, 'very likely' causing most of the rise in temperatures since 1950".

A retired journalist for The New York Times, William K. Stevens wrote: "The Intergovernmental Panel on Climate Change said the likelihood was 90 percent to 99 percent that emissions of heat-trapping greenhouse gases like carbon dioxide, spewed from tailpipes and smokestacks, were the dominant cause of the observed warming of the last 50 years. In the panel's parlance, this level of certainty is labeled 'very likely'. Only rarely does scientific odds-making provide a more definite answer than that, at least in this branch of science, and it describes the endpoint, so far, of a progression.".

The Associated Press summarized the position on sea level rise:

On sea levels, the report projects rises of 7 to 23 inches by the end of the century. An additional 3.9 to 7.8 inches are possible if recent, surprising melting of polar ice sheets continues.

U.S. Global Change Research Program

The Fourth National Climate Assessment ("NCA4", USGCRP, 2017) includes charts illustrating how human factors, especially accumulation in the atmosphere of greenhouse gases, are the predominant cause of observed global warming.

Thirteen federal agencies, led by the National Oceanic and Atmospheric Administration (NOAA), worked together under the auspices of the United States Global Change Research Program (USGCRP) to prepare the country's Fourth National Climate Assessment, published in two volumes as described below.

The Climate Science Special Report: Fourth National Climate Assessment, Volume I (October 2017) provided the following summary:

This assessment concludes, based on extensive evidence, that it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.

Background

The U.S. Global Change Research Program reported in June 2009 that:

Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases. These emissions come mainly from the burning of fossil fuels (coal, oil, and gas), with important contributions from the clearing of forests, agricultural practices, and other activities.

The 2009 report, which is about the effects that climate change is having in the United States, also said:

Climate-related changes have already been observed globally and in the United States. These include increases in air and water temperatures, reduced frost days, increased frequency and intensity of heavy downpours, a rise in sea level, and reduced snow cover, glaciers, permafrost, and sea ice. A longer ice-free period on lakes and rivers, lengthening of the growing season, and increased water vapor in the atmosphere have also been observed. Over the past 30 years, temperatures have risen faster in winter than in any other season, with average winter temperatures in the Midwest and northern Great Plains increasing more than 7 °F (3.9 °C). Some of the changes have been faster than previous assessments had suggested.

Arctic Climate Impact Assessment

In 2004, the intergovernmental Arctic Council and the non-governmental International Arctic Science Committee released the synthesis report of the Arctic Climate Impact Assessment:

Climate conditions in the past provide evidence that rising atmospheric carbon dioxide levels are associated with rising global temperatures. Human activities, primarily the burning of fossil fuels (coal, oil, and natural gas), and secondarily the clearing of land, have increased the concentration of carbon dioxide, methane, and other heat-trapping ("greenhouse") gases in the atmosphere...There is international scientific consensus that most of the warming observed over the last 50 years is attributable to human activities.

Policy

There is an extensive discussion in the scientific literature on what policies might be effective in responding to climate change. Some scientific bodies have recommended specific policies to governments (refer to the later sections of the article). The natural and social sciences can play a role in informing an effective response to climate change. However, policy decisions may require value judgements. For example, the US National Research Council has commented:

The question of whether there exists a "safe" level of concentration of greenhouse gases cannot be answered directly because it would require a value judgment of what constitutes an acceptable risk to human welfare and ecosystems in various parts of the world, as well as a more quantitative assessment of the risks and costs associated with the various impacts of global warming. In general, however, risk increases with increases in both the rate and the magnitude of climate change.

This article mostly focuses on the views of natural scientists. However, social scientists, medical experts, engineers and philosophers have also commented on climate change science and policies. Climate change policy is discussed in several articles: climate change mitigation, climate change adaptation, climate engineering, politics of global warming, climate ethics, and economics of global warming.

Statements by scientific organizations of national or international standing

This is a list of scientific bodies of national or international standing, that have issued formal statements of opinion, classifies those organizations according to whether they concur with the IPCC view, are non-committal, or dissent from it. The California Governor's Office website lists nearly 200 worldwide scientific organizations hold the position that climate change has been caused by human action.

Concurring

Academies of science (general science)

Since 2001, 34 national science academies, three regional academies, and both the international InterAcademy Council and International Council of Academies of Engineering and Technological Sciences have made formal declarations confirming human induced global warming and urging nations to reduce emissions of greenhouse gases. The 34 national science academy statements include 33 who have signed joint science academy statements and one individual declaration by the Polish Academy of Sciences in 2007.

Joint national science academy statements
  • 2001 Following the publication of the IPCC Third Assessment Report, seventeen national science academies issued a joint statement, entitled "The Science of Climate Change", explicitly acknowledging the IPCC position as representing the scientific consensus on climate change science. The statement, printed in an editorial in the journal Science on May 18, 2001, was signed by the science academies of Australia, Belgium, Brazil, Canada, the Caribbean, China, France, Germany, India, Indonesia, Ireland, Italy, Malaysia, New Zealand, Sweden, Turkey, and the United Kingdom.
  • 2005 The national science academies of the G8 nations, plus Brazil, China and India, three of the largest emitters of greenhouse gases in the developing world, signed a statement on the global response to climate change. The statement stresses that the scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action, and explicitly endorsed the IPCC consensus. The eleven signatories were the science academies of Brazil, Canada, China, France, Germany, India, Italy, Japan, Russia, the United Kingdom, and the United States.
  • 2007 In preparation for the 33rd G8 summit, the national science academies of the G8+5 nations issued a declaration referencing the position of the 2005 joint science academies' statement, and acknowledging the confirmation of their previous conclusion by recent research. Following the IPCC Fourth Assessment Report, the declaration states, "It is unequivocal that the climate is changing, and it is very likely that this is predominantly caused by the increasing human interference with the atmosphere. These changes will transform the environmental conditions on Earth unless counter-measures are taken." The thirteen signatories were the national science academies of Brazil, Canada, China, France, Germany, Italy, India, Japan, Mexico, Russia, South Africa, the United Kingdom, and the United States.
  • 2007 In preparation for the 33rd G8 summit, the Network of African Science Academies submitted a joint "statement on sustainability, energy efficiency, and climate change":

    A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change. The IPCC should be congratulated for the contribution it has made to public understanding of the nexus that exists between energy, climate and sustainability.

    — The thirteen signatories were the science academies of Cameroon, Ghana, Kenya, Madagascar, Nigeria, Senegal, South Africa, Sudan, Tanzania, Uganda, Zambia, Zimbabwe, as well as the African Academy of Sciences
  • 2008 In preparation for the 34th G8 summit, the national science academies of the G8+5 nations issued a declaration reiterating the position of the 2005 joint science academies’ statement, and reaffirming "that climate change is happening and that anthropogenic warming is influencing many physical and biological systems". Among other actions, the declaration urges all nations to "[t]ake appropriate economic and policy measures to accelerate transition to a low carbon society and to encourage and effect changes in individual and national behaviour". The thirteen signatories were the same national science academies that issued the 2007 joint statement.
  • 2009 In advance of the UNFCCC negotiations to be held in Copenhagen in December 2009, the national science academies of the G8+5 nations issued a joint statement declaring, "Climate change and sustainable energy supply are crucial challenges for the future of humanity. It is essential that world leaders agree on the emission reductions needed to combat negative consequences of anthropogenic climate change". The statement references the IPCC's Fourth Assessment of 2007, and asserts that "climate change is happening even faster than previously estimated; global CO
    2
    emissions since 2000 have been higher than even the highest predictions, Arctic sea ice has been melting at rates much faster than predicted, and the rise in the sea level has become more rapid". The thirteen signatories were the same national science academies that issued the 2007 and 2008 joint statements.
Polish Academy of Sciences

In December 2007, the General Assembly of the Polish Academy of Sciences (Polska Akademia Nauk), which has not been a signatory to joint national science academy statements issued a declaration endorsing the IPCC conclusions, and stating:

it is the duty of Polish science and the national government to, in a thoughtful, organized and active manner, become involved in realisation of these ideas.

Problems of global warming, climate change, and their various negative impacts on human life and on the functioning of entire societies are one of the most dramatic challenges of modern times.

PAS General Assembly calls on the national scientific communities and the national government to actively support Polish participation in this important endeavor.

Additional national science academy and society statements
  • American Association for the Advancement of Science as the world's largest general scientific society, adopted an official statement on climate change in 2006:

    The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society....The pace of change and the evidence of harm have increased markedly over the last five years. The time to control greenhouse gas emissions is now.

  • Federation of Australian Scientific and Technological Societies in 2008 published FASTS Statement on Climate Change which states:

    Global climate change is real and measurable...To reduce the global net economic, environmental and social losses in the face of these impacts, the policy objective must remain squarely focused on returning greenhouse gas concentrations to near pre-industrial levels through the reduction of emissions. The spatial and temporal fingerprint of warming can be traced to increasing greenhouse gas concentrations in the atmosphere, which are a direct result of burning fossil fuels, broad-scale deforestation and other human activity.

  • United States National Research Council through its Committee on the Science of Climate Change in 2001, published Climate Change Science: An Analysis of Some Key Questions. This report explicitly endorses the IPCC view of attribution of recent climate change as representing the view of the scientific community:

    The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability. Human-induced warming and associated sea level rises are expected to continue through the 21st century... The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue.

  • Royal Society of New Zealand having signed onto the first joint science academy statement in 2001, released a separate statement in 2008 in order to clear up "the controversy over climate change and its causes, and possible confusion among the public":

    The globe is warming because of increasing greenhouse gas emissions. Measurements show that greenhouse gas concentrations in the atmosphere are well above levels seen for many thousands of years. Further global climate changes are predicted, with impacts expected to become more costly as time progresses. Reducing future impacts of climate change will require substantial reductions of greenhouse gas emissions.

  • The Royal Society of the United Kingdom has not changed its concurring stance reflected in its participation in joint national science academies' statements on anthropogenic global warming. According to the Telegraph, "The most prestigious group of scientists in the country was forced to act after fellows complained that doubts over man made global warming were not being communicated to the public". In May 2010, it announced that it "is presently drafting a new public facing document on climate change, to provide an updated status report on the science in an easily accessible form, also addressing the levels of certainty of key components." The society says that it is three years since the last such document was published and that, after an extensive process of debate and review, the new document was printed in September 2010. It summarises the current scientific evidence and highlights the areas where the science is well established, where there is still some debate, and where substantial uncertainties remain. The society has stated that "this is not the same as saying that the climate science itself is in error – no Fellows have expressed such a view to the RS". The introduction includes this statement:

    There is strong evidence that the warming of the Earth over the last half-century has been caused largely by human activity, such as the burning of fossil fuels and changes in land use, including agriculture and deforestation.

International science academies
  • African Academy of Sciences in 2007 was a signatory to the "statement on sustainability, energy efficiency, and climate change". This joint statement of African science academies, was organized through the Network of African Science Academies. Its stated goal was "to convey information and spur action on the occasion of the G8 Summit in Heiligendamm, Germany, in June 2007".

    A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change.

  • European Academy of Sciences and Arts in 2007 issued a formal declaration on climate change titled Let's Be Honest:

    Human activity is most likely responsible for climate warming. Most of the climatic warming over the last 50 years is likely to have been caused by increased concentrations of greenhouse gases in the atmosphere. Documented long-term climate changes include changes in Arctic temperatures and ice, widespread changes in precipitation amounts, ocean salinity, wind patterns and extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones. The above development potentially has dramatic consequences for mankind's future.

  • European Science Foundation in a 2007 position paper states:

    There is now convincing evidence that since the industrial revolution, human activities, resulting in increasing concentrations of greenhouse gases have become a major agent of climate change ... On-going and increased efforts to mitigate climate change through reduction in greenhouse gases are therefore crucial.

  • InterAcademy Council As the representative of the world's scientific and engineering academies, the InterAcademy Council issued a report in 2007 titled Lighting the Way: Toward a Sustainable Energy Future.

    Current patterns of energy resources and energy usage are proving detrimental to the long-term welfare of humanity. The integrity of essential natural systems is already at risk from climate change caused by the atmospheric emissions of greenhouse gases. Concerted efforts should be mounted for improving energy efficiency and reducing the carbon intensity of the world economy.

  • International Council of Academies of Engineering and Technological Sciences (CAETS) in 2007, issued a Statement on Environment and Sustainable Growth:

    As reported by the Intergovernmental Panel on Climate Change (IPCC), most of the observed global warming since the mid-20th century is very likely due to human-produced emission of greenhouse gases and this warming will continue unabated if present anthropogenic emissions continue or, worse, expand without control. CAETS, therefore, endorses the many recent calls to decrease and control greenhouse gas emissions to an acceptable level as quickly as possible.

Physical and chemical sciences

Earth sciences

American Geophysical Union

The American Geophysical Union (AGU) adopted a statement on Climate Change and Greenhouse Gases in 1998. A new statement, adopted by the society in 2003, revised in 2007, and revised and expanded in 2013, affirms that rising levels of greenhouse gases have caused and will continue to cause the global surface temperature to be warmer:

Human activities are changing Earth's climate. At the global level, atmospheric concentrations of carbon dioxide and other heat-trapping greenhouse gases have increased sharply since the Industrial Revolution. Fossil fuel burning dominates this increase. Human-caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8 °C (1.5 °F) over the past 140 years. Because natural processes cannot quickly remove some of these gases (notably carbon dioxide) from the atmosphere, our past, present, and future emissions will influence the climate system for millennia. While important scientific uncertainties remain as to which particular impacts will be experienced where, no uncertainties are known that could make the impacts of climate change inconsequential. Furthermore, surprise outcomes, such as the unexpectedly rapid loss of Arctic summer sea ice, may entail even more dramatic changes than anticipated.

American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America

In May, 2011, the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and Soil Science Society of America (SSSA) issued a joint position statement on climate change as it relates to agriculture:

A comprehensive body of scientific evidence indicates beyond reasonable doubt that global climate change is now occurring and that its manifestations threaten the stability of societies as well as natural and managed ecosystems. Increases in ambient temperatures and changes in related processes are directly linked to rising anthropogenic greenhouse gas (GHG) concentrations in the atmosphere.

Unless the emissions of GHGs are curbed significantly, their concentrations will continue to rise, leading to changes in temperature, precipitation, and other climate variables that will undoubtedly affect agriculture around the world.

Climate change has the potential to increase weather variability as well as gradually increase global temperatures. Both of these impacts have the potential to negatively impact the adaptability and resilience of the world's food production capacity; current research indicates climate change is already reducing the productivity of vulnerable cropping systems.

European Federation of Geologists

In 2008, the European Federation of Geologists (EFG) issued the position paper Carbon Capture and geological Storage :

The EFG recognizes the work of the IPCC and other organizations, and subscribes to the major findings that climate change is happening, is predominantly caused by anthropogenic emissions of CO
2
, and poses a significant threat to human civilization.

It is clear that major efforts are necessary to quickly and strongly reduce CO
2
emissions. The EFG strongly advocates renewable and sustainable energy production, including geothermal energy, as well as the need for increasing energy efficiency.

CCS [Carbon Capture and geological Storage] should also be regarded as a bridging technology, facilitating the move towards a carbon free economy.

European Geosciences Union

In 2005, the Divisions of Atmospheric and Climate Sciences of the European Geosciences Union (EGU) issued a position statement in support of the joint science academies’ statement on global response to climate change. The statement refers to the Intergovernmental Panel on Climate Change (IPCC), as "the main representative of the global scientific community", and asserts that the IPCC

represents the state-of-the-art of climate science supported by the major science academies around the world and by the vast majority of science researchers and investigators as documented by the peer-reviewed scientific literature.

Additionally, in 2008, the EGU issued a position statement on ocean acidification which states, "Ocean acidification is already occurring today and will continue to intensify, closely tracking atmospheric CO
2
increase. Given the potential threat to marine ecosystems and its ensuing impact on human society and economy, especially as it acts in conjunction with anthropogenic global warming, there is an urgent need for immediate action." The statement then advocates for strategies "to limit future release of CO
2
to the atmosphere and/or enhance removal of excess CO
2
from the atmosphere". And, in 2018 the EGU issued a statement concurring with the findings of the Special Report on Global Warming of 1.5 °C, with Jonathan Bamber, president of the organisation, noting: “EGU concurs with, and supports, the findings of the SR15 that action to curb the most dangerous consequences of human-induced climate change is urgent, of the utmost importance and the window of opportunity extremely limited.”

Geological Society of America

In 2006, the Geological Society of America adopted a position statement on global climate change. It amended this position on April 20, 2010, with more explicit comments on need for CO
2
reduction.

Decades of scientific research have shown that climate can change from both natural and anthropogenic causes. The Geological Society of America (GSA) concurs with assessments by the National Academies of Science (2005), the National Research Council (2006), and the Intergovernmental Panel on Climate Change (IPCC, 2007) that global climate has warmed and that human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s. If current trends continue, the projected increase in global temperature by the end of the twenty first century will result in large impacts on humans and other species. Addressing the challenges posed by climate change will require a combination of adaptation to the changes that are likely to occur and global reductions of CO
2
emissions from anthropogenic sources.

Geological Society of London

In November 2010, the Geological Society of London issued the position statement Climate change: evidence from the geological record:

The last century has seen a rapidly growing global population and much more intensive use of resources, leading to greatly increased emissions of gases, such as carbon dioxide and methane, from the burning of fossil fuels (oil, gas and coal), and from agriculture, cement production and deforestation. Evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to: higher sea levels and flooding of low-lying coasts; greatly changed patterns of rainfall; increased acidity of the oceans; and decreased oxygen levels in seawater. There is now widespread concern that the Earth's climate will warm further, not only because of the lingering effects of the added carbon already in the system, but also because of further additions as human population continues to grow. Life on Earth has survived large climate changes in the past, but extinctions and major redistribution of species have been associated with many of them. When the human population was small and nomadic, a rise in sea level of a few metres would have had very little effect on Homo sapiens. With the current and growing global population, much of which is concentrated in coastal cities, such a rise in sea level would have a drastic effect on our complex society, especially if the climate were to change as suddenly as it has at times in the past. Equally, it seems likely that as warming continues some areas may experience less precipitation leading to drought. With both rising seas and increasing drought, pressure for human migration could result on a large scale.

International Union of Geodesy and Geophysics

In July 2007, the International Union of Geodesy and Geophysics (IUGG) adopted a resolution titled "The Urgency of Addressing Climate Change". In it, the IUGG concurs with the "comprehensive and widely accepted and endorsed scientific assessments carried out by the Intergovernmental Panel on Climate Change and regional and national bodies, which have firmly established, on the basis of scientific evidence, that human activities are the primary cause of recent climate change". They state further that the "continuing reliance on combustion of fossil fuels as the world's primary source of energy will lead to much higher atmospheric concentrations of greenhouse gases, which will, in turn, cause significant increases in surface temperature, sea level, ocean acidification, and their related consequences to the environment and society".

National Association of Geoscience Teachers

In July 2009, the National Association of Geoscience Teachers (NAGT) adopted a position statement on climate change in which they assert that "Earth's climate is changing [and] "that present warming trends are largely the result of human activities":

NAGT strongly supports and will work to promote education in the science of climate change, the causes and effects of current global warming, and the immediate need for policies and actions that reduce the emission of greenhouse gases.

Meteorology and oceanography

American Meteorological Society

The American Meteorological Society (AMS) statement adopted by their council in 2012 concluded:

There is unequivocal evidence that Earth's lower atmosphere, ocean, and land surface are warming; sea level is rising; and snow cover, mountain glaciers, and Arctic sea ice are shrinking. The dominant cause of the warming since the 1950s is human activities. This scientific finding is based on a large and persuasive body of research. The observed warming will be irreversible for many years into the future, and even larger temperature increases will occur as greenhouse gases continue to accumulate in the atmosphere. Avoiding this future warming will require a large and rapid reduction in global greenhouse gas emissions. The ongoing warming will increase risks and stresses to human societies, economies, ecosystems, and wildlife through the 21st century and beyond, making it imperative that society respond to a changing climate. To inform decisions on adaptation and mitigation, it is critical that we improve our understanding of the global climate system and our ability to project future climate through continued and improved monitoring and research. This is especially true for smaller (seasonal and regional) scales and weather and climate extremes, and for important hydroclimatic variables such as precipitation and water availability. Technological, economic, and policy choices in the near future will determine the extent of future impacts of climate change. Science-based decisions are seldom made in a context of absolute certainty. National and international policy discussions should include consideration of the best ways to both adapt to and mitigate climate change. Mitigation will reduce the amount of future climate change and the risk of impacts that are potentially large and dangerous. At the same time, some continued climate change is inevitable, and policy responses should include adaptation to climate change. Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life.

A 2016 survey found that two-thirds of AMS members think that all or most of climate change is caused by human activity.

Australian Meteorological and Oceanographic Society

The Australian Meteorological and Oceanographic Society has issued a Statement on Climate Change, wherein they conclude:

Global climate change and global warming are real and observable ... It is highly likely that those human activities that have increased the concentration of greenhouse gases in the atmosphere have been largely responsible for the observed warming since 1950. The warming associated with increases in greenhouse gases originating from human activity is called the enhanced greenhouse effect. The atmospheric concentration of carbon dioxide has increased by more than 30% since the start of the industrial age and is higher now than at any time in at least the past 650,000 years. This increase is a direct result of burning fossil fuels, broad-scale deforestation and other human activity.

Canadian Foundation for Climate and Atmospheric Sciences

In November 2005, the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) issued a letter to the Prime Minister of Canada stating that

We concur with the climate science assessment of the Intergovernmental Panel on Climate Change (IPCC) in 2001 ... We endorse the conclusions of the IPCC assessment that 'There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities'. ... There is increasingly unambiguous evidence of changing climate in Canada and around the world. There will be increasing impacts of climate change on Canada's natural ecosystems and on our socio-economic activities. Advances in climate science since the 2001 IPCC Assessment have provided more evidence supporting the need for action and development of a strategy for adaptation to projected changes.

Canadian Meteorological and Oceanographic Society

In November 2009, a letter to the Canadian Parliament by The Canadian Meteorological and Oceanographic Society states:

Rigorous international research, including work carried out and supported by the Government of Canada, reveals that greenhouse gases resulting from human activities contribute to the warming of the atmosphere and the oceans and constitute a serious risk to the health and safety of our society, as well as having an impact on all life.

Royal Meteorological Society (UK)

In February 2007, after the release of the IPCC's Fourth Assessment Report, the Royal Meteorological Society issued an endorsement of the report. In addition to referring to the IPCC as "[the] world's best climate scientists", they stated that climate change is happening as "the result of emissions since industrialization and we have already set in motion the next 50 years of global warming – what we do from now on will determine how worse it will get."

World Meteorological Organization

In its Statement at the Twelfth Session of the Conference of the Parties to the U.N. Framework Convention on Climate Change presented on November 15, 2006, the World Meteorological Organization (WMO) confirms the need to "prevent dangerous anthropogenic interference with the climate system". The WMO concurs that "scientific assessments have increasingly reaffirmed that human activities are indeed changing the composition of the atmosphere, in particular through the burning of fossil fuels for energy production and transportation". The WMO concurs that "the present atmospheric concentration of CO
2
was never exceeded over the past 420,000 years"; and that the IPCC "assessments provide the most authoritative, up-to-date scientific advice".

American Quaternary Association

The American Quaternary Association (AMQUA) has stated

Few credible scientists now doubt that humans have influenced the documented rise in global temperatures since the Industrial Revolution. The first government-led U.S. Climate Change Science Program synthesis and assessment report supports the growing body of evidence that warming of the atmosphere, especially over the past 50 years, is directly impacted by human activity.

International Union for Quaternary Research

The statement on climate change issued by the International Union for Quaternary Research (INQUA) reiterates the conclusions of the IPCC, and urges all nations to take prompt action in line with the UNFCCC principles.

Human activities are now causing atmospheric concentrations of greenhouse gases—including carbon dioxide, methane, tropospheric ozone, and nitrous oxide—to rise well above pre-industrial levels ... Increases in greenhouse gases are causing temperatures to rise ... The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action ... Minimizing the amount of this carbon dioxide reaching the atmosphere presents a huge challenge but must be a global priority.

Biology and life sciences

Life science organizations have outlined the dangers climate change pose to wildlife.

Human health

A number of health organizations have warned about the numerous negative health effects of global warming:

There is now widespread agreement that the Earth is warming, due to emissions of greenhouse gases caused by human activity. It is also clear that current trends in energy use, development, and population growth will lead to continuing – and more severe – climate change.

The changing climate will inevitably affect the basic requirements for maintaining health: clean air and water, sufficient food and adequate shelter. Each year, about 800,000 people die from causes attributable to urban air pollution, 1.8 million from diarrhoea resulting from lack of access to clean water supply, sanitation, and poor hygiene, 3.5 million from malnutrition and approximately 60,000 in natural disasters. A warmer and more variable climate threatens to lead to higher levels of some air pollutants, increase transmission of diseases through unclean water and through contaminated food, to compromise agricultural production in some of the least developed countries, and increase the hazards of extreme weather.

The Bulletin of the Atomic scientists and "Doomsday clock"

In 1945, Albert Einstein and other scientists who created atomic weapons used in the atomic bombings of Hiroshima and Nagasaki founded the "Bulletin of the Atomic Scientists" and created the "Doomsday Clock." The goal of the clock is to convey threats to humanity and the planet, and to create public awareness that will lead to solutions. In the beginning, the Doomsday Clock focused on the dangers of nuclear war, but in the 21th century, it has begun to deal with other issues like climate change and disinformation on the internet.

On 23 January 2020 the organization moved the doomsday clock to 100 seconds before midnight, closer than ever. It explained that it did it because of 3 factors:

  • Increasing danger of nuclear war,
  • Increasing danger from climate change, and
  • Increasing danger from disinformation in the internet regarding the issues in points 1 and 2 and other "disruptive technologies".

The organization praised the climate movement of young people and called to citizens and governments to act to take greater action on climate change.

Miscellaneous

A number of other national scientific societies have also endorsed the opinion of the IPCC:

Non-committal

American Association of Petroleum Geologists

As of June 2007, the American Association of Petroleum Geologists (AAPG) Position Statement on climate change stated:

the AAPG membership is divided on the degree of influence that anthropogenic CO
2
has on recent and potential global temperature increases ... Certain climate simulation models predict that the warming trend will continue, as reported through NAS, AGU, AAAS and AMS. AAPG respects these scientific opinions but wants to add that the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data. These data do not necessarily support the maximum case scenarios forecast in some models.

Prior to the adoption of this statement, the AAPG was the only major scientific organization that rejected the finding of significant human influence on recent climate, according to a statement by the Council of the American Quaternary Association. Explaining the plan for a revision, AAPG president Lee Billingsly wrote in March 2007:

Members have threatened to not renew their memberships ... if AAPG does not alter its position on global climate change ... And I have been told of members who already have resigned in previous years because of our current global climate change position ... The current policy statement is not supported by a significant number of our members and prospective members.

AAPG President John Lorenz announced the "sunsetting" of AAPG's Global Climate Change Committee in January 2010. The AAPG Executive Committee determined:

Climate change is peripheral at best to our science ... AAPG does not have credibility in that field ... and as a group we have no particular knowledge of global atmospheric geophysics.

American Institute of Professional Geologists (AIPG)

The official position statement from AIPG on the Environment states that "combustion of fossil fuel include and the generation of GHGs [greenhouse gases] including carbon dioxide (CO2) and methane (CH4). Emissions of GHGs are perceived by some to be one of the largest, global environmental concerns related to energy production due to potential effects on the global energy system and possibly global climate. Fossil fuel use is the primary source of the increased atmospheric concentration of GHGs since industrialization".

In March 2010, AIPG's Executive Director issued a statement regarding polarization of opinions on climate change within the membership and announced that the AIPG Executive had made a decision to cease publication of articles and opinion pieces concerning climate change in AIPG's news journal, The Professional Geologist.

Opposing

Since 2007, when the American Association of Petroleum Geologists released a revised statement, no longer does any national or international scientific body reject the findings of human-induced effects on climate change.

Surveys of scientists and scientific literature

Various surveys have been conducted to evaluate scientific opinion on global warming. They have concluded that almost all climate scientists support the idea of anthropogenic climate change.

In 2004, the geologist and historian of science Naomi Oreskes summarized a study of the scientific literature on climate change. She analyzed 928 abstracts of papers from refereed scientific journals between 1993 and 2003 and concluded that there is a scientific consensus on the reality of anthropogenic climate change.

Oreskes divided the abstracts into six categories: explicit endorsement of the consensus position, evaluation of impacts, mitigation proposals, methods, paleoclimate analysis, and rejection of the consensus position. Seventy-five per cent of the abstracts were placed in the first three categories (either explicitly or implicitly accepting the consensus view); 25% dealt with methods or paleoclimate, thus taking no position on current anthropogenic climate change. None of the abstracts disagreed with the consensus position, which the author found to be "remarkable". According to the report, "authors evaluating impacts, developing methods, or studying paleoclimatic change might believe that current climate change is natural. However, none of these papers argued that point."

In 2007, Harris Interactive surveyed 489 randomly selected members of either the American Meteorological Society or the American Geophysical Union for the Statistical Assessment Service (STATS) at George Mason University. 97% of the scientists surveyed agreed that global temperatures had increased during the past 100 years; 84% said they personally believed human-induced warming was occurring, and 74% agreed that "currently available scientific evidence" substantiated its occurrence. Catastrophic effects in 50–100 years would likely be observed according to 41%, while 44% thought the effects would be moderate and about 13 percent saw relatively little danger. 5% said they thought human activity did not contribute to greenhouse warming.

Dennis Bray and Hans von Storch conducted a survey in August 2008 of 2058 climate scientists from 34 different countries. A web link with a unique identifier was given to each respondent to eliminate multiple responses. A total of 373 responses were received giving an overall response rate of 18.2%. No paper on climate change consensus based on this survey has been published yet (February 2010), but one on another subject has been published based on the survey.

The survey was made up of 76 questions split into a number of sections. There were sections on the demographics of the respondents, their assessment of the state of climate science, how good the science is, climate change impacts, adaptation and mitigation, their opinion of the IPCC, and how well climate science was being communicated to the public. Most of the answers were on a scale from 1 to 7 from "not at all" to "very much".

To the question "How convinced are you that climate change, whether natural or anthropogenic, is occurring now?", 67.1% said they very much agreed, 26.7% agreed to some large extent, 6.2% said to they agreed to some small extent (2–4), none said they did not agree at all. To the question "How convinced are you that most of recent or near future climate change is, or will be, a result of anthropogenic causes?" the responses were 34.6% very much agree, 48.9% agreeing to a large extent, 15.1% to a small extent, and 1.35% not agreeing at all.

A poll performed by Peter Doran and Maggie Kendall Zimmerman at University of Illinois at Chicago received replies from 3,146 of the 10,257 polled Earth scientists. Results were analyzed globally and by specialization. 76 out of 79 climatologists who "listed climate science as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change" believed that mean global temperatures had risen compared to pre-1800s levels. Seventy-five of 77 believed that human activity is a significant factor in changing mean global temperatures. Among all respondents, 90% agreed that temperatures have risen compared to pre-1800 levels, and 82% agreed that humans significantly influence the global temperature. Economic geologists and meteorologists were among the biggest doubters, with only 47 percent and 64 percent, respectively, believing in significant human involvement. The authors summarised the findings:

It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes.

A 2010 paper in the Proceedings of the National Academy of Sciences of the United States (PNAS) reviewed publication and citation data for 1,372 climate researchers and drew the following two conclusions:

(i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC (Anthropogenic Climate Change) outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.

A 2013 paper in Environmental Research Letters reviewed 11,944 abstracts of scientific papers matching "global warming" or "global climate change". They found 4,014 which discussed the cause of recent global warming, and of these "97.1% endorsed the consensus position that humans are causing global warming". This study was criticised in 2016 by Richard Tol, but strongly defended by a companion paper in the same volume.

Peer-reviewed studies of the consensus on anthropogenic global warming.

A 2012 analysis of published research on global warming and climate change between 1991 and 2012 found that of the 13,950 articles in peer-reviewed journals, only 24 rejected anthropogenic global warming. A follow-up analysis looking at 2,258 peer-reviewed climate articles with 9,136 authors published between November 2012 and December 2013 revealed that only one of the 9,136 authors rejected anthropogenic global warming. His 2015 paper on the topic, covering 24,210 articles published by 69,406 authors during 2013 and 2014 found only five articles by four authors rejecting anthropogenic global warming. Over 99.99% of climate scientists did not reject AGW in their peer-reviewed research.

James Lawrence Powell reported in 2017 that using rejection as the criterion of consensus, five surveys of the peer-reviewed literature from 1991 to 2015, including several of those above, combine to 54,195 articles with an average consensus of 99.94%. In November 2019, his survey of over 11,600 peer-reviewed articles published in the first seven months of 2019 showed that the consensus had reached 100%.

Existence of a scientific consensus

A question that frequently arises in popular discussion is whether there is a scientific consensus on climate change. Several scientific organizations have explicitly used the term "consensus" in their statements:

  • American Association for the Advancement of Science, 2006: "The conclusions in this statement reflect the scientific consensus represented by, for example, the Intergovernmental Panel on Climate Change, and the Joint National Academies' statement."
  • US National Academy of Sciences: "In the judgment of most climate scientists, Earth's warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere. ... On climate change, [the National Academies’ reports] have assessed consensus findings on the science ..."
  • Joint Science Academies' statement, 2005: "We recognise the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC)."
  • Joint Science Academies' statement, 2001: "The work of the Intergovernmental Panel on Climate Change (IPCC) represents the consensus of the international scientific community on climate change science. We recognise IPCC as the world's most reliable source of information on climate change and its causes, and we endorse its method of achieving this consensus."
  • American Meteorological Society, 2003: "The nature of science is such that there is rarely total agreement among scientists. Individual scientific statements and papers—the validity of some of which has yet to be assessed adequately—can be exploited in the policy debate and can leave the impression that the scientific community is sharply divided on issues where there is, in reality, a strong scientific consensus ... IPCC assessment reports are prepared at approximately five-year intervals by a large international group of experts who represent the broad range of expertise and perspectives relevant to the issues. The reports strive to reflect a consensus evaluation of the results of the full body of peer-reviewed research ... They provide an analysis of what is known and not known, the degree of consensus, and some indication of the degree of confidence that can be placed on the various statements and conclusions."
  • Network of African Science Academies: "A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change."
  • International Union for Quaternary Research, 2008: "INQUA recognizes the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC)."
  • Australian Coral Reef Society, 2006: "There is almost total consensus among experts that the earth's climate is changing as a result of the build-up of greenhouse gases ... There is broad scientific consensus that coral reefs are heavily affected by the activities of man and there are significant global influences that can make reefs more vulnerable such as global warming ..."

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