James Hansen
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|---|---|
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| Born |
James Edward Hansen
March 29, 1941 |
| Nationality | American |
| Alma mater | University of Iowa |
| Known for | |
| Awards |
Heinz Award in the Environment (2001) |
| Scientific career | |
| Fields | Atmospheric physics |
| Institutions | Currently Columbia University; NASA Goddard Institute for Space Studies 1967–2013 |
| Thesis | The atmosphere of Venus : a dust insulation model (1967) |
| Doctoral advisor | Satoshi Matsushima |
| Influences | James Van Allen |
| Website | www |
James Edward Hansen (born 29 March 1941) is an American adjunct professor directing the Program on Climate Science, Awareness and Solutions of the Earth Institute at Columbia University. He is best known for his research in climatology, his 1988 Congressional testimony on climate change that helped raise broad awareness of global warming, and his advocacy of action to avoid dangerous climate change. In recent years he has become a climate activist to mitigate the effects of global warming, on a few occasions leading to his arrest.
Early life and education
Hansen was born in Denison, Iowa, to James Ivan Hansen and Gladys Ray Hansen. He was trained in physics and astronomy in the space science program of James Van Allen at the University of Iowa. He obtained a B.A. in Physics and Mathematics with highest distinction in 1963, an M.S. in Astronomy in 1965 and a Ph.D.
in Physics in 1967, all three degrees from the University of Iowa. He
participated in the NASA graduate traineeship from 1962 to 1966 and, at
the same time, between 1965 and 1966, he was a visiting student at the
Institute of Astrophysics at the University of Kyoto and in the Department of Astronomy at the University of Tokyo. He then began work at the Goddard Institute for Space Studies in 1967.
Career
After graduate school, Hansen continued his work with radiative transfer models, attempting to understand the Venusian atmosphere. He later applied and refined these models to understand the Earth's atmosphere, and in particular, the effects that aerosols and trace gases have on Earth's climate. His development and use of global climate models has contributed to the further understanding of the Earth's climate. In 2009 his first book, Storms of My Grandchildren, was published. In 2012 he presented the TED Talk "Why I must speak out about climate change".
From 1981 to 2013, he was the director of the NASA Goddard Institute for Space Studies in New York City, a part of the Goddard Space Flight Center.
As of 2014, Hansen directs the Program on Climate Science, Awareness and Solutions at Columbia University's Earth Institute.
The program is working to continue to "connect the dots" from advancing
basic climate science to promoting public awareness to advocating
policy actions.
Hansen is representing his granddaughter as well as "future generations" as plaintiffs in the Juliana v. United States
lawsuit, which is suing the United States government and some of its
executive branch's positions for not protecting a stable climate system.
Research and publications
As a college student at the University of Iowa, Hansen was attracted to science and the research done by James Van Allen's space science
program in the physics and astronomy department. A decade later, his
focus shifted to planetary research that involved trying to understand
the climate change on earth that will result from anthropogenic changes of the atmospheric composition.
Hansen has stated that one of his research interests is radiative
transfer in planetary atmospheres, especially the interpretation of remote sensing
of the Earth's atmosphere and surface from satellites. Because of the
ability of satellites to monitor the entire globe, they may be one of
the most effective ways to monitor and study global change. His other
interests include the development of global circulation models to help understand the observed climate trends, and diagnosing human impacts on climate.
Studies of Venus
Venus is surrounded by a thick atmosphere
composed mainly of carbon dioxide and nitrogen, and its clouds are
sulfuric acid. The thickness of the atmosphere initially made it
difficult to determine why the surface was so hot.
In the late 1960s and early 1970s, following his Ph.D. dissertation, Hansen published several papers on the planet Venus. Venus has a high brightness temperature
in the radio frequencies compared to the infrared. He proposed that the
hot surface was the result of aerosols trapping the internal energy of
the planet. More recent studies have suggested that several billion years ago, Venus's atmosphere
was much more like Earth's than it is now and that there were probably
substantial quantities of liquid water on the surface, but a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere.
Hansen continued his study of Venus by looking at the composition of its clouds.
He looked at the near-infrared reflectivity of ice clouds, compared
them to observations of Venus, and found that they qualitatively agreed. He also was able to use a radiative transfer model to establish an upper limit to the size of the ice particles if the clouds were actually made of ice. Evidence published in the early 1980s showed that the clouds consist mainly of sulfur dioxide and sulfuric acid droplets.
By 1974, the composition of Venus' clouds had not yet been
determined, with many scientists proposing a wide variety of compounds,
including liquid water and aqueous solutions of ferrous chloride. Hansen
and Hovenier used the polarization of sunlight reflected from the
planet to establish that the clouds were spherical and had a refractive index and cloud drop effective radius which eliminated all of the proposed cloud types except sulfuric acid. Kiyoshi Kawabata
and Hansen expanded upon this work by looking at the variation of
polarization on Venus. They found that the visible clouds are a diffuse
haze rather than a thick cloud, confirming the same results obtained
from transits across the sun.
The Pioneer Venus project was launched in May 1978 and reached Venus late that same year. Hansen collaborated with Larry Travis and other colleagues in a 1979 Science
article that reported on the development and variability of clouds in
the ultraviolet spectrum. They concluded that there are at least three
different cloud materials that contribute to the images: a thin haze
layer, sulfuric acid clouds and an unknown ultraviolet absorber below
the sulfuric acid cloud layer. The linear polarization data obtained from the same mission confirmed that the low- and mid-level clouds were sulfuric acid with radius of about 1 micrometer. Above the cloud layer was a layer of submicrometre haze.
Global temperature analysis
A typical automated airport weather station
which records the routine hourly weather observations of temperature,
weather type, wind, sky condition, and visibility. These surface
stations are located around the world, and are used to derive a global temperature.
The first GISS (NASA Goddard Institute for Space Studies)
global temperature analysis was published in 1981. Hansen and his
co-author analyzed the surface air temperature at meteorological
stations focusing on the years from 1880 to 1985. Temperatures for
stations closer together than 1000 kilometers were shown to be highly
correlated, especially in the mid-latitudes, providing a way to combine
the station data to provide accurate long-term variations. They
concluded that global mean temperatures can be determined even though
meteorological stations are typically in the Northern hemisphere and
confined to continental regions. Warming in the past century was found
to be 0.5-0.7 °C, with warming similar in both hemispheres.
When the analysis was updated in 1988, the four warmest years on record
were all in the 1980s. The two warmest years were 1981 and 1987.
During a senate meeting on June 23, 1988, Hansen reported that he was
ninety-nine percent certain the earth was warmer then than it had ever
been measured to be, there was a clear cause and effect relationship
with the greenhouse effect and lastly that due to global warming, the
likelihood of freak weather was steadily increasing.
With the 1991 eruption of Mount Pinatubo, 1992 saw a cooling in
global temperatures. There was speculation that this would cause the
next couple of years to be cooler because of the large serial correlation in the global temperatures. Bassett and Lin found the statistical odds of a new temperature record to be small.
Hansen countered by saying that having insider information shifted the
odds to those who know the physics of the climate system, and that
whether there is a new temperature record depends upon the particular
data set used.
The temperature data was updated in 1999 to report that 1998 was
the warmest year since the instrumental data began in 1880. They also
found that the rate of temperature change was larger than at any time in
instrument history, and concluded that the recent El Niño
was not solely responsible for the large temperature anomaly in 1998.
In spite of this, the United States had seen a smaller degree of
warming, and a region in the eastern U.S. and the western Atlantic Ocean
had actually cooled slightly.
2001 saw a major update to how the temperature was calculated. It
incorporated corrections due to the following reasons:
time-of-observation bias; station history changes; classification of
rural/urban station; the urban adjustment based on satellite
measurements of night light intensity, and relying more on rural station
than urban. Evidence was found of local urban warming in urban,
suburban and small-town records.
The anomalously high global temperature in 1998 due to El Niño resulted in a brief drop in subsequent years. However, a 2001 Hansen report in the journal Science
states that global warming continues, and that the increasing
temperatures should stimulate discussions on how to slow global warming. The temperature data was updated in 2006 to report that temperatures are now 0.8 °C warmer than a century ago, and concluded that the recent global warming is a real climate change and not an artifact from the urban heat island effect.
The regional variation of warming, with more warming in the higher
latitudes, is further evidence of warming that is anthropogenic in
origin.
In 2007, Stephen McIntyre notified GISS that many of the U.S. temperature records from the Historical Climatology Network
(USHCN) displayed a discontinuity around the year 2000. NASA corrected
the computer code used to process the data and credited McIntyre with
pointing out the flaw. Hansen indicated that he felt that several news organizations had overreacted to this mistake. In 2010, Hansen published a paper entitled "Global Surface Temperature Change" describing current global temperature analysis.
Black carbon studies
The incomplete combustion of biomass during the Yellowstone fires of 1988 near the Snake River introduced a large quantity of black carbon particles into the atmosphere.
Hansen has also contributed toward the understanding of black carbon
on regional climate. In recent decades, northern China has experienced
increased drought, and southern China has received increased summer rain
resulting in a larger number of floods. Southern China has had a
decrease in temperatures while most of the world has warmed. In a paper
with Menon and colleagues, through the use of observations and climate
models results, they conclude that the black carbon heats the air,
increases convection and precipitation, and leads to larger surface
cooling than if the aerosols were sulfates.
A year later, Hansen teamed with Makiko Sato to publish a study on black carbon using the global network of AERONET
sun photometers. While the location of the AERONET instruments did not
represent a global sample, they could still be used to validate global
aerosol climatologies. They found that most aerosol climatologies
underestimated the amount of black carbon by a factor of at least 2. This corresponds to an increase in the climate forcing of around 1 W/m2, which they hypothesize is partially offset by the cooling of non-absorbing aerosols.
Estimations of trends in black carbon emissions show that there was a rapid increase in the 1880s after the start of the Industrial Revolution,
and a leveling off from 1900–1950 as environmental laws were enacted.
China and India have recently increased their emissions of black carbon
corresponding to their rapid development.
The emissions from the United Kingdom were estimated using a network of
stations that measured black smoke and sulfur dioxide. They report that
atmospheric black carbon concentrations have been decreasing since the
beginning of the record in the 1960s, and that the decline was faster
than the decline in black-carbon-producing fuel use.
A 2007 paper used the GISS climate model in an attempt to
determine the origin of black carbon in the arctic. Much of the arctic
aerosol comes from south Asia. Countries such as the United States and
Russia have a lower contribution than previously assumed.
Anthropogenic impact on climate
Hansen
has warned that low-lying coastal areas such as Florida (seen here),
East Anglia, the Netherlands, oceanic islands and Bangladesh are
vulnerable to sea levels rising.
The United Nations Framework Convention on Climate Change
is an international environmental treaty that has the objective of
stabilizing greenhouse gas concentrations in the atmosphere at a level
that would prevent dangerous anthropogenic interference with the climate system.
In 2000, Hansen advanced an alternative view of global warming
over the last 100 years, arguing that during that time frame the
negative forcing via aerosols and the positive forcing via carbon
dioxide (CO
2) largely balanced each other out, and that the 0.74±0.18 °C net rise in average global temperatures could mostly be explained by greenhouse gases other than carbon dioxide, such as methane and chlorofluorocarbons. However, even then he wrote "the future balance of forcings is likely to shift toward dominance of CO2 over aerosols".
2) largely balanced each other out, and that the 0.74±0.18 °C net rise in average global temperatures could mostly be explained by greenhouse gases other than carbon dioxide, such as methane and chlorofluorocarbons. However, even then he wrote "the future balance of forcings is likely to shift toward dominance of CO2 over aerosols".
In 2003, Hansen wrote a paper called "Can We Defuse the Global
Warming Time Bomb?" in which he argued that human-caused forces on the
climate are now greater than natural ones, and that this, over a long
time period, can cause large climate changes.
He further stated that a lower limit on "dangerous anthropogenic
interference" was set by the stability of the Greenland and Antarctic ice sheets.
His view on actions to mitigate climate change was that "halting global
warming requires urgent, unprecedented international cooperation, but
the needed actions are feasible and have additional benefits for human
health, agriculture and the environment."
In a 2004 presentation at the University of Iowa, Hansen
announced that he was told by high-ranking government officials not to
talk about how anthropogenic influence could have a dangerous effect on
climate because it was not understood what 'dangerous' meant, or how
humans were actually affecting climate. He described this as a Faustian bargain
because atmospheric aerosols had health risks, and should be reduced,
but doing so would effectively increase the warming effects from CO
2.
2.
Hansen and coauthors proposed that the global mean temperature
was a good tool to diagnose dangerous anthropogenic interference with
the climate system. Two elements were identified as particularly
important when discussing dangerous anthropogenic interference: sea
level rise and the extinction of species. They described a
business-as-usual scenario, which has greenhouse gases growing at
approximately 2% per year; and an alternate scenario, in which
greenhouse gases concentrations decline. Under the alternate scenario,
sea levels could rise by 1 meter per century, causing problems due to
the dense population in coastal areas. But this would be minor compared
to the 10-meter increase in sea level under the business-as-usual
scenario. Hansen described the situation with species extinction
similarly to that of sea level rise. Assuming the alternate scenario,
the situation would not be good, but it would be much worse for business
as usual.
The concept of dangerous anthropogenic interference was clarified
in a 2007 paper, finding that further warming of 1 °C would be highly
disruptive to humans. An alternate scenario would keep the warming to
below this if climate sensitivity were below 3 °C for doubled CO
2. The conclusion was that CO
2 levels above 450 ppm were considered dangerous, but that reduction in non-CO
2 greenhouse gases could provide temporary relief from drastic CO
2 cuts. Further findings are that arctic climate change has been forced by non-CO
2 constituents as much as by CO
2. The 2007 paper cautioned that prompt action is needed to slow CO
2 growth and to prevent a dangerous anthropogenic interference.
2. The conclusion was that CO
2 levels above 450 ppm were considered dangerous, but that reduction in non-CO
2 greenhouse gases could provide temporary relief from drastic CO
2 cuts. Further findings are that arctic climate change has been forced by non-CO
2 constituents as much as by CO
2. The 2007 paper cautioned that prompt action is needed to slow CO
2 growth and to prevent a dangerous anthropogenic interference.
Climate model development and projections
A comparison of global surface temperature computed for three scenarios and compared with two analysis of observational data.
Vilhelm Bjerknes
began the modern development of the general circulation model in the
early 20th century. The progress of numerical modeling was slow due to
the slow speed of early computers and the lack of adequate observations.
It wasn't until the 1950s that the numerical models were getting close
to being realistic.
Hansen's first contribution to numerical climate models came with the
1974 publication of the GISS model. He and his colleagues claimed that
the model was successful in simulating the major features of sea-level
pressure and 500mb heights in the North American region.
A 1981 Science publication by Hansen and a team of
scientists at Goddard concluded that carbon dioxide in the atmosphere
would lead to warming sooner than previously predicted. They used a
one-dimensional radiative-convective model that calculates temperature
as a function of height. They reported that the results from the 1D
model are similar to those of the more complex 3D models, and can
simulate basic mechanisms and feedbacks.
Hansen predicted that temperatures would rise out of the climate noise
by the 1990s, much earlier than predicted by other researches. He also
predicted that it would be difficult to convince politicians and the
public to react.
By the early 1980s, the computational speed of computers, along
with refinements in climate models, allowed longer experiments. The
models now included physics beyond the previous equations, such as
convection schemes, diurnal changes, and snow-depth calculations. The
advances in computational efficiency, combined with the added physics,
meant the GISS model could be run for five years. It was shown that
global climate can be simulated reasonably well with a grid-point
resolution as coarse as 1000 kilometers.
The first climate prediction computed from a general circulation
model that was published by Hansen was in 1988, the same year as his
well-known Senate testimony. The second generation of the GISS model was used to estimate the change in mean surface temperature
based on a variety of scenarios of future greenhouse gas emissions.
Hansen concluded that global warming would be evident within the next
few decades, and that it would result in temperatures at least as high
as during the Eemian. He argued that if the temperature rose 0.4 °C above the 1950–1980 mean for a few years, it would be the "smoking gun" pointing to human-caused global warming.
Hansen giving testimony before the United States Congress in 1988.
In 2006, Hansen and colleagues compared the observations with the projections made by Hansen in his 1988 testimony before the United States Congress.
They described the intermediate scenario as the most likely, and that
real-world greenhouse gas forcing had been closest to this scenario. It
contained the effects of three volcanic eruptions in the fifty-year
projections, with one in 1995, whereas the recent Mount Pinatubo
eruption was in 1991. They found that the observed warming was similar
to two of the three scenarios. The warming rates of the two most modest
warming scenarios were nearly the same through the year 2000, and they
were unable to provide a precise model assessment. They did note that
the agreement between the observations and the intermediate scenario was
accidental because the climate sensitivity used was higher than current estimates.
A year later, Hansen joined with Rahmstorf
and colleagues comparing climate projections with observations. The
comparison was done from 1990 through January 2007 against physics-based
models that are independent from the observations after 1990. They
showed that the climate system may be responding faster than the models
indicate. Rahmstorf and coauthors showed concern that sea levels are rising at the high range of the IPCC projections, and that this was due to thermal expansion and not from melting of the Greenland or Antarctic ice sheets.
Following the launch of spacecraft capable of determining temperatures, Roy Spencer and John Christy published the first version of their satellite temperature measurements in 1990. Contrary to climate models and surface measurements, their results showed a cooling in the troposphere. However, in 1998, Wentz and Schabel determined that orbital decay had an effect on the derived temperatures.
Hansen compared the corrected troposphere temperatures with the results
of the published GISS model, and concluded that the model is in good
agreement with the observations, noting that the satellite temperature
data had been the last holdout of global warming denialists,
and that the correction of the data would result in a change from
discussing whether global warming is occurring to what is the rate of
global warming, and what should be done about it.
Hansen has continued the development and diagnostics of climate
models. For instance, he has helped in the investigations of the decadal
trends in tropopause height, which could be a useful tool for determining the human "fingerprint" on climate. As of 12 February 2009,
the current version of the GISS model is Model E. This version has seen
improvements in many areas, including upper-level winds, cloud height,
and precipitation. This model still has problems with regions of marine stratocumulus clouds. A later paper showed that the model's main problems are having too weak of an ENSO-like variability, and poor sea ice modeling, resulting in too little ice in the Southern Hemisphere and too much in the Northern Hemisphere.
Climate forcings, feedbacks, and sensitivity
Estimated climate forcings between 1850 and 2000
In 2000 Hansen authored a paper called "Global warming in the
twenty-first century: an alternative scenario" in which he presented a
more optimistic way of dealing with global warming, focusing on non-CO2 gases and black carbon in the short run, giving more time to make reductions in fossil fuel emissions. He notes that the net warming observed to date is roughly as big as that expected from non-CO2 gases only. This is because CO2 warming is offset by climate-cooling aerosols emitted with fossil fuel burning and because at that time non-CO2 gases, taken together, were responsible for roughly 50% of the anthropogenic greenhouse gas warming.
In a 2007 paper, Hansen discussed the potential danger of "fast-feedback" effects causing ice sheet disintegration, based on paleoclimate data. George Monbiot reports "The IPCC predicts that sea levels could rise by as much as 59 centimetres (1.94 ft) this century.
Hansen's paper argues that the slow melting of ice sheets the panel
expects doesn't fit the data. The geological record suggests that ice at
the poles does not melt in a gradual and linear fashion, but flips
suddenly from one state to another. When temperatures increased to 2–3°C
(3.6–5.4°F) above today's level 3.5 million years ago, sea levels rose
not by 59 centimeters but by 25 metres (82 ft). The ice responded
immediately to changes in temperature."
Hansen stressed the uncertainties around these predictions. "It
is difficult to predict time of collapse in such a nonlinear problem …
An ice sheet response time of centuries seems probable, and we cannot
rule out large changes on decadal time-scales once wide-scale surface
melt is underway."
He concludes that "present knowledge does not permit accurate
specification of the dangerous level of human-made [greehouse gases].
However, it is much lower than has commonly been assumed. If we have not
already passed the dangerous level, the energy infrastructure in place
ensures that we will pass it within several decades."
In 2013, Hansen authored a paper called "Climate sensitivity, sea
level and atmospheric carbon dioxide," in which he estimated climate
sensitivity to be (3±1) °C based on Pleistocene paleoclimate data. The paper also concluded that burning all fossil fuels "would make most of the planet uninhabitable by humans."
In 2016, a team of 19 researchers led by Hansen published a paper
"Ice melt, sea level rise and superstorms: evidence from paleoclimate
data, climate modeling, and modern observations that 2 °C global warming
could be dangerous" describing the effect of meltwater from ice sheets
on the Atlantic meridional overturning circulation (slowing it or even stopping) and Antarctic bottom water
formation. This would speed up ice sheet melting and sea level rise by
increasing the water temperature at hundreds of meters depth, thawing
ice shelves from below. And the cool fresh meltwater on the ocean close
to Greenland and Antarctica leads to larger temperature difference
between tropics and middle latitudes, what would enable storms as strong
as in the last interglacial, the Eemian, whose evidence includes, among others, megaboulders on Bahamas.
Analysis of climate change causation
The first action that people should take is to use the democratic process. What is frustrating people, me included, is that democratic action affects elections but what we get then from political leaders is greenwash.— James Hansen (March 2009)
Hansen noted that in determining responsibility for climate change,
the effect of greenhouse gas emissions on climate is determined not by
current emissions, but by accumulated emissions over the lifetime of
greenhouse gases in the atmosphere.
By this measure, the U.K. is still the largest single cause of
climate change, followed by the U.S. and Germany, even though its
current emissions are surpassed by the People's Republic of China.
On public policy, Hansen is critical of what he sees as efforts
to mislead the public on the issue of climate change. He points
specifically to the Competitive Enterprise Institute's commercials with the tagline "carbon dioxide—they call it pollution, we call it life", and politicians who accept money from fossil-fuel interests and then describe global warming as "a great hoax."
He also says that changes needed to reduce global warming do not
require hardship or reduction in the quality of life, but will also
produce benefits such as cleaner air and water, and growth of high-tech
industries. He was a critic of both the Clinton and George W. Bush Administrations' stances on climate change.
Addressing the potential effects of climate change, Hansen has stated
in an interview in January, 2009, "We cannot now afford to put off
change any longer. We have to get on a new path within this new
administration. We have only four years left for Obama to set an example
to the rest of the world. America must take the lead."
Climate change activism
US Senate committee testimony
Hansen was invited by Rafe Pomerance to testify before the United States Senate Committee on Energy and Natural Resources on June 23, 1988.
Hansen testified that "Global warming has reached a level such that we
can ascribe with a high degree of confidence a cause and effect
relationship between the greenhouse effect and observed warming...It is
already happening now"
and "The greenhouse effect has been detected and it is changing our
climate now...We already reached the point where the greenhouse effect
is important."
Hansen said that NASA was 99% confident that the warming was caused by
the accumulation of greenhouse gases in the atmosphere and not a random
fluctuation.
According to science historian Spencer R. Weart, Hansen's testimony increased public awareness of climate change. According to Richard Besel of California Polytechnic State University, Hansen's testimony "was an important turning point in the history of global climate change." According to Timothy M. O'Donnell of the University of Mary Washington,
Hansen's testimony was "pivotal," "ignited public discussion of global
warming and moved the controversy from a largely scientific discussion
to a full blown science policy debate," and marked "the official
beginning of the global warming policy debate." According to Roger A. Pielke of the National Center for Atmospheric Research,
Hansen's "call to action" "elevated the subject of global warming and
the specter of associated impacts such as more hurricanes, floods, and
heat waves, to unprecedented levels of attention from the public, media,
and policy makers."
Criticism of coal industry
Hansen has been particularly critical of the coal industry, stating that coal contributes the largest percentage of anthropogenic carbon dioxide into the atmosphere.
He acknowledges that a molecule of carbon dioxide emitted from burning
coal has the same effect as a molecule emitted from burning oil. The
difference is where the fuel originally resides. He says that most oil
comes from Russia and Saudi Arabia, and that no matter how fuel-efficient automobiles become, the oil will eventually be burned and the CO
2 emitted. In a 2007 testimony before the Iowa Utilities Board, he stated that the United States has a large reservoir of coal, which makes it a resource that can be controlled through action by U.S. politicians, unlike oil which is controlled by other countries. He has called for phasing out coal power completely by the year 2030.
2 emitted. In a 2007 testimony before the Iowa Utilities Board, he stated that the United States has a large reservoir of coal, which makes it a resource that can be controlled through action by U.S. politicians, unlike oil which is controlled by other countries. He has called for phasing out coal power completely by the year 2030.
During his testimony before the Iowa Utilities Board in 2007,
Hansen likened coal trains to "death trains" and asserted that these
would be "no less gruesome than if they were boxcars headed to
crematoria, loaded with uncountable irreplaceable species." In response, the National Mining Association stated that his comparison "trivialized the suffering of millions" and "undermined his credibility."
Citing the reactions of "several people" and "three of his scientific
colleagues" as his primary motivation, Hansen stated that he certainly
did not mean to trivialize suffering by the families who lost relatives
in the Holocaust and then apologized, saying he regretted that his words caused pain to some readers.
Mountaintop removal mining
On June 23, 2009, James Hansen, along with 30 other protesters including actress Daryl Hannah, was arrested on misdemeanor charges of obstructing police and impeding traffic, during a protest against mountaintop removal mining in Raleigh County, West Virginia. The protesters intended to enter the property of Massey Energy Company, but were blocked by a crowd of several hundred coal miners and supporters.
Hansen said that mountaintop removal for coal mining "[provides] only a
small fraction of our energy" and "should be abolished." Hansen called on President Barack Obama to abolish mountaintop coal mining.
Hansen and about 100 other people were arrested in September 2010 in front of the White House in Washington, DC. The group was seeking a ban on mountaintop removal or surface mining.
Cap and trade
In 2009 Hansen spoke out against cap and trade, advocating instead what he believes would be a progressive carbon tax at source carbon as oil, gas or coal, with a 100% dividend returned to citizens in equal shares, as proposed by Citizens' Climate Lobby. He has made many appearances and talks supporting the work of CCL.
Retirement from NASA
Hansen
retired from NASA in April 2013 after 46 years of government service,
saying he planned to take a more active role in the political and legal
efforts to limit greenhouse gases. The same month, the National Center for Science Education,
an organization noted for defending the teaching of evolution in United
States science classrooms, named Hansen as an advisor to support the
extension of its area of concern into the teaching of climate change.
Keystone Pipeline
In a CBC interview aired in April 2013, as Canadian Natural Resources Minister Joe Oliver lobbied in Washington, DC for approval of Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Oil Sands to the Gulf of Mexico, Hansen forcefully argued against the use of these unconventional fossil fuels. According to Intergovernmental Panel on Climate Change
(IPCC) and other energy organizations "there is more than twice as much
carbon in the tar sands oil" than in conventional oil. Hansen argued
that coal, tar sands, and tar shale should not be used as energy sources
because of their carbon emissions and claimed that the completion of
the Keystone pipeline would increase the extraction of oil from oil
sands. He explained that the effects of climate change may not be
apparent until the far future: "It's not the case where you emit
something and you see the effect. We see the beginnings of the effect
but the large impacts are going to be in future decades and that science
is crystal clear … Effects come slowly because of the inertia of the
climate system. It takes decades, even centuries to get the full
response. But we know the last time the world was 2 degrees warmer, sea
level was 6 meters or 20 feet higher." Hansen urged President Obama to reject the Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Oil Sands to the Gulf of Mexico. On February 13, 2013, Hansen was again arrested at the White House, along with Daryl Hannah and Robert F. Kennedy, Jr., during a further protest against the proposed Keystone pipeline extension.
Proposed solutions
Recently Hansen stated his support for a revenue-neutral fee and dividend
system to impose a price on carbon that returns the money collected
from the fossil fuel industry equally to all legal residents of the
United States. In an interview on CBC television on March 3, 2015, Dr
Hansen stated "The solution [to climate change] has to be a rising price
on carbon and then the really dirty fuels like tar sands would fall on
the table very quickly. They make no sense at all if you look at it from
an economic-wide perspective. If we would simply put a fee on carbon –
you would collect from the fossil fuel companies at the source (the
domestic mines or the ports of entry) and then distribute that money to
the public, an equal amount to all legal residents, that would begin to
make the prices honest. And that's what the economy needs in order to be
most efficient. Right now the external costs of fossil fuels are borne
completely by the public. If your child gets asthma, you pay the bill,
the fossil fuel company doesn't. What we need is to make the system
honest."
At the end of 2008, James Hansen stated five priorities that he
felt then President-elect Barack Obama should adopt "for solving the
climate and energy problems, while stimulating the economy": efficient energy use, renewable energy, a smart grid, generation IV nuclear reactors and carbon capture and storage. Regarding nuclear, he expressed opposition to the Yucca Mountain nuclear waste repository, stating that the $25 Billion (US) surplus held in the Nuclear Waste Fund "should be used to develop fast reactors that consume nuclear waste, and thorium reactors to prevent the creation of new long-lived nuclear waste."
In 2009, Hansen wrote an open letter to President Obama where he advocated a "Moratorium and phase-out of coal plants that do not capture and store CO2". In his first book Storms of My Grandchildren, similarly, Hansen discusses his Declaration of Stewardship,
the first principle of which requires "a moratorium on coal-fired power
plants that do not capture and sequester carbon dioxide".
In March 2013, Hansen co-authored a paper in Environmental Science & Technology,
entitled "Prevented mortality and greenhouse gas emissions from
historical and projected nuclear power". The paper examined mortality
rates per unit of electrical power produced from fossil fuels (coal and natural gas) as well as nuclear power.
It estimated that 1.8 million air pollution-caused deaths were
prevented worldwide between 1971 and 2009, through the use of nuclear
power instead of fossil fuels. The paper also concluded that the
emission of some 64 billion tonnes of carbon dioxide equivalent were
avoided by nuclear power use between 1971 and 2009. Looking to the
future, between 2010 and 2050, it was estimated that nuclear could
additionally avoid up to 420,000 to 7 million premature deaths and 80 to
240 billion tonnes of greenhouse gas emissions.
This paper elicited a critical response to Kharecha and Hansen's
analysis, from an international group of senior academic energy policy
analysts, including Benjamin Sovacool, M.V. Ramana, Mark Z. Jacobson, and Mark Diesendorf.
They asserted that nuclear power needs large subsidies to be
economically viable, and typically there are substantial construction
delays and cost overruns associated with nuclear plants. Sovacool et al.
also claim that Kharecha and Hansen's estimates of Chernobyl Disaster
mortalities is very low, which biases their conclusions. All of these
factors are said to make Kharecha and Hansen's article "incomplete and
misleading". Kharecha and Hansen countered that all the data these scientists use to make their criticism, "lacks credibility".
In 2013, Hansen and three other leading climate experts wrote an
open letter to policy makers, saying that "continued opposition to
nuclear power threatens humanity's ability to avoid dangerous climate
change." The reaction from anti-nuclear environmental groups (e.g. the Natural Resources Defense Council, Sierra Club, and Greenpeace) was negative, citing nuclear safety and security issues, and the economics of nuclear power plants.
Honors and awards
Hansen was elected to the National Academy of Sciences
in 1996 for his "development of pioneering radiative transfer models
and studies of planetary atmospheres; development of simplified and
three-dimensional global climate models; explication of climate forcing
mechanisms; analysis of current climate trends from observational data;
and projections of anthropogenic impacts on the global climate system." In 2001, he received the 7th Annual Heinz Award in the Environment (endowed with US$250,000) for his research on global warming, and was listed as one of Time Magazine's 100 Most Influential People in 2006. Also in 2006, the American Association for the Advancement of Science (AAAS) selected James Hansen to receive its Award for Scientific Freedom and Responsibility
"for his courageous and steadfast advocacy in support of scientists'
responsibilities to communicate their scientific opinions and findings
openly and honestly on matters of public importance."
In 2007, Hansen shared the US $1-million Dan David Prize
for "achievements having an outstanding scientific, technological,
cultural or social impact on our world". In 2008, he received the PNC Bank Common Wealth Award of Distinguished Service for his "outstanding achievements" in science. At the end of 2008, Hansen was named by EarthSky Communications and a panel of 600 scientist-advisors as the Scientist Communicator of the Year,
citing him as an "outspoken authority on climate change" who had "best
communicated with the public about vital science issues or concepts
during 2008."
In 2009, Hansen was awarded the 2009 Carl-Gustaf Rossby Research Medal, the highest honor bestowed by the American Meteorological Society,
for his "outstanding contributions to climate modeling, understanding
climate change forcings and sensitivity, and for clear communication of
climate science in the public arena."
Hansen won the 2010 Sophie Prize, set up in 1997 by Norwegian Jostein Gaarder, the author of the 1991 best-selling novel and teenagers' guide to philosophy Sophie's World, for his " key role for the development of our understanding of human-induced climate change."
Foreign Policy named Hansen one of its 2012 FP Top 100 Global Thinkers "for sounding the alarm on climate change, early and often".
In December 2012, Hansen received the Commonwealth Club of California's annual Stephen H. Schneider Award for Outstanding Climate Science Communications at a ceremony in San Francisco.
On November 7, 2013 Hansen received the Joseph Priestley Award at Dickinson College
in Carlisle, Pennsylvania "...for his work advancing our understanding
of climate change, including the early application of numerical models
to better understand observed climate trends and to project humans'
impact on climate, and for his leadership in promoting public
understanding of climate and linking the knowledge to action on climate
policy." He delivered a lecture, entitled, "White House Arrest and the
Climate Crisis," later that same day at Anita Tuvin Schlechter
Auditorium on the college's campus.
James Hansen was co-winner with climatologist Syukuro Manabe of the BBVA Foundation Frontiers of Knowledge Award
in the Climate Change category in the ninth edition (2016) of the
awards. The two laureates were separately responsible for constructing
the first computational models with the power to simulate climate
behavior. Decades ago, they correctly predicted how much Earth's
temperature would rise due to increasing atmospheric CO2. The scores of
models currently in use to chart climate evolution are heirs to those
developed by Manabe and Hansen.
In June 2018, Hansen was named joint winner, with Veerabhadran Ramanathan, of Taiwan's Tang Prize. Hansen's prize had a total value of NT$25 million.
Controversies
Political interference at NASA
In 2006, Hansen alleged that NASA administrators had attempted to influence his public statements about the causes of climate change.
Hansen said that NASA public relations staff were ordered to review his
public statements and interviews after a December 2005 lecture at the American Geophysical Union in San Francisco.
NASA responded that its policies are similar to those of any other
federal agency in requiring employees to coordinate all statements with
the public affairs office without exception.
Two years after Hansen and other agency employees described a pattern
of distortion and suppression of climate science by political appointees,
the agency's inspector general confirmed that such activities had taken
place, with the NASA Office of Public Affairs having "reduced,
marginalized or mischaracterized climate change science made available
to the general public".
In June 2006, Hansen appeared on 60 Minutes
stating that the George W. Bush White House had edited climate-related
press releases reported by federal agencies to make global warming seem
less threatening.
He also stated that he was unable to speak freely without the backlash
of other government officials, and that he had not experienced that
level of restrictions on communicating with the public during his
career.
Trials for energy company executives
In 2008 interviews with ABC News, The Guardian, and in a separate op-ed, Hansen has called for putting fossil fuel company executives, including the CEOs of ExxonMobil and Peabody Coal, on trial for "high crimes
against humanity and nature", on the grounds that these and other
fossil-fuel companies had actively spread doubt and misinformation about
global warming, in the same way that tobacco companies tried to hide the link between smoking and cancer.
Arrest for protest demonstration
James Hansen arrested at a demonstration outside the White House, August 29, 2011
Hansen
and 1251 other activists were arrested in August and September 2011, at
another demonstration in front of the White House. Hansen urged
President Obama to reject the Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Tar Sands to the Gulf of Mexico. On February 13, 2013, Hansen was again arrested at the White House, along with Daryl Hannah and Robert F. Kennedy, Jr., during a further protest against the proposed Keystone pipeline extension.
Criticism
In January 2009, Andrew Freedman wrote in The Washington Post, that the American Meteorological Society had erred in giving Hansen its Carl-Gustaf Rossby Research Medal:
"His body of work is not at issue... Rather, the problem arises due to
the AMS' recognition of Hansen's public communication work on climate
change." Former AMS member Joseph D'Aleo, a skeptic of human-caused climate change, also criticized the award.
Also in 2009, physicist Freeman Dyson
criticised Hansen's climate-change activism. "The person who is really
responsible for this overestimate of global warming is Jim Hansen. He
consistently exaggerates all the dangers... Hansen has turned his
science into ideology."
Hansen responded that if Dyson "is going to wander into something with
major consequences for humanity and other life on the planet, then he
should first do his homework". Dyson stated in an interview that the argument with Hansen was exaggerated by The New York Times, stating that he and Hansen are "friends, but we don't agree on everything."
After Hansen's arrest in 2009 in West Virginia, New York Times columnist Andrew Revkin
wrote: "Dr. Hansen has pushed far beyond the boundaries of the
conventional role of scientists, particularly government scientists, in
the environmental policy debate."
In June 2009, New Yorker journalist Elizabeth Kolbert wrote that Hansen is "increasingly isolated among climate activists." Eileen Claussen, president of the Pew Center on Global Climate Change,
said that "I view Jim Hansen as heroic as a scientist.... But I wish he
would stick to what he really knows. Because I don't think he has a
realistic idea of what is politically possible, or what the best
policies would be to deal with this problem."
In July 2009, New York Times climate columnist Christa
Marshall asked if Hansen still matters in the ongoing climate debate,
noting that he "has irked many longtime supporters with his scathing
attacks against President Obama's plan for a cap-and-trade system." "The right wing loves what he's doing," said Joseph Romm, a senior fellow at the Center for American Progress, a liberal think tank.
Hansen said that he had to speak out, since few others could explain
the links between politics and the climate models. "You just have to say
what you think is right," he said.
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