Climate change mitigation consists of actions to limit the magnitude or rate of long-term global warming and its related effects. Climate change mitigation generally involves reductions in human (anthropogenic) emissions of greenhouse gases (GHGs). Mitigation may also be achieved by increasing the capacity of carbon sinks, e.g., through reforestation. Mitigation policies can substantially reduce the risks associated with human-induced global warming.
According to the IPCC's 2014 assessment report, "Mitigation is a public good; climate change is a case of the 'tragedy of the commons'. Effective climate change mitigation will not be achieved if each agent (individual, institution or country) acts independently in its own selfish interest (see International cooperation and Emissions trading), suggesting the need for collective action. Some adaptation actions, on the other hand, have characteristics of a private good as benefits of actions may accrue more directly to the individuals, regions, or countries that undertake them, at least in the short term. Nevertheless, financing such adaptive activities remains an issue, particularly for poor individuals and countries."
Examples of mitigation include reducing energy demand by increasing energy efficiency, phasing out fossil fuels by switching to low-carbon energy sources, and removing carbon dioxide from Earth's atmosphere. Another approach to climate change mitigation is climate engineering. Climate change mitigation measures can be written down in national environmental policy documents of countries (for instance the nationally determined contributions (NDC) under the Paris agreement).
Almost all countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC). The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference with the climate system. Scientific analysis can provide information on the impacts of climate change, but deciding which impacts are dangerous requires value judgments.
In 2010, Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level. With the Paris Agreement of 2015 this was confirmed, but was revised with a new target laying down "parties will do the best" to achieve warming below 1.5 °C. The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 °C. Other mitigation policies have been proposed, some of which are more modest than the 2 °C limit. In 2019, after 2 years of research, scientists from Australia, and Germany presented the "One Earth Climate Model" showing how temperature increase can be limited to 1.5 °C for 1.7 trillion dollars a year.
One of the issues often discussed in relation to climate change mitigation is the stabilization of greenhouse gas concentrations in the atmosphere. The United Nations Framework Convention on Climate Change (UNFCCC) has the ultimate objective of preventing "dangerous" anthropogenic (i.e., human) interference with the climate system. As is stated in Article 2 of the Convention, this requires that greenhouse gas (GHG) concentrations are stabilized in the atmosphere at a level where ecosystems can adapt naturally to climate change, food production is not threatened, and economic development can proceed in a sustainable fashion.
There are a number of anthropogenic greenhouse gases. These include carbon dioxide (chemical formula: CO
2), methane (CH
4), nitrous oxide (N
2O), and a group of gases referred to as halocarbons. Another greenhouse gas, water vapor, has also risen as an indirect result of human activities. The emissions reductions necessary to stabilize the atmospheric concentrations of these gases varies. CO
2 is the most important of the anthropogenic greenhouse gases (see radiative forcing).
There is a difference between stabilizing CO
2 emissions and stabilizing atmospheric concentrations of CO
2. Stabilizing emissions of CO2 at current levels would not lead to a stabilization in the atmospheric concentration of CO2. In fact, stabilizing emissions at current levels would result in the atmospheric concentration of CO2 continuing to rise over the 21st century and beyond (see the graphs opposite).
The reason for this is that human activities are adding CO2 to the atmosphere faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a complete explanation). This is analogous to a flow of water into a bathtub. So long as the tap runs water (analogous to the emission of carbon dioxide) into the tub faster than water escapes through the plughole (analogous to the natural removal of carbon dioxide from the atmosphere) the level of water in the tub (analogous to the concentration of carbon dioxide in the atmosphere) will continue to rise.
According to some studies, stabilizing atmospheric CO2 concentrations would require anthropogenic CO2 emissions to be reduced by 80% relative to the peak emissions level. An 80% reduction in emissions would stabilize CO
2 concentrations for around a century, but even greater reductions would be required beyond this. Other research has found that, after leaving room for emissions for food production for 9 billion people and to keep the global temperature rise below 2 °C, emissions from energy production and transport will have to peak almost immediately in the developed world and decline at ca. 10% per annum until zero emissions are reached around 2030.
In 2018 an international team of scientist published research saying that the current mitigation policy in Paris Agreement is insufficient to limit the temperature rise to 2 degrees. They say that even if all the current pledges will be accomplished there is a chance for a 4.5 degree temperature rise in decades. To prevent that, restoration of natural Carbon sinks, Carbon dioxide removal, changes in society and values will be necessary.
Numerous assessments have considered how atmospheric GHG concentrations could be stabilized. The lower the desired stabilization level, the sooner global GHG emissions must peak and decline. GHG concentrations are unlikely to stabilize this century without major policy changes.
David Attenborough, in testimony to the UK House of Commons Business, Energy and Industrial Strategy Committee.
Assessments often suggest that GHG emissions can be reduced using a portfolio of low-carbon technologies. At the core of most proposals is the reduction of greenhouse gas (GHG) emissions through reducing energy waste and switching to low-carbon power sources of energy. As the cost of reducing GHG emissions in the electricity sector appears to be lower than in other sectors, such as in the transportation sector, the electricity sector may deliver the largest proportional carbon reductions under an economically efficient climate policy.
Other frequently discussed means include efficiency, public transport, increasing fuel economy in automobiles (which includes the use of electric hybrids), charging plug-in hybrids and electric cars by low-carbon electricity, making individual changes, and changing business practices. Replacing gasoline and diesel vehicles with electric means their emissions would be displaced away from street level, where they cause illness. Increased use of electricity could be met through low-carbon sources such as renewables and nuclear.
A range of energy technologies may contribute to climate change mitigation. These include nuclear power and renewable energy sources such as biomass, hydroelectricity, wind power, solar power, geothermal power, ocean energy, and; the use of carbon sinks, and carbon capture and storage.
Another consideration is how future socioeconomic development proceeds. Development choices (or "shared socioeconomic pathways") can lead to differences in GHG emissions. Political and social attitudes may affect how easy or difficult it is to implement effective policies to reduce emissions.
Natural gas emits far fewer greenhouse gases (i.e. CO
2 and methane—CH4) than coal when burned at power plants, but over the timescale available to prevent warming over 2 degrees this benefit may be completely negated by methane leakage at gas drilling fields and other points in the supply chain.
Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.
Climate change concerns and the need to reduce carbon emissions are driving increasing growth in the renewable energy industries. Low-carbon renewable energy replaces conventional fossil fuels in three main areas: power generation, hot water/ space heating, and transport fuels.
Renewable energy use has grown much faster than anyone anticipated. The Intergovernmental Panel on Climate Change (IPCC) has said that there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand. At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply.
Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. The incentive to use 100% renewable energy has been created by global warming and other ecological as well as economic concerns. Globally, there are an estimated 3 million direct jobs in renewable energy industries, with about half of them in the biofuels industry.
Some countries, with favorable geography, geology, and weather well suited to an economical exploitation of renewable energy sources, already get most of their electricity from renewables. Renewable power generators are spread across many countries, with wind power providing a significant share of electricity in some regional areas. Solar water heating makes an important and growing contribution in many countries, most notably in China, which now has 70 percent of the global total (180 GWth). Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households. The use of biomass for heating continues to grow as well. Direct geothermal heating is also growing rapidly.
Renewable biofuels are starting to be used in aviation.
As of 2019[update] the cost of extending nuclear power plant lifetimes is competitive with other electricity generation technologies, including new solar and wind projects. Many new plants are being built in China. Public opinion about nuclear power varies widely between countries. Nuclear fusion research, in the form of the International Thermonuclear Experimental Reactor is underway but fusion is not likely to be commercially widespread before 2050.
A heat pump is a device that provides heat energy from a source of heat to a destination called a "heat sink". Heat pumps are designed to move thermal energy opposite to the direction of spontaneous heat flow by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses some amount of external power to accomplish the work of transferring energy from the heat source to the heat sink.
While air conditioners and freezers are familiar examples of heat pumps, the term "heat pump" is more general and applies to many HVAC (heating, ventilating, and air conditioning) devices used for space heating or space cooling. When a heat pump is used for heating, it employs the same basic refrigeration-type cycle used by an air conditioner or a refrigerator, but in the opposite direction—releasing heat into the conditioned space rather than the surrounding environment. In this use, heat pumps generally draw heat from the cooler external air or from the ground. In heating mode, heat pumps are three to four times more efficient in their use of electric power than simple electrical resistance heaters.
It has been concluded that heat pumps are the single technology that could reduce the greenhouse gas emissions of households better than every other technology that is available on the market. With a market share of 30% and (potentially) clean electricity, heat pumps could reduce global CO
2 emissions by 8% annually. Using ground source heat pumps could reduce around 60% of the primary energy demand and 90% of CO
2 emissions in Europe in 2050 and make handling high shares of renewable energy easier. Using surplus renewable energy in heat pumps is regarded as the most effective household means to reduce global warming and fossil fuel depletion.
With significant amounts of fossil fuel used in electricity production, demands on the electrical grid also generate greenhouse gases. Without a high share[quantify] of low-carbon electricity, a domestic heat pump will produce more carbon emissions than using natural gas.
Fossil fuel may be phased-out with carbon-neutral and carbon-negative pipeline and transportation fuels created with power to gas and gas to liquids technologies. Carbon dioxide from fossil fuel flue gas can be used to produce plastic lumber allowing carbon negative reforestation.
The IPCC Fifth Assessment Report emphasises that behaviour, lifestyle, and cultural change have a high mitigation potential in some sectors, particularly when complementing technological and structural change.:20 In general, higher consumption lifestyles have a greater environmental impact. Several scientific studies have shown that when relatively rich people wish to reduce their carbon footprint, there are a few key actions they can take such as living car-free (2.4 tonnes CO2), avoiding one round-trip transatlantic flight (1.6 tonnes) and eating a plant-based diet (0.8 tonnes).
These appear to differ significantly from the popular advice for “greening” one's lifestyle, which seem to fall mostly into the “low-impact” category: Replacing a typical car with a hybrid (0.52 tonnes); Washing clothes in cold water (0.25 tonnes); Recycling (0.21 tonnes); Upgrading light bulbs (0.10 tonnes); etc. The researchers found that public discourse on reducing one's carbon footprint overwhelmingly focuses on low-impact behaviors, and that mention of the high-impact behaviors is almost non-existent in the mainstream media, government publications, K-12 school textbooks, etc.
The researchers added that “Our recommended high-impact actions are more effective than many more commonly discussed options (e.g. eating a plant-based diet saves eight times more emissions than upgrading light bulbs).”
Overall, food accounts for the largest share of consumption-based GHG emissions with nearly 20% of the global carbon footprint, followed by housing, mobility, services, manufactured products, and construction. Food and services are more significant in poor countries, while mobility and manufactured goods are more significant in rich countries.:327 The widespread adoption of a vegetarian diet could cut food-related greenhouse gas emissions by 63% by 2050. China introduced new dietary guidelines in 2016 which aim to cut meat consumption by 50% and thereby reduce greenhouse gas emissions by 1 billion tonnes by 2030. A 2016 study concluded that taxes on meat and milk could simultaneously result in reduced greenhouse gas emissions and healthier diets. The study analyzed surcharges of 40% on beef and 20% on milk and suggests that an optimum plan would reduce emissions by 1 billion tonnes per year.
Efficient energy use, sometimes simply called "energy efficiency", is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature. Installing LED lighting, or natural skylight windows reduces the amount of energy required to attain the same level of illumination compared to using traditional incandescent light bulbs. LED lamps use only about 10% of the energy an incandescent lamp requires.
Energy conservation is broader than energy efficiency in that it encompasses using less energy to achieve a lesser energy demanding service, for example through behavioral change, as well as encompassing energy efficiency. Examples of conservation without efficiency improvements would be heating a room less in winter or driving less. As with other definitions, the boundary between efficient energy use and energy conservation can be fuzzy, but both are important in environmental and economic terms. This is especially the case when actions are directed at the saving of fossil fuels.
Reducing energy use is seen as a key solution to the problem of reducing greenhouse gas emissions. According to the International Energy Agency, improved energy efficiency in buildings, industrial processes and transportation could reduce the world's energy needs in 2050 by one third, and help control global emissions of greenhouse gases.
Fuel switching on the demand side refers to changing the type of fuel used to satisfy a need for an energy service. To meet deep decarbonization goals, like the net zero goal being discussed in the European Union, many primary energy changes are needed. Energy efficiency alone may not be sufficient to meet these goals, switching fuels used on the demand side will help lower carbon emissions. Progressively coal, oil and eventually natural gas for space and water heating in buildings will need to be reduced. For an equivalent amount of heat, burning natural gas produces about 45 per cent less carbon dioxide than burning coal. There are various ways in which this could happen, and different strategies will likely make sense in different locations. While the system efficiency of a gas furnace may be higher than the combination of natural gas power plant and electric heat, the combination of the same natural gas power plant and an electric heat pump has lower emissions per unit of heat delivered in all but the coldest climates. This is possible because of the very efficient coefficient of performance of heat pumps.
At the beginning of this century 70% of all electricity was generated by fossil fuels, and as carbon free sources eventually make up half of the generation mix, replacing gas or oil furnaces and water heaters with electric ones will have a climate benefit. In areas like Norway, Brazil, and Quebec that have abundant hydroelectricity, electric heat and hot water are common.
The economics of switching the demand side from fossil fuels to electricity for heating, will depend on the price of fuels vs electricity and the relative prices of the equipment. Electrifying heating loads may also provide a flexible resource that can participate in demand response. Since thermostatically controlled loads have inherent energy storage, electrification of heating could provide a valuable resource to integrate variable renewable resources into the grid.
Expanding intermittent electrical sources such as wind power, creates a growing problem balancing grid fluctuations. Some of the plans include building pumped storage or continental super grids costing billions of dollars. However instead of building for more power, there are a variety of ways to affect the size and timing of electricity demand on the consumer side. Designing for reduced demands on a smaller power grid is more efficient and economic than having extra generation and transmission for intermittency, power failures and peak demands. Having these abilities is one of the chief aims of a smart grid.
Time of use metering is a common way to motivate electricity users to reduce their peak load consumption. For instance, running dishwashers and laundry at night after the peak has passed, reduces electricity costs.
Dynamic demand plans have devices passively shut off when stress is sensed on the electrical grid. This method may work very well with thermostats, when power on the grid sags a small amount, a low power temperature setting is automatically selected reducing the load on the grid. For instance millions of refrigerators reduce their consumption when clouds pass over solar installations. Consumers would need to have a smart meter in order for the utility to calculate credits.
Demand response devices could receive all sorts of messages from the grid. The message could be a request to use a low power mode similar to dynamic demand, to shut off entirely during a sudden failure on the grid, or notifications about the current and expected prices for power. This would allow electric cars to recharge at the least expensive rates independent of the time of day. Vehicle-to-grid uses a car's battery or fuel cell to supply the grid temporarily.
A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period, such as a growing forest. Carbon dioxide removal on the other hand is a permanent removal of carbon dioxide out of the atmosphere. Examples are direct air capture, enhanced weathering technologies such as storing it in geologic formations underground and biochar. These processes are sometimes considered as variations of sinks or mitigation, and sometimes as geoengineering. In combination with other mitigation measures, carbon sinks and removal are crucial for meeting the 2 degree target.
The Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) notes that one third of humankind's annual emissions of CO
2 are absorbed by the oceans. However, this also leads to ocean acidification, which may harm marine life. Acidification lowers the level of carbonate ions available for calcifying organisms to form their shells. These organisms include plankton species that contribute to the foundation of the Southern Ocean food web. However acidification may impact on a broad range of other physiological and ecological processes, such as fish respiration, larval development and changes in the solubility of both nutrients and toxins.
According to a research by Tom Crowther et al, there is still enough room to plant an additional 1.2 trillion trees. This amount of trees would cancel out the last 10 years of CO2 emissions and sequester 160 billion tons of carbon.This vision is being executed by the Trillion Tree Campaign. According to research conducted at ETH Zurich, restoring all degraded forests all over the world could capture about 205 billion tons of carbon in total (which is about 2/3rd of all carbon emissions, bringing global warming down to below 2 °C).
Almost 20 percent (8 GtCO2/year) of total greenhouse-gas emissions were from deforestation in 2007. It is estimated that avoided deforestation reduces CO2 emissions at a rate of 1 tonne of CO2 per $1–5 in opportunity costs from lost agriculture. Reforestation could save at least another 1 GtCO2/year, at an estimated cost of $5–15/tCO2. Afforestation is where there was previously no forest – such plantations are estimated to have to be prohibitively massive to reduce emissions by itself.
Transferring rights over land from public domain to its indigenous inhabitants, who have had a stake for millennia in preserving the forests that they depend on, is argued to be a cost effective strategy to conserve forests. This includes the protection of such rights entitled in existing laws, such as India's Forest Rights Act. The transferring of such rights in China, perhaps the largest land reform in modern times, has been argued to have increased forest cover. Granting title of the land has shown to have two or three times less clearing than even state run parks, notably in the Brazilian Amazon. Excluding humans and even evicting inhabitants from protected areas (called "fortress conservation") often lead to more exploitation of the land as the native inhabitants then turn to work for extractive companies to survive.
With increased intensive agriculture and urbanization, there is an increase in the amount of abandoned farmland. By some estimates, for every half a hectare of original old-growth forest cut down, more than 20 hectares of new secondary forests are growing, even though they do not have the same biodiversity as the original forests and original forests store 60% more carbon than these new secondary forests. According to a study in Science, promoting regrowth on abandoned farmland could offset years of carbon emissions. Research by the university ETH Zurich estimates that Russia, the United States and Canada have the most land suitable for reforestation.
Restoring grasslands store CO2 from the air into plant material. Grazing livestock, usually not left to wander, would eat the grass and would minimize any grass growth. However, grass left alone would eventually grow to cover its own growing buds, preventing them from photosynthesizing and the dying plant would stay in place. A method proposed to restore grasslands uses fences with many small paddocks and moving herds from one paddock to another after a day a two in order to mimick natural grazers and allowing the grass to grow optimally. Additionally, when part of leaf matter is consumed by a herding animal, a corresponding amount of root matter is sloughed off too as it would not be able to sustain the previous amount of root matter and while most of the lost root matter would rot and enter the atmosphere, part of the carbon is sequestered into the soil. It is estimated that increasing the carbon content of the soils in the world's 3.5 billion hectares of agricultural grassland by 1% would offset nearly 12 years of CO2 emissions. Allan Savory, as part of holistic management, claims that while large herds are often blamed for desertification, prehistoric lands supported large or larger herds and areas where herds were removed in the United States are still desertifying.
Additionally, the global warming induced thawing of the permafrost, which stores about two times the amount of the carbon currently released in the atmosphere, releases the potent greenhouse gas, methane, in a positive feedback cycle that is feared to lead to a tipping point called runaway climate change. A method proposed to prevent such a scenario is to bring back large herbivores such as seen in Pleistocene Park, where their trampling naturally keep the ground cooler by eliminating shrubs and keeping the ground exposed to the cold air.
Carbon capture and storage (CCS) is a method to mitigate climate change by capturing carbon dioxide (CO2) from large point sources such as power plants and subsequently storing it away safely instead of releasing it into the atmosphere. The IPCC estimates that the costs of halting global warming would double without CCS. The International Energy Agency says CCS is "the most important single new technology for CO2 savings" in power generation and industry. Norway's Sleipner gas field, beginning in 1996, stores almost a million tons of CO2 a year to avoid penalties in producing natural gas with unusually high levels of CO2. According to a Sierra Club analysis, the US Kemper Project, which was due to be online in 2017, is the most expensive power plant ever built for the watts of electricity it will generate.
Enhanced weathering is the removal of carbon from the air into the earth, enhancing the natural carbon cycle where carbon is mineralized into rock. The CarbFix project couples with carbon capture and storage in power plants to turn carbon dioxide into stone in a relatively short period of two years. While this project used basalt rocks, olivine has also shown promise.
IPCC (2007) concluded that geoengineering options, such as ocean fertilization to remove CO2 from the atmosphere, remained largely unproven. It was judged that reliable cost estimates for geoengineering had not yet been published.
Chapter 28 of the National Academy of Sciences report Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base (1992) defined geoengineering as "options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry." They evaluated a range of options to try to give preliminary answers to two questions: can these options work and could they be carried out with a reasonable cost. They also sought to encourage discussion of a third question — what adverse side effects might there be. The following types of option were examined: reforestation, increasing ocean absorption of carbon dioxide (carbon sequestration) and screening out some sunlight. NAS also argued "Engineered countermeasures need to be evaluated but should not be implemented without broad understanding of the direct effects and the potential side effects, the ethical issues, and the risks." In July 2011 a report by the United States Government Accountability Office on geoengineering found that "[c]limate engineering technologies do not now offer a viable response to global climate change."
Carbon dioxide removal has been proposed as a method of reducing the amount of radiative forcing. A variety of means of artificially capturing and storing carbon, as well as of enhancing natural sequestration processes, are being explored. The main natural process is photosynthesis by plants and single-celled organisms (see biosequestration). Artificial processes vary, and concerns have been expressed about the long-term effects of some of these processes.
It is notable that the availability of cheap energy and appropriate sites for geological storage of carbon may make carbon dioxide air capture viable commercially. It is, however, generally expected that carbon dioxide air capture may be uneconomic when compared to carbon capture and storage from major sources — in particular, fossil fuel powered power stations, refineries, etc. As in the case of the US Kemper Project with carbon capture, costs of energy produced will grow significantly. However, captured CO2 can be used to force more crude oil out of oil fields, as Statoil and Shell have made plans to do. CO2 can also be used in commercial greenhouses, giving an opportunity to kick-start the technology.
The main purpose of solar radiation management is to reflect sunlight and thus reduce global warming. The ability of stratospheric sulfate aerosols to create a global dimming effect has made them a possible candidate for use in climate engineering projects.
CO2 is not the only GHG relevant to mitigation, and governments have acted to regulate the emissions of other GHGs emitted by human activities (anthropogenic GHGs). The emissions caps agreed to by most developed countries under the Kyoto Protocol regulate the emissions of almost all the anthropogenic GHGs. These gases are CO2, methane (CH4), nitrous oxide (N2O), the hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF6).
Stabilizing the atmospheric concentrations of the different anthropogenic GHGs requires an understanding of their different physical properties. Stabilization depends both on how quickly GHGs are added to the atmosphere and how fast they are removed. The rate of removal is measured by the atmospheric lifetime of the GHG in question (see the main GHG article for a list). Here, the lifetime is defined as the time required for a given perturbation of the GHG in the atmosphere to be reduced to 37% of its initial amount. Methane has a relatively short atmospheric lifetime of about 12 years, while N2O's lifetime is about 110 years. For methane, a reduction of about 30% below current emission levels would lead to a stabilization in its atmospheric concentration, while for N2O, an emissions reduction of more than 50% would be required.
Methane is a significantly more potent greenhouse gas than carbon dioxide in the amount of heat it can trap, especially in the short term. Burning one molecule of methane generates one molecule of carbon dioxide, indicating there may be no net benefit[clarification needed] in using gas as a fuel source. Reducing the amount of waste methane produced in the first place and moving away from use of gas as a fuel source will have a greater beneficial impact, as might other approaches to productive use of otherwise-wasted methane. In terms of prevention, vaccines are being developed in Australia to reduce the significant global warming contributions from methane released by livestock via flatulence and eructation.
Another physical property of the anthropogenic GHGs relevant to mitigation is the different abilities of the gases to trap heat (in the form of infrared radiation). Some gases are more effective at trapping heat than others, e.g., SF6 is 22,200 times more effective a GHG than CO2 on a per-kilogram basis. A measure for this physical property is the global warming potential (GWP), and is used in the Kyoto Protocol.
Although not designed for this purpose, the Montreal Protocol has probably benefited climate change mitigation efforts. The Montreal Protocol is an international treaty that has successfully reduced emissions of ozone-depleting substances (for example, CFCs), which are also greenhouse gases.
Transportation emissions account for roughly 1/4 of emissions worldwide and are even more important in terms of impact in developed nations especially in North America and Australia. Many citizens of countries like the United States and Canada who drive personal cars often, see well over half of their climate change impact stemming from the emissions produced from their cars. Modes of mass transportation such as bus, light rail (metro, subway, etc.), and long-distance rail are far and away the most energy-efficient means of motorized transportation for passengers, able to use in many cases over twenty times less energy per person-distance than a personal automobile. Modern energy-efficient technologies, such as electric vehicles and carbon-neutral synthetic gasoline and jet fuel may also help to reduce the consumption of petroleum, land use changes and emissions of carbon dioxide. Utilizing rail transport, especially electric rail, over the far less efficient air transport and truck transport significantly reduces emissions. With the use of electric trains and cars in transportation there is the opportunity to run them with low-carbon power, producing far fewer emissions.
Effective urban planning to reduce sprawl aims to decrease Vehicle Miles Travelled (VMT), lowering emissions from transportation. Personal cars are extremely inefficient at moving passengers, while public transport and bicycles are many times more efficient (as is the simplest form of human transportation, walking). All of these are encouraged by urban/community planning and are an effective way to reduce greenhouse gas emissions. Inefficient land use development practices have increased infrastructure costs as well as the amount of energy needed for transportation, community services, and buildings.
At the same time, a growing number of citizens and government officials have begun advocating a smarter approach to land use planning. These smart growth practices include compact community development, multiple transportation choices, mixed land uses, and practices to conserve green space. These programs offer environmental, economic, and quality-of-life benefits; and they also serve to reduce energy usage and greenhouse gas emissions.
Approaches such as New Urbanism and transit-oriented development seek to reduce distances travelled, especially by private vehicles, encourage public transit and make walking and cycling more attractive options. This is achieved through "medium-density", mixed-use planning and the concentration of housing within walking distance of town centers and transport nodes.
Smarter growth land use policies have both a direct and indirect effect on energy consuming behavior. For example, transportation energy usage, the number one user of petroleum fuels, could be significantly reduced through more compact and mixed use land development patterns, which in turn could be served by a greater variety of non-automotive based transportation choices.
New buildings can be constructed using passive solar building design, low-energy building, or zero-energy building techniques, using renewable heat sources. Existing buildings can be made more efficient through the use of insulation, high-efficiency appliances (particularly hot water heaters and furnaces), double- or triple-glazed gas-filled windows, external window shades, and building orientation and siting. Renewable heat sources such as shallow geothermal and passive solar energy reduce the amount of greenhouse gasses emitted. In addition to designing buildings which are more energy-efficient to heat, it is possible to design buildings that are more energy-efficient to cool by using lighter-coloured, more reflective materials in the development of urban areas (e.g. by painting roofs white) and planting trees. This saves energy because it cools buildings and reduces the urban heat island effect thus reducing the use of air conditioning.
An agriculture that mitigates climate change is generally called Sustainable agriculture defined as an agriculture that "meet society’s food and textile needs in the present without compromising the ability of future generations to meet their own needs".
One mode of agriculture considered as relatively sustainable, is Regenerative agriculture It includes several methods, the main of which are: conservation tillage, diversity, rotation and cover crops, minimizing physical disturbance, minimizing the usage of chemicals. It has other benefits like improving the state of the soil and consequently yields. Some of the big agricultural companies like General Mills and a lot of farms support it.
In the United States, soils account for about half of agricultural greenhouse gas emissions while agriculture, forestry and other land use emits 24%. Globally, livestock is responsible for 18 percent of greenhouse gas emissions, according to FAO's report called "Livestock's Long Shadow: Environmental Issues and Options"
The US EPA says soil management practices that can reduce the emissions of nitrous oxide (N2O) from soils include fertilizer usage, irrigation, and tillage. Manure management and rice cultivation also produce gaseous emissions.
Important mitigation options for reducing the greenhouse gas emissions from livestock (especially ruminants) include genetic selection introduction of methanotrophic bacteria into the rumen, diet modification and grazing management. Other options include just using ruminant-free alternatives instead, such as milk substitutes and meat analogues. Non-ruminant livestock (e.g. poultry) generates far fewer emissions.
Methods that enhance carbon sequestration in soil include no-till farming, residue mulching, cover cropping, and crop rotation, all of which are more widely used in organic farming than in conventional farming. Because only 5% of US farmland currently uses no-till and residue mulching, there is a large potential for carbon sequestration.
A 2015 study found that farming can deplete soil carbon and render soil incapable of supporting life; however, the study also showed that conservation farming can protect carbon in soils, and repair damage over time. The farming practice of cover crops has been recognized as climate-smart agriculture. Best management practices for European soils were described to be increase soil organic carbon: conversion of arable land to grassland, straw incorporation, reduced tillage, straw incorporation combined with reduced tillage, ley cropping system and cover crops.
One of the most important projects to mitigate climate change with agriculture was launched in 2019 by the "Global EverGreening Alliance". The target is to sequester carbon from the atmosphere with Agroforestry. By 2050 the restored land should sequestrate 20 billion of carbon annually
Another method being examined is to make carbon a new currency by introducing tradeable "personal carbon credits". The idea being it will encourage and motivate individuals to reduce their 'carbon footprint' by the way they live. Each citizen will receive a free annual quota of carbon that they can use to travel, buy food, and go about their business. It has been suggested that by using this concept it could actually solve two problems; pollution and poverty, old age pensioners will actually be better off because they fly less often, so they can cash in their quota at the end of the year to pay heating bills and so forth.
Various organizations promote human population planning as a means for mitigating global warming. Proposed measures include improving access to family planning and reproductive health care and information, reducing natalistic politics, public education about the consequences of continued population growth, and improving access of women to education and economic opportunities.
According to a 2017 study published in Environmental Research Letters, having one less child would have a much more substantial effect on greenhouse gas emissions compared with for example living car free or eating a plant-based diet. However this has been criticised: both as a category mistake for assigning descendants emissions to their ancestors and for the very long timescale of reductions.
Population control efforts are impeded by there being somewhat of a taboo in some countries against considering any such efforts. Also, various religions discourage or prohibit some or all forms of birth control. Population size has a vastly different per capita effect on global warming in different countries, since the per capita production of anthropogenic greenhouse gases varies greatly by country.
One way of estimating the cost of reducing emissions is by considering the likely costs of potential technological and output changes. Policy makers can compare the marginal abatement costs of different methods to assess the cost and amount of possible abatement over time. The marginal abatement costs of the various measures will differ by country, by sector, and over time. Mitigation costs will vary according to how and when emissions are cut: early, well-planned action will minimise the costs.
Many economists estimate the cost of climate change mitigation at between 1% and 2% of GDP. According to the One Earth Climate Model, a global investment of approximately $1.7 trillion per year would be needed to keep global warming below 1.5°C. The method used by the One Earth Climate Model does not resort to dangerous geo-engineering methods. Whereas this is a large sum, it is still far less then the subsidies governments currently provided to the ailing fossil fuel industry, estimated at more than $5 trillion per year by the International Monetary Fund.
Yohe et al. (2007) assessed the literature on sustainability and climate change. With high confidence, they suggested that up to the year 2050, an effort to cap greenhouse gas (GHG) emissions at 550 ppm would benefit developing countries significantly. This was judged to be especially the case when combined with enhanced adaptation. By 2100, however, it was still judged likely that there would be significant effects of global warming. This was judged to be the case even with aggressive mitigation and significantly enhanced adaptive capacity.
One of the aspects of mitigation is how to share the costs and benefits of mitigation policies. In terms of the politics of mitigation, the UNFCCC's ultimate objective is to stabilize concentrations of GHG in the atmosphere at a level that would prevent "dangerous" climate change (Rogner et al., 2007).
Rich people tend to emit more GHG than poor people. Activities of the poor that involve emissions of GHGs are often associated with basic needs, such as cooking. For richer people, emissions tend to be associated with things such as eating beef, cars, frequent flying, and air conditioning. The impacts of cutting emissions could therefore have different impacts on human welfare according to wealth.
There have been different proposals on how to allocate responsibility for cutting emissions (Banuri et al., 1996, pp. 103–105):
|“||Bringing down emissions of greenhouse gases asks a good deal of people, not least that they accept the science of climate change. It requires them to make sacrifices today so that future generations will suffer less, and to weigh the needs of people who are living far away.||”|
|— The Economist, 28 November 2015|
Many countries, both developing and developed, are aiming to use cleaner technologies (World Bank, 2010, p. 192). Use of these technologies aids mitigation and could result in substantial reductions in CO2 emissions. Policies include targets for emissions reductions, increased use of renewable energy, and increased energy efficiency. It is often argued that the results of climate change are more damaging in poor nations, where infrastructures are weak and few social services exist. The Commitment to Development Index is one attempt to analyze rich country policies taken to reduce their disproportionate use of the global commons. Countries do well if their greenhouse gas emissions are falling, if their gas taxes are high, if they do not subsidize the fishing industry, if they have a low fossil fuel rate per capita, and if they control imports of illegally cut tropical timber.
The main current international agreement on combating climate change is the Paris agreement. The Paris Agreement's long-term temperature goal is to keep the increase in global average temperature to well below 2°C above pre-industrial levels; and to pursue efforts to limit the increase to 1.5°C. Each country must determine, plan, and regularly report on the contribution that it undertakes to mitigate global warming.
It succeeds the Kyoto Protocol which expires in 2020, and is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC). Countries that ratified the Kyoto protocol committed to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases.
Actions to mitigate climate change are sometimes based on the goal of achieving a particular temperature target. One of the targets that has been suggested is to limit the future increase in global mean temperature (global warming) to below 2 °C, relative to the pre-industrial level. The 2 °C target was adopted in 2010 by Parties to the United Nations Framework Convention on Climate Change. Most countries of the world are Parties to the UNFCCC. The target had been adopted in 1996 by the European Union Council.
Temperatures have increased by 0.8 °C compared to the pre-industrial level, and another 0.5–0.7 °C is already committed. The 2 °C rise is typically associated in climate models with a carbon dioxide equivalent concentration of 400–500 ppm by volume; the current (January 2015) level of carbon dioxide alone is 400 ppm by volume, and rising at 1–3 ppm annually. Hence, to avoid a very likely breach of the 2 °C target, CO2 levels would have to be stabilised very soon; this is generally regarded as unlikely, based on current programs in place to date. The importance of change is illustrated by the fact that world economic energy efficiency is improving at only half the rate of world economic growth.
There is disagreement among experts over whether or not the 2 °C target can be met. For example, according to Anderson and Bows (2011), "there is little to no chance" of meeting the target. On the other hand, according to Alcamo et al. (2013):
Scientific analysis can provide information on the impacts of climate change and associated policies, such as reducing GHG emissions. However, deciding what policies are best requires value judgements. For example, limiting global warming to 1.5 °C relative to pre-industrial levels reduces climate change damages more than a 2 °C limit. However, a 1.5 °C limit may be more costly to achieve than a 2 °C limit.
According to some analysts, the 2 °C "guardrail" is inadequate for the needed degree and timeliness of mitigation.[clarification needed] On the other hand, some economic studies suggest more modest mitigation policies. For example, the emissions reductions proposed by Nordhaus (2010) might lead to global warming (in the year 2100) of around 3 °C, relative to pre-industrial levels.
In 2015, two official UNFCCC scientific expert bodies came to the conclusion that, "in some regions and vulnerable ecosystems, high risks are projected even for warming above 1.5 °C". This expert position was, together with the strong diplomatic voice of the poorest countries and the island nations in the Pacific, the driving force leading to the decision of the Paris Conference 2015, to lay down this 1.5 °C long-term target on top of the existing 2 °C goal.
An emissions tax on greenhouse gas emissions requires individual[clarification needed] emitters to pay a fee, charge or tax for every tonne of greenhouse gas released into the atmosphere. Most environmentally related taxes with implications for greenhouse gas emissions in OECD countries are levied on energy products and motor vehicles, rather than on CO2 emissions directly. As such, non-transport sectors as the agricultural sector (which too produces potent greenhouse gases, i.e. methane) are typically left untaxed[clarification needed]. Also, revenue of the emissions taxes are not always used to offset the emissions directly.
Emission taxes can be both cost-effective and environmentally effective. Difficulties with emission taxes include their potential unpopularity, and the fact that they cannot guarantee a particular level of emissions reduction. Emissions or energy taxes also often fall disproportionately on lower income classes. In developing countries, institutions may be insufficiently developed for the collection of emissions fees from a wide variety of sources.
Another indirect method of encouraging uses of renewable energy, and pursue sustainability and environmental protection, is that of prompting investment in this area through legal means, something that is already being done at national level as well as in the field of international investment.
With the creation of a market for trading carbon dioxide emissions within the Kyoto Protocol, it is likely that London financial markets will be the centre for this potentially highly lucrative business; the New York and Chicago stock markets may have a lower trade volume than expected as long as the US maintains its rejection of the Kyoto.
However, emissions trading may delay the phase-out of fossil fuels.
In the north-east United States, a successful cap and trade program has shown potential for this solution.
The European Union Emission Trading Scheme (EU ETS) is the largest multi-national, greenhouse gas emissions trading scheme in the world. It commenced operation on 1 January 2005, and all 28 member states of the European Union participate in the scheme which has created a new market in carbon dioxide allowances estimated at 35 billion Euros (US$43 billion) per year. The Chicago Climate Exchange was the first (voluntary) emissions market, and is soon to be followed by Asia's first market (Asia Carbon Exchange). A total of 107 million metric tonnes of carbon dioxide equivalent have been exchanged through projects in 2004, a 38% increase relative to 2003 (78 Mt CO2e).
Twenty three multinational corporations have come together in the G8 Climate Change Roundtable, a business group formed at the January 2005 World Economic Forum. The group includes Ford, Toyota, British Airways, and BP. On 9 June 2005 the Group published a statement stating that there was a need to act on climate change and claiming that market-based solutions can help. It called on governments to establish "clear, transparent, and consistent price signals" through "creation of a long-term policy framework" that would include all major producers of greenhouse gases.
The Regional Greenhouse Gas Initiative is a proposed carbon trading scheme being created by nine North-eastern and Mid-Atlantic American states; Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont. The scheme was due to be developed by April 2005 but has not yet been completed.
Implementation puts into effect climate change mitigation strategies and targets. These can be targets set by international bodies or voluntary action by individuals or institutions. This is the most important, expensive and least appealing aspect of environmental governance.
Funding, such as the Green Climate Fund, is often provided by nations, groups of nations and increasingly NGO and private sources. These funds are often channelled through the Global Environmental Facility (GEF). This is an environmental funding mechanism in the World Bank which is designed to deal with global environmental issues. The GEF was originally designed to tackle four main areas: biological diversity, climate change, international waters and ozone layer depletion, to which land degradation and persistent organic pollutant were added. The GEF funds projects that are agreed to achieve global environmental benefits that are endorsed by governments and screened by one of the GEF's implementing agencies.
There are numerous issues which result in a current perceived lack of implementation. It has been suggested that the main barriers to implementation are Uncertainty, Fragmentation, Institutional void, Short time horizon of policies and politicians and Missing motives and willingness to start adapting. The relationships between many climatic processes can cause large levels of uncertainty as they are not fully understood and can be a barrier to implementation. When information on climate change is held between the large numbers of actors involved it can be highly dispersed, context specific or difficult to access causing fragmentation to be a barrier. Institutional void is the lack of commonly accepted rules and norms for policy processes to take place, calling into question the legitimacy and efficacy of policy processes. The Short time horizon of policies and politicians often means that climate change policies are not implemented in favour of socially favoured societal issues. Statements are often posed to keep the illusion of political action to prevent or postpone decisions being made. Missing motives and willingness to start adapting is a large barrier as it prevents any implementation. The issues that arise with a system which involves international government cooperation, such as cap and trade, could potentially be improved with a polycentric approach where the rules are enforced by many small sections of authority as opposed to one overall enforcement agency. Concerns about metal requirement and/or availability for essential decarbonization technoloqies such as photovoltaics, nuclear power, and (plug-in hybrid) electric vehicles have also been expressed as obstacles.
Despite a perceived lack of occurrence,[clarification needed] evidence of implementation is emerging internationally. Some examples of this are the initiation of NAPA's and of joint implementation. Many developing nations have made National Adaptation Programs of Action (NAPAs) which are frameworks to prioritize adaption needs. The implementation of many of these is supported by GEF agencies. Many developed countries are implementing 'first generation'[clarification needed] institutional adaption plans particularly at the state and local government scale. There has also been a push towards joint implementation between countries by the UNFCCC as this has been suggested as a cost-effective way for objectives to be achieved.
Efforts to reduce greenhouse gas emissions by the United States include energy policies which encourage efficiency through programs like Energy Star, Commercial Building Integration, and the Industrial Technologies Program.
In the absence of substantial federal action, state governments have adopted emissions-control laws such as the Regional Greenhouse Gas Initiative in the Northeast and the Global Warming Solutions Act of 2006 in California. In 2019 a new climate change bill was introduced in Minnesota. One of the targets, is making all the energy of the state carbon free, by 2030.
As to 2019, China implements more than 100 policies to fight climate change. China said in the Paris Agreement that its emission will begin to fall by 2030, but it will possibly occur by 2026. This can position China as a leader on the issue because it is the biggest emitter of GHG emissions, so if it really reduces them, the significance will be large.
In April 2019 the Spanish Socialist Party takes the biggest number of seats in the elections in Spain. The party declares itself as part of the Green New Deal and propose: "reducing emissions by 90 percent below 1990 levels by mid-century and generating all of the country’s power from renewables along the same timeline; 74 percent of power would come from renewables by 2030. The bill would ban fracking nationwide, eliminate fossil fuel subsidies and government investments in fossil fuels, and phase out fossil-fueled vehicles, with the aim of banning the registration and sale of carbon-emitting vehicles by 2040"
Proposals to reach zero carbon economy in the European Union by 2050, were suggested in 2018 – 2019. The countries who support it: Belgium, France, Spain, Netherlands, Denmark, Luxembourg, Portugal, Latvia, Slovenia, Finland, Great Britain, Italy. The main obstacle is Germany, that is not decided yet about its position, and a number of others east – European countries are sceptical also: Bulgaria, Croatia, the Czech Republic and Poland, despite they are the most vulnerable to climate change.
In 2018 was published the Sustainable Action Plan to reorient capital flows toward sustainable investment and manage financial risks from environmental and social problems. In 2019 the European Commission adopted guidelines that help define an environmentally friendly investment. The European Commission is seeking to reduce emissions to zero by 2050. The guidelines set parameters on how businesses can qualify as "green" based on their contributions to the EU's 6 environmental objectives. The guidelines do not include coal and nuclear power and support 2030 goals: at least one-third share of renewable energy in final energy consumption, a one-third energy savings when compared to business-as-usual scenarios, a cut of minimum 40% in greenhouse gas emissions when compared to 1990 levels.
In order to reconcile economic development with mitigating carbon emissions, developing countries need particular support, both financial and technical. One of the means of achieving this is the Kyoto Protocol's Clean Development Mechanism (CDM). The World Bank's Prototype Carbon Fund is a public private partnership that operates within the CDM.
An important point of contention, however, is how overseas development assistance not directly related to climate change mitigation is affected by funds provided to climate change mitigation. One of the outcomes of the UNFCC Copenhagen Climate Conference was the Copenhagen Accord, in which developed countries promised to provide US$30 million between 2010 and 2012 of new and additional resources. Yet it remains unclear what exactly the definition of additional is and the European Commission has requested its member states to define what they understand to be additional, and researchers at the Overseas Development Institute have found four main understandings:
The main point being that there is a conflict between the OECD states budget deficit cuts, the need to help developing countries adapt to develop sustainably and the need to ensure that funding does not come from cutting aid to other important Millennium Development Goals.
However, none of these initiatives suggest a quantitative cap on the emissions from developing countries. This is considered as a particularly difficult policy proposal as the economic growth of developing countries are proportionally reflected in the growth of greenhouse emissions. Critics[who?] of mitigation often argue that, the developing countries' drive to attain a comparable living standard to the developed countries would doom the attempt at mitigation of global warming. Critics[who?] also argue that holding down emissions would shift the human cost of global warming from a general one to one that was borne most heavily by the poorest populations on the planet.
In an attempt to provide more opportunities for developing countries to adapt clean technologies, UNEP and WTO urged the international community to reduce trade barriers and to conclude the Doha trade round "which includes opening trade in environmental goods and services".
In 2019 week of climate action in Latin America and the Caribbean result in a declaration in which leaders says that they will act to reduce emissions in the sectors of transportation, energy, urbanism, industry, forest conservation and land use and "sent a message of solidarity with all the people of Brazil suffering the consequences of the rainforest fires in the Amazon region, underscoring that protecting the world’s forests is a collective responsibility, that forests are vital for life and that they are a critical part of the solution to climate change".
While many of the proposed methods of mitigating global warming require governmental funding, legislation and regulatory action, individuals and businesses can also play a part in the mitigation effort.
Environmental groups encourage individual action against global warming, often aimed at the consumer. Common recommendations include lowering home heating and cooling usage, burning less gasoline, supporting renewable energy sources, buying local products to reduce transportation, turning off unused devices, and various others.
A geophysicist at Utrecht University has urged similar institutions to hold the vanguard in voluntary mitigation, suggesting the use of communications technologies such as videoconferencing to reduce their dependence on long-haul flights.
In 2008, climate scientist Kevin Anderson raised concern about the growing effect of rapidly increasing global air transport on the climate in a paper, and a presentation, suggesting that reversing this trend is necessary to reduce emissions.
Part of the difficulty is that when aviation emissions are made at high altitude, the climate impacts are much greater than otherwise. Others have been raising the related concerns of the increasing hypermobility of individuals, whether traveling for business or pleasure, involving frequent and often long distance air travel, as well as air shipment of goods.
Climate change is also a concern for large institutional investors who have a long term time horizon and potentially large exposure to the negative impacts of global warming because of the large geographic footprint of their multi-national holdings. Socially responsible investing funds allow investors to invest in funds that meet high ESG (environmental, social, governance) standards as such funds invest in companies that are aligned with these goals. Proxy firms can be used to draft guidelines for investment managers that take these concerns into account.
In some countries, those affected by climate change may be able to sue major producers. Attempts at litigation have been initiated by entire peoples such as Palau and the Inuit, as well as non-governmental organizations such as the Sierra Club. Although proving that particular weather events are due specifically to global warming may never be possible, methodologies have been developed to show the increased risk of such events caused by global warming.
For a legal action for negligence (or similar) to succeed, "Plaintiffs ... must show that, more probably than not, their individual injuries were caused by the risk factor in question, as opposed to any other cause. This has sometimes been translated to a requirement of a relative risk of at least two." Another route (though with little legal bite) is the World Heritage Convention, if it can be shown that climate change is affecting World Heritage Sites like Mount Everest.
Besides countries suing one another, there are also cases where people in a country have taken legal steps against their own government. Legal action for instance has been taken to try to force the US Environmental Protection Agency to regulate greenhouse gas emissions under the Clean Air Act, and against the Export-Import Bank and OPIC for failing to assess environmental impacts (including global warming impacts) under NEPA.
In the Netherlands and Belgium, organisations such as Urgenda and the vzw Klimaatzaak in Belgium have also sued their governments as they believe their governments aren't meeting the emission reductions they agreed to. Urgenda have already won their case against the Dutch government.
According to a 2004 study commissioned by Friends of the Earth, ExxonMobil, and its predecessors caused 4.7 to 5.3 percent of the world's man-made carbon dioxide emissions between 1882 and 2002. The group suggested that such studies could form the basis for eventual legal action.
In 2015, Exxon received a subpoena. According to the Washington Post and confirmed by the company, the attorney general of New York, Eric Schneiderman, opened an investigation into the possibility that the company had misled the public and investors about the risks of climate change. In October 2019 begun the trial. Massachusetts sued Exxon also, for hiding the impact of climate change.
Environmental organizations organize different actions such as Peoples Climate Marches and Divestment from fossil fuels. 1,000 organizations with a worth of 8 trillion dollars, made commitments to divest from fossil fuel to 2018. Another form of action is climate strike. In January 2019 12,500 students marched in Brussels demanding Climate action. In 2019 The organization Extinction Rebellion organized massive protests demanding "tell the truth about climate change, reduce carbon emissions to zero by 2025, and create a citizens' assembly to oversee progress", including blocking roads. Many were arrested. In many cases, activism brings positive results.
In 20 – 27 September 2019, a global climate strike is planned. The main organizers are Fridays For Future and Earth Strike. Trade unions will support the strike. The Universities and College Union (UCU) will propose in the next Trades Union Congress (TUC) of England in September to make a workday solidarity stoppage on September 20 in support of the strike. Any walkout would cooperate with the student protest. The target is to influence the climate action summit organized by the UN on September 23. According to the organizers four million people participated in the strike on September 20.
Much less frequently mentioned are, however, the ultimate drivers of those immediate causes of biotic destruction, namely, human overpopulation and continued population growth, and overconsumption, especially by the rich. These drivers, all of which trace to the fiction that perpetual growth can occur on a finite planet, are themselves increasing rapidly.
The overarching driver of species extinction is human population growth and increasing per capita consumption.
(esp. slide 24 onward)
Palau suing the industrialized countries over global warming
AR5 Working Group III Report