Environmental chemistry

From Wikipedia, the free encyclopedia

White bags filled with contaminated stones line the shore near an industrial oil spill in Raahe, Finland

Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity and biological activity on these. Environmental chemistry is an interdisciplinary science that includes atmospheric, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to environmental and other areas of science.

Environmental chemistry is the study of chemical processes occurring in the environment which are impacted by humankind's activities. These impacts may be felt on a local scale, through the presence of urban air pollutants or toxic substances arising from a chemical waste site, or on a global scale, through depletion of stratospheric ozone or global warming. The focus in our courses and research activities is upon developing a fundamental understanding of the nature of these chemical processes, so that humankind's activities can be accurately evaluated.

Environmental chemistry involves first understanding how the uncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on the environment through the release of chemicals.

Environmental chemists draw on a range of concepts from chemistry and various environmental sciences to assist in their study of what is happening to a chemical species in the environment. Important general concepts from chemistry include understanding chemical reactions and equations, solutions, units, sampling, and analytical techniques.^[1]

Contamination

A contaminant is a substance present in nature at a level higher than typical levels or that would not otherwise be there.^[2][3] This may be due to human activity. The term contaminant is often used interchangeably with pollutant, which is a substance that has a detrimental impact on the surrounding environment.^[4][5] Whilst a contaminant is sometimes defined as a substance present in the environment as a result of human activity, but without harmful effects, it is sometimes the case that toxic or harmful effects from contamination only become apparent at a later date.^[6]
The "medium" (e.g. soil) or organism (e.g. fish) affected by the pollutant or contaminant is called a receptor, whilst a sink is a chemical medium or species that retains and interacts with the pollutant.

Environmental indicators

Chemical measures of water quality include dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), pH, nutrients (nitrates and phosphorus), heavy metals (including copper, zinc, cadmium, lead and mercury), and pesticides.

Applications

Environmental chemistry is used by the Environment Agency (in England and Wales), the Environmental Protection Agency (in the United States) the Association of Public Analysts, and other environmental agencies and research bodies around the world to detect and identify the nature and source of pollutants. These can include:

• Heavy metal contamination of land by industry. These can then be transported into water bodies and be taken up by living organisms.
• Nutrients leaching from agricultural land into water courses, which can lead to algal blooms and eutrophication.^[7]
• Urban runoff of pollutants washing off impervious surfaces (roads, parking lots, and rooftops) during rain storms. Typical pollutants include gasoline, motor oil and other hydrocarbon compounds, metals, nutrients and sediment (soil).^[8]
• Organometallic compounds.^[9]

Methods

Quantitative chemical analysis is a key part of environmental chemistry, since it provides the data that frame most environmental studies.^[10]

Common analytical techniques used for quantitative determinations in environmental chemistry include classical wet chemistry, such as gravimetric, titrimetric and electrochemical methods. More sophisticated approaches are used in the determination of trace metals and organic compounds. Metals are commonly measured by atomic spectroscopy and mass spectrometry: Atomic Absorption Spectrophotometry (AAS) and Inductively Coupled Plasma Atomic Emission (ICP-AES) or Inductively Coupled Plasma Mass Spectrometric (ICP-MS) techniques. Organic compounds are commonly measured also using mass spectrometric methods, such as Gas chromatography-mass spectrometry (GC/MS) and Liquid chromatography-mass spectrometry (LC/MS). Non-MS methods using GCs and LCs having universal or specific detectors are still staples in the arsenal of available analytical tools.

Other parameters often measured in environmental chemistry are radiochemicals. These are pollutants which emit radioactive materials, such as alpha and beta particles, posing danger to human health and the environment. Particle counters and Scintillation counters are most commonly used for these measurements. Bioassays and immunoassays are utilized for toxicity evaluations of chemical effects on various organisms.

Published analytical methods

Peer-reviewed test methods have been published by government agencies^[11][12] and private research organizations.^[13] Approved published methods must be used when testing to demonstrate compliance with regulatory requirements.

Avoiding dangerous climate change

From Wikipedia, the free encyclopedia

Avoiding dangerous climate change (also expressed with equivalent terms such as preventing dangerous anthropogenic interference with the climate system) is a major objective of both scientific research and in international governmental development of climate policy.
The concept expressed by these phrases was central to the "IPCC Second Assessment: Climate Change 1995" published by the International Panel on Climate Change.^[1] In 2002, the United Nations Framework Convention on Climate Change (UNFCCC),^[2] an international organization established by treaty in 1992, incorporated the concept as the focus of its formal Framework Convention policy:

"ARTICLE 2. OBJECTIVE. The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner." (Emph. added)^[3]

Avoiding dangerous climate change and its equivalent terms have continued in common usage in the policy community,^[4][5] scientific literature^[6][7] and news media,^[8][9][10] and in 2005 a scientific conference (see below) focused on the concept and used the phrase in its title. The problem that arises is to decide what level of interference would lead to "dangerous" change.^[11] The relevance of the issue is increasing as existing Earth System Models project that as early as 2020 in tropical areas, 2047 on average globally, the Earth's surface temperature could move beyond historical analogs, potentially impacting over 3 billion people and the most diverse places on Earth.^[12]

Setting temperature rise goals

Limiting the average global surface temperature increase of 2°C (3.6°F) over the pre-industrial average has, since the 1990s, been commonly regarded as an adequate means of avoiding dangerous climate change, in science and policy making.^[13][14] However, recent science has shown that the weather, environmental and social impacts of 2°C rise are much greater than the earlier science indicated, and that impacts for a 1°C rise are now expected to be as great as those previously assumed for a 2°C rise.^[11] In a July 2011 speech, climate scientist Kevin Anderson explained that for this reason, avoiding dangerous climate in the conventional sense is no longer possible, because the temperature rise is already close to 1°C, with effects formerly assumed for 2°C.^[15][16] Moreover, Anderson's presentation demonstrates reasons why a temperature rise of 4°C by 2060 is a likely outcome, given the record to date of action on climate, economic realities, and short window of time remaining for limiting the average surface temperature rise to 2°C or even 3°C.^[15] He also states that a 4°C rise would likely be an unstable state, leading to further increases in following decades regardless of mitigation measures that may be taken.^[15]

The consequences of failing to avoid dangerous climate change have been explored in two recent scientific conferences: the 4 degrees and beyond climate change conference held at Oxford University in 2009; and the Four Degrees Or More? Australia in a Hot World held at the University of Melbourne in July 2011.

Symposium on avoiding dangerous climate change

In 2005 an international conference called "Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases"^[17] examined the link between atmospheric greenhouse gas concentration, and the 2 °C (3.6 °F) ceiling on global warming thought necessary to avoid the most serious effects of global warming. Previously, this had generally been accepted as being 550 ppm^[18]

The conference took place under the United Kingdom's presidency of the G8, with the participation of around 200 'internationally renowned' scientists from 30 countries. It was chaired by Dennis Tirpak and hosted by the Hadley Centre for Climate Prediction and Research in Exeter, from 1 February to 3 February.^[19]

Objectives

Global carbon dioxide emissions through year 2004

Global average surface temperature 1880 to 2009, with zero point set at the average temperature between 1961 and 1990.

The conference was called to bring together the latest research into what would be necessary to achieve the objective of the 1992 United Nations Framework Convention on Climate Change:

to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.

It was also intended to encourage further research in the area. An initial assessment of the subject had been included in the 2001 IPCC Third Assessment Report; however, the topic had received relatively little international discussion.^[20]

Specifically, the conference explored three issues:

• For different levels of climate change what are the key impacts, for different regions and sectors and for the world as a whole?
• What would such levels of climate change imply in terms of greenhouse gas stabilisation concentrations and emission pathways required to achieve such levels?
• What options are there for achieving stabilisation of greenhouse gases at different stabilisation concentrations in the atmosphere, taking into account costs and uncertainties?^[21]

The symposium's conclusions

Among the conclusions reached, the most significant was a new assessment of the link between the concentration of greenhouse gases in the atmosphere and the increase in global temperature levels. Some researchers have argued that the most serious consequences of global warming might be avoided if global average temperatures rose by no more than 2 °C (3.6 °F) above pre-industrial levels (1.4 °C above present levels). It had generally been assumed that this would occur if greenhouse gas concentrations rose above 550 ppm carbon dioxide equivalent by volume. This concentration was, for example, informing government in certain countries, including the European Union.^[22]

The conference concluded that, at the level of 550 ppm, it was likely that 2 °C would be exceeded, according to the projections of more recent climate models. Stabilising greenhouse gas concentrations at 450 ppm would only result in a 50% likelihood of limiting global warming to 2 °C, and that it would be necessary to achieve stabilisation below 400 ppm to give a relatively high certainty of not exceeding 2 °C.^[23]

The conference also claimed that, if action to reduce emissions is delayed by 20 years, rates of emission reduction may need to be 3 to 7 times greater to meet the same temperature target.^[23]

Proceedings of the symposium were published in 2011, in an open-access special issue of the Royal Society's Philosophical Transactions A.^[24]

Reactions to the symposium

As a result of changing opinion on the "safe" atmospheric concentration of greenhouse gases, to which this conference contributed, the UK Government changed the target in the Climate Change Act from 60% to 80% by 2050.^{[25][not in citation given]}

Carbon footprint

From Wikipedia, the free encyclopedia

The carbon footprint explained in a nutshell

A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person."^[1]

The total carbon footprint cannot be calculated because of the large amount of data required and the fact that carbon dioxide can be produced by natural occurrences. It is for this reason that Wright, Kemp, and Williams, writing in the journal Carbon Management, have suggested a more practicable definition:

A measure of the total amount of carbon dioxide (CO₂) and methane (CH₄) emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest. Calculated as carbon dioxide equivalent (CO₂e) using the relevant 100-year global warming potential (GWP100).^[2]

Greenhouse gases (GHGs) can be emitted through transport, land clearance, and the production and consumption of food, fuels, manufactured goods, materials, wood, roads, buildings, and services.^[3] For simplicity of reporting, it is often expressed in terms of the amount of carbon dioxide, or its equivalent of other GHGs, emitted.

Most of the carbon footprint emissions for the average U.S. household come from "indirect" sources, i.e. fuel burned to produce goods far away from the final consumer. These are distinguished from emissions which come from burning fuel directly in one's car or stove, commonly referred to as "direct" sources of the consumer's carbon footprint.^[4]

The concept name of the carbon footprint originates from ecological footprint, discussion,^[5] which was developed by Rees and Wackernagel in the 1990s which estimates the number of "earths" that would theoretically be required if everyone on the planet consumed resources at the same level as the person calculating their ecological footprint. However, given that ecological footprints are a measure of failure, Anindita Mitra (CREA, Seattle) chose the more easily calculated "carbon footprint" to easily measure use of carbon, as an indicator of unsustainable energy use. In 2007, carbon footprints was used as a measure of carbon emissions to develop the energy plan for City of Lynnwood, Washington. Carbon footprints are much more specific than ecological footprints since they measure direct emissions of gases that cause climate change into the atmosphere.

Measuring carbon footprints

An individual's, nation's, or organization's carbon footprint can be measured by undertaking a GHG emissions assessment or other calculative activities denoted as carbon accounting. Once the size of a carbon footprint is known, a strategy can be devised to reduce it, e.g. by technological developments, better process and product management, changed Green Public or Private Procurement (GPP), carbon capture, consumption strategies, carbon offsetting and others.

Several free online carbon footprint calculators exist,^[6][7] including a few supported by publicly available peer-reviewed data and calculations including the University of California, Berkeley's CoolClimate Network research consortium and CarbonStory.^[8][9][10] These websites ask you to answer more or less detailed questions about your diet, transportation choices, home size, shopping and recreational activities, usage of electricity, heating, and heavy appliances such as dryers and refrigerators, and so on. The website then estimates your carbon footprint based on your answers to these questions. A systematic literature review was conducted to objectively determine the best way to calculate individual/household carbon footprints. This review identified 13 calculation principles and subsequently used the same principles to evaluate the 15 most popular online carbon footprint calculators. The research documented significant shortcomings of a majority of the calculators.^[11]

The mitigation of carbon footprints through the development of alternative projects, such as solar or wind energy or reforestation, represents one way of reducing a carbon footprint and is often known as carbon offsetting.

The main influences on carbon footprints include population, economic output, and energy and carbon intensity of the economy.^[12] These factors are the main targets of individuals and businesses in order to decrease carbon footprints. Scholars suggest the most effective way to decrease a carbon footprint is to either decrease the amount of energy needed for production or to decrease the dependence on carbon emitting fuels.^[12]

Average carbon emissions per person by country

The Average Carbon Footprint in the United States vs. World The average U.S. household carbon footprint is about 50 tons CO₂ per year. The single largest source of emissions for the typical household is from driving (gasoline use). Transportation as a whole (driving, flying & small amount from public transit) is the largest overall category, followed by housing (electricity, natural gas, waste, construction) then food (mostly from red meat, dairy and seafood products, but also includes emissions from all other food), then goods followed lastly by services. The carbon footprint of U.S. households is about 5 times greater than the global average, which is approximately 10 tons CO₂ per household per year. For most U.S. households, the single most important action to reduce their carbon footprint is driving less or switching to a more efficient vehicle.^[13]

Direct carbon emissions

The Carbon footprint of energy

The following table compares, from peer-reviewed studies of full life cycle emissions and from various other studies, the carbon footprint of various forms of energy generation: nuclear, hydro, coal, gas, solar cell, peat and wind generation technology.

The Vattenfall study found renewable and nuclear generation responsible for far less CO₂ than fossil fuel generation.

− − − − −

Emission factors of common fuels

Fuel/ Resource	Thermal g(CO2-eq)/MJth Grams of CO2equivalent per Megajoule of thermal energy	Energy Intensity W·hth/W·he	Electric g(CO2-eq)/kW·he Grams of CO2equivalent per Kilowatt-hour of electrical energy
Coal	7001925100000000000B:91.50–91.72 Br:94.33 88	7000299000000000000B:2.62–2.85[14] Br:3.46[14] 3.01 −	7002994000000000000B:863–941[14] Br:1,175[14] 955[15] −
Oil −	700173000000000000073[16] −	70003400000000000003.40 −	7002893000000000000893[15] −
Natural gas −	7001683000000000000cc:68.20 oc:68.4 −	−	7002664000000000000cc:577[14] oc:751[14] 599[15] −
Geothermal Power −	70003000000000000003~ −	−	7001410000000000000TL0–1[15] TH91–122[15] −
Uranium Nuclear power −	−	6999190000000000000WL0.18[14] WH0.20[14] −	7001625000000000000WL60[14] WH65[14] −
Hydroelectricity (run of river) −	−	69984600000000000000.046[14]	700115000000000000015[14]
Conc. Solar Pwr			700140000000000000040±15#
Photovoltaics		69993300000000000000.33[14]	7002106000000000000106[14]
Wind power		69986600000000000000.066[14]	700121000000000000021[14]

Note: 3.6 MJ = megajoule(s) == 1 kW·h = kilowatt-hour(s), thus 1 g/MJ = 3.6 g/kW·h.
Legend: B = Black coal (supercritical)–(new subcritical), Br = Brown coal (new subcritical), cc = combined cycle, oc = open cycle, T_L = low-temperature/closed-circuit (geothermal doublet), T_H = high-temperature/open-circuit, W_L = Light Water Reactors, W_H = Heavy Water Reactors, #Educated estimate.

These three studies thus concluded that hydroelectric, wind, and nuclear power produced the least CO₂ per kilowatt-hour of any other electricity sources. These figures do not allow for emissions due to accidents or terrorism. Wind power and solar power, emit no carbon from the operation, but do leave a footprint during construction phase and maintenance during operation. Hydropower from reservoirs also has large footprints from initial removal of vegetation and ongoing methane (stream detritus decays anaerobically to methane in bottom of reservoir, rather than aerobically to CO₂ if it had stayed in an unrestricted stream).^[17]

The table above gives the carbon footprint per kilowatt-hour of electricity generated, which is about half the world's man-made CO₂ output. The CO₂ footprint for heat is equally significant and research shows that using waste heat from power generation in combined heat and power district heating, chp/dh has the lowest carbon footprint,^[18] much lower than micro-power or heat pumps.

Passenger transport

Average carbon dioxide emissions (grams) per passenger mile (USA). Based on 'Updated Comparison of Energy Use & CO2 Emissions From Different Transportation Modes, October 2008' (Manchester, NH: M.J. Bradley & Associates, 2008), p. 4, table 1.1 (http://www.buses.org/files/2008ABAFoundationComparativeFuelCO2.pdf).

This section gives representative figures for the carbon footprint of the fuel burned by different transport types (not including the carbon footprints of the vehicles or related infrastructure themselves). The precise figures vary according to a wide range of factors.

Flight

Some representative figures for CO₂ emissions are provided by LIPASTO's survey of average direct emissions (not accounting for high-altitude radiative effects) of airliners expressed as CO₂ and CO₂ equivalent per passenger kilometre:^[19]

• Domestic, short distance, less than 463 km (288 mi): 257 g/km CO₂ or 259 g/km (14.7 oz/mile) CO₂e
• Long distance flights: 113 g/km CO₂ or 114 g/km (6.5 oz/mile) CO₂e

Road

Some representative figures for CO₂ equivalent per passenger kilometre for road travel are provided by the Finnish survey LIPASTO (for 2011):^[20]

• Average for car travel: 98 g/km CO₂
• Average for urban bus travel: 58 g/km CO₂
• Average for highway coach travel: 49 g/km CO₂

Rail

In 2005, the US company Amtrak's carbon dioxide equivalent emissions per passenger kilometre were 0.116 kg,^[21] about twice as high as the UK rail average (where much more of the system is electrified),^[22] and about eight times a Finnish electric intercity train.^[23]

Sea

Average carbon dioxide emissions by ferries per passenger-kilometre seem to be 0.12 kg (4.2 oz).^[24] However, 18-knot ferries between Finland and Sweden produce 0.221 kg (7.8 oz) of CO₂, with total emissions equalling a CO₂ equivalent of 0.223 kg (7.9 oz), while 24–27-knot ferries between Finland and Estonia produce 0.396 kg (14.0 oz) of CO₂ with total emissions equalling a CO₂ equivalent of 0.4 kg (14 oz).^[25]

Indirect carbon emissions: the carbon footprints of products

Several organizations offer footprint calculators for public and corporate use,^[6] and several organizations have calculated carbon footprints of products.^[26] The US Environmental Protection Agency has addressed paper, plastic (candy wrappers), glass, cans, computers, carpet and tires. Australia has addressed lumber and other building materials. Academics in Australia, Korea and the US have addressed paved roads. Companies, nonprofits and academics have addressed mailing letters and packages. Carnegie Mellon University has estimated the CO₂ footprints of 46 large sectors of the economy in each of eight countries. Carnegie Mellon, Sweden and the Carbon Trust have addressed foods at home and in restaurants.

The Carbon Trust has worked with UK manufacturers on foods, shirts and detergents, introducing a CO₂ label in March 2007. The label is intended to comply with a new British Publicly Available Specification (i.e. not a standard), PAS 2050,^[27] and is being actively piloted by The Carbon Trust and various industrial partners.^[28] As of August 2012 The Carbon Trust state they have measured 27,000 certifiable product carbon footprints.^[29]

Evaluating the package of some products is key to figuring out the carbon footprint.^[30] The key way to determine a carbon footprint is to look at the materials used to make the item. For example, a juice carton is made of an aseptic carton, a beer can is made of aluminum, and some water bottles either made of glass or plastic. The larger the size, the larger the footprint will be.

Food

In a 2014 study by Scarborough et al., the real-life diets of British people were surveyed and their greenhouse gas footprints estimated.^[31] Average greenhouse-gas emissions per day (in kilograms of carbon dioxide equivalent) were:

• 7.19 for high meat-eaters
• 5.63 for medium meat-eaters
• 4.67 for low meat-eaters
• 3.91 for fish-eaters
• 3.81 for vegetarians
• 2.89 for vegans

Textiles

The precise carbon footprint of different textiles varies considerably according to a wide range of factors. However, studies of textile production in Europe suggest the following carbon dioxide equivalent emissions footprints per kilo of texile at the point of purchase by a consumer:^[32]

• Cotton: 7
• Nylon: 5.43
• PET (e.g. synthetic fleece): 5.55
• Wool: 5.48

Accounting for durability and energy required to wash and dry textile products, synthetic fabrics generally have a substantially lower carbon footprint than natural ones.^[33]

Materials

The carbon footprint of materials (also known as embodied carbon) varies widely. The carbon footprint of many common materials can be found in the Inventory of Carbon & Energy database.^[34]

Cement

Cement production and carbon footprint resulting from soil sealing was 8.0 Mg person⁻¹ of total per capita CO₂ emissions (Italy, year 2003); the balance between C loss due to soil sealing and C stocked in man-made infrastructures resulted in a net loss to the atmosphere, -0.6 Mg C ha⁻¹ y⁻¹.^[35]

Nuclear energy and carbon footprint

Most of the energy made for everyday use is from fossil fuels and as it is common knowledge fossil fuels create a very large carbon footprint, which leads us to the next fast solution; getting energy from nuclear power and reactors. But the most common nuclear reactor is uranium which causes a lot of global warming and carbon dioxide which doesn't help the reduction of carbon footprint; but thorium is a more efficient way to use nuclear power. Thorium is a safer, cleaner and more abundant alternative fuel; it produces about a thousand times less waste throughout the supply chain than uranium. So as you can imagine thorium had a considerably smaller carbon footprint that uranium.^[36]

Schemes to reduce carbon emissions: Kyoto Protocol, carbon offsetting, and certificates

Carbon dioxide emissions into the atmosphere, and the emissions of other GHGs, are often associated with the burning of fossil fuels, like natural gas, crude oil and coal. While this is harmful to the environment, carbon offsets can be purchased in an attempt to make up for these harmful effects.
The Kyoto Protocol defines legally binding targets and timetables for cutting the GHG emissions of industrialized countries that ratified the Kyoto Protocol. Accordingly, from an economic or market perspective, one has to distinguish between a mandatory market and a voluntary market. Typical for both markets is the trade with emission certificates:

• Certified Emission Reduction (CER)
• Emission Reduction Unit (ERU)
• Verified Emission Reduction (VER)

Mandatory market mechanisms

To reach the goals defined in the Kyoto Protocol, with the least economical costs, the following flexible mechanisms were introduced for the mandatory market:

• Clean Development Mechanism (CDM)
• Joint Implementation (JI)
• Emissions trading

The CDM and JI mechanisms requirements for projects which create a supply of emission reduction instruments, while Emissions Trading allows those instruments to be sold on international markets.

- Projects which are compliant with the requirements of the CDM mechanism generate Certified Emissions Reductions (CERs).

- Projects which are compliant with the requirements of the JI mechanism generate Emission Reduction Units (ERUs).

The CERs and ERUs can then be sold through Emissions Trading. The demand for the CERs and ERUs being traded is driven by:

- Shortfalls in national emission reduction obligations under the Kyoto Protocol.

- Shortfalls amongst entities obligated under local emissions reduction schemes.

Nations which have failed to deliver their Kyoto emissions reductions obligations can enter Emissions Trading to purchase CERs and ERUs to cover their treaty shortfalls. Nations and groups of nations can also create local emission reduction schemes which place mandatory carbon dioxide emission targets on entities within their national boundaries. If the rules of a scheme allow, the obligated entities may be able to cover all or some of any reduction shortfalls by purchasing CERs and ERUs through Emissions Trading. While local emissions reduction schemes have no status under the Kyoto Protocol itself, they play a prominent role in creating the demand for CERs and ERUs, stimulating Emissions Trading and setting a market price for emissions.

A well-known mandatory local emissions trading scheme is the EU Emissions Trading Scheme (EU ETS).

New changes are being made to the trading schemes. The EU Emissions Trading Scheme is set to make some new changes within the next year. The new changes will target the emissions produced by flight travel in and out of the European Union.^[37]

Other nations are scheduled to start participating in Emissions Trading Schemes within the next few year. These nations include China, India and the United States.^[37]

Voluntary Market Mechanisms

In contrast to the strict rules set out for the mandatory market, the voluntary market provides companies with different options to acquire emissions reductions. A solution, comparable with those developed for the mandatory market, has been developed for the voluntary market, the Verified Emission Reductions (VER). This measure has the great advantage that the projects/activities are managed according to the quality standards set out for CDM/JI projects but the certificates provided are not registered by the governments of the host countries or the Executive Board of the UNO. As such, high quality VERs can be acquired at lower costs for the same project quality. However, at present VERs can not be used in the mandatory market.

The voluntary market in North America is divided between members of the Chicago Climate Exchange and the Over The Counter (OTC) market. The Chicago Climate Exchange is a voluntary yet legally binding cap-and-trade emission scheme whereby members commit to the capped emission reductions and must purchase allowances from other members or offset excess emissions. The OTC market does not involve a legally binding scheme and a wide array of buyers from the public and private spheres, as well as special events that want to go carbon neutral. Being carbon neutral refers to achieving net zero carbon emissions by balancing a measured amount of carbon released with an equivalent amount sequestered or offset, or buying enough carbon credits to make up the difference.

There are project developers, wholesalers, brokers, and retailers, as well as carbon funds, in the voluntary market. Some businesses and nonprofits in the voluntary market encompass more than just one of the activities listed above. A report by Ecosystem Marketplace shows that carbon offset prices increase as it moves along the supply chain—from project developer to retailer.^[38]

While some mandatory emission reduction schemes exclude forest projects, these projects flourish in the voluntary markets. A major criticism concerns the imprecise nature of GHG sequestration quantification methodologies for forestry projects. However, others note the community co-benefits that forestry projects foster. Project types in the voluntary market range from avoided deforestation, afforestation/reforestation, industrial gas sequestration, increased energy efficiency, fuel switching, methane capture from coal plants and livestock, and even renewable energy. Renewable Energy Certificates (RECs) sold on the voluntary market are quite controversial due to additionality concerns.^[39] Industrial Gas projects receive criticism because such projects only apply to large industrial plants that already have high fixed costs. Siphoning off industrial gas for sequestration is considered picking the low hanging fruit; which is why credits generated from industrial gas projects are the cheapest in the voluntary market.

The size and activity of the voluntary carbon market is difficult to measure. The most comprehensive report on the voluntary carbon markets to date was released by Ecosystem Marketplace and New Carbon Finance in July 2007.^[38]

ÆON of Japan is firstly approved by Japanese authority to indicate carbon footprint on three private brand goods in October 2009.

Ways to reduce carbon footprint

The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. In manufacturing this can be done by recycling the packing materials, by selling the obsolete inventory of one industry to the industry who is looking to buy unused items at lesser price to become competitive. Nothing should be disposed off into the soil, all the ferrous materials which are prone to degrade or oxidize with time should be sold as early as possible at reduced price.

This can also be done by using reusable items such as thermoses for daily coffee or plastic containers for water and other cold beverages rather than disposable ones. If that option isn't available, it is best to properly recycle the disposable items after use. When one household recycles at least half of their household waste, they can save 1.2 tons of carbon dioxide annually^{[40][unreliable source?]}.

Another easy option is to drive less. By walking or biking to the destination rather than driving, not only is a person going to save money on gas, but they will be burning less fuel and releasing fewer emissions into the atmosphere. However, if walking is not an option, one can look into carpooling or mass transportation options in their area.

Yet another option for reducing the carbon footprint of humans is to use less air conditioning and heating in the home. By adding insulation to the walls and attic of one's home, and installing weather stripping or caulking around doors and windows one can lower their heating costs more than 25 percent. Similarly, one can very inexpensively upgrade the “insulation” (clothing) worn by residents of the home.^[41] For example, it's estimated that wearing a base layer of long underwear (top and bottom) made from a lightweight, super insulating fabric like microfleece (aka Polartec®, Capilene®) can conserve as much body heat as a full set of clothing, allowing a person to remain warm with the thermostat lowered by over 5 °C.^[41][42] These measures all help because they reduce the amount of energy needed to heat and cool the house. One can also turn down the heat while sleeping at night or away during the day, and keep temperatures moderate at all times. Setting the thermostat just 2 degrees lower in winter and higher in summer could save about 1 ton of carbon dioxide each year ^{[40][unreliable source?]}.

Choice of diet is a major influence on a person's carbon footprint. Animal sources of protein (especially red meat), rice (typically produced in high methane-emitting paddies), foods transported long distance and/or via fuel-inefficient transport (e.g., highly perishable produce flown long distance) and heavily processed and packaged foods are among the major contributors to a high carbon diet. Scientists at the University of Chicago have estimated^[43] "that the average American diet – which derives 28% of its calories from animal foods – is responsible for approximately one and a half more tonnes of greenhouse gasses – as CO2 equivalents – per person, per year than a fully plant-based, or vegan, diet."^[44] Their calculations suggest that even replacing one third of the animal protein in the average American's diet with plant protein (e.g., beans, grains) can reduce the diet's carbon footprint by half a tonne. Exchanging two thirds of the animal protein with plant protein is roughly equivalent to switching from a Toyota Camry to a Prius. Finally, throwing food out not only adds its associated carbon emissions to a person or household's footprint, it adds the emissions of transporting the wasted food to the garbage dump and the emissions of food decomposition, mostly in the form of the highly potent greenhouse gas, methane.

The carbon handprint movement emphasizes individual forms of carbon offsetting, like using more public transportation or planting trees in deforested regions, to reduce one's carbon footprint and increase their "handprint."^[45]

Furthermore, the carbon footprint in the food industry can be reduced by optimizing the supply chain. A life cycle or supply chain carbon footprint study can provide useful data which will help the business to identify critical areas for improvement and provides a focus. Such studies also demonstrate a company’s commitment to reducing carbon footprint now ahead of other competitors as well as preparing companies for potential regulation. In addition to increased market advantage and differentiation eco-efficiency can also help to reduce costs where alternative energy systems are implemented.

GHG footprint

The GHG footprint, or greenhouse gas footprint, refers to the amount of GHG that are emitted during the creation of products or services. It is more comprehensive than the commonly used carbon footprint, which measures only carbon dioxide, one of many greenhouse gases.