Mitigation options of greenhouse gases, Physiological and biochemical effects on biota avoidance and adaptation mechanisms in plants and animals

Mitigation refers to the policies and measures designed to reduce green house gas emissions. Measures can include reducing demand for emission-intensive goods and services, boosting efficiency gains, and increasing the use of low-carbon technologies. Another way to mitigate the impacts of climate change is by enhancing sinks/reservoirs that absorb CO₂, such as forests or peat bogs (a type of wetland where decomposition is slowed down and dead plant matter accumulates as peat).

According to IPCC mitigation is defined as “technological change and substitution that reduce resource inputs and emissions per unit of output with respect to climate change, mitigation means implementing policies to reduce GHG emissions and enhance sinks”.

To design an effective mitigation strategy, we need to know the GHG emission pattern, available mitigation options, role of technology and market-based mechanisms. We also need to design the mitigation strategy in such a way that it helps ensure sustainable development.

Mitigation Options

Options and strategies to mitigate climate change are crucial for stabilization of GHGs (to stop the increase of GHG concentrations in the atmosphere). Thus, it is vital to make necessary efforts and investments to reduce emissions.

Economic activities have a substantial potential for mitigation of GHG emissions over the coming decades. In other words, mitigation can create a positive financial result for the economy, for example, through the development of new technologies or through a reduction in energy costs.

Reducing GHG emissions by mitigation can have several co-benefits. It can result in large and rapid health benefits from reduced air pollution, which may also offset a substantial part of the mitigation costs.

Energy-efficiency and the use of renewable energy offer synergies with sustainable development. In the least-developed countries, for example, changing the source of energy from fuel wood to the solar energy has many benefits. It can lower disease and death rates by - cutting down on indoor air pollution, reducing the workload for women and children who have to go out and collect the fuel wood, and decreasing the unsustainable use of fuel wood and, thereby, deforestation.

Categorization of Mitigation Options

Market-oriented Policies: Collection of Taxes and giving subsidies, Emission charges, Fixing Tradable emission permits, disbursing soft loans, Market development and/or efforts to reduce transaction costs etc.,

Technology-oriented Policies: Fixing Norms and standards, Effluent or user charges, Institutional capacity building, Market development efforts (information, transaction cost coverage)

Voluntary Policies:  Eco-labelling and Voluntary agreements

Accompanying Measures: Public awareness, Information distribution and Education

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. for example, through improved building insulation. Another approach to climate change mitigation is climate engineering.

Most 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 of 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 stringent or modest than the 2 °C limit. In 2019, after 2 years of research, scientists from Australia, and Germany presented the "One Earth Climate Model" that shows how exactly we can stay below 1.5 degrees in price of 1.7 trillion dollars per year

Energy consumption by power source

To create lasting climate change mitigation, the replacement of high carbon emission intensity power sources, such as conventional fossil fuels—oil, coal, and natural gas—with low-carbon power sources is required. Fossil fuels supply humanity with the vast majority of our energy demands, and at a growing rate. In 2012 the IEA noted that coal accounted for half the increased energy use of the prior decade, growing faster than all renewable energy sources. Both hydroelectricity and nuclear power together provide the majority of the generated low-carbon power fraction of global total power consumption.

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. Many fossil fuel driven vehicles can be converted to use electricity, the US has the potential to supply electricity for 73% of light duty vehicles (LDV), using overnight charging. The US average CO₂emissions for a battery-electric car is 180 grams per mile vs 430 grams per mile for a gasoline car. The emissions would be displaced away from street level, where they have "high human-health implications. Increased use of electricity "generation for meeting the future transportation load is primarily fossil-fuel based", mostly natural gas, followed by coal, but could also be met through nuclear, tidal, hydroelectric and other sources.

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.

Demand side management

Lifestyle and behavior

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. In general, higher consumption lifestyles have a greater environmental impact. Several scientific studies have shown that when people, especially those living in developed countries but more generally including all countries, wish to reduce their carbon footprint, there are four key "high-impact" actions they can take:

1.   Not having an additional child (58.6 tonnes CO₂-equivalent emission reductions per year)

2.   Living car-free (2.4 tonnes CO₂)

3.   Avoiding one round-trip transatlantic flight (1.6 tonnes)

4.   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. It was 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 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). More significantly, a US family who chooses to have one fewer child would provide the same level of emissions reductions as 684 teenagers who choose to adopt comprehensive recycling for the rest of their lives.

Dietary change

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. The real-life diets of British people estimates their greenhouse gas contributions (CO₂eq) to be: 7.19 kg/day for high meat-eaters through to 3.81 kg/day for vegetarians and 2.89 kg/day for vegans. 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. Taxes on meat and milk could simultaneously result in reduced greenhouse gas emissions and healthier diets. Surcharges of 40% on beef and 20% on milk would reduce emissions by 1 billion tonnes per year.

Energy efficiency and conservation

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, fluorescent 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. Compact fluorescent lamps use only 33% of the energy and may last 6 to 10 times longer than incandescent lights. LED lamps use only about 10% of the energy an incandescent lamp requires.

Energy efficiency has proved to be a cost-effective strategy for building economies without necessarily growing energy consumption. For example, the state of California began implementing energy-efficiency measures in the mid-1970s, including building code and appliance standards with strict efficiency requirements. During the following years, California's energy consumption has remained approximately flat on a per capita basis while national US consumption doubled. As part of its strategy, California implemented a "loading order" for new energy resources that puts energy efficiency first, renewable electricity supplies second, and new fossil-fired power plants last.

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, driving less, or working in a less brightly lit room. 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.

Demand-side switching sources

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 80% reduction by 2050 goal being discussed in California and 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. The EIA Annual Energy Outlook 2014 suggests that domestic gas prices will rise faster than electricity prices which will encourage electrification in the coming decades. 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.

Alternatives to electrification, include decarbonizing pipeline gas through power to gas, biogas, or other carbon-neutral fuels. A hybrid approach of decarbonizing pipeline gas, electrification, and energy efficiency can meet carbon reduction goals at a similar cost as only electrification and energy efficiency in Southern California

Demand side grid management

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 intermittentcy, 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. The vehicle-to-grid suggestion would use a car's battery or fuel cell to supply the grid temporarily.

Alternative energy sources

Renewable energy

According to International Energy Agency Renewable energy flows involve natural phenomena such as sunlight, wind, rain, tides, plant growth, and geothermal heat.

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. 

In 2011, the share of renewables in electricity generation worldwide grew for the fourth year in a row to 20.2%. Based on REN21's 2014 report, renewables contributed 19% to supply global energy consumption. This energy consumption is divided as 9% coming from burning biomass, 4.2% as heat energy (non-biomass), 3.8% hydro electricity and 2% as electricity from wind, solar, geothermal, and biomass thermal power plants.

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.

As of 2012, renewable energy accounts for almost half of new electricity capacity installed and costs are continuing to fall. Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. As of 2011, 118 countries have targets for their own renewable energy futures, and have enacted wide-ranging public policies to promote renewable. 

The incentive to use 100% renewable energy has been created by global warming and other ecological as well as economic concerns. producing all new energy with wind power, solar power, and hydropower by 2030 is feasible and existing energy supply arrangements could be replaced by 2050.

Barriers to implementing the renewable energy plan are seen to be primarily social and political, not technological or economic. The energy costs with a wind, solar, water system should be similar to today's energy costs. 

According to International Energy Agency (IEA), solar power generators may produce most of the world's electricity within 50 years, dramatically reducing harmful greenhouse gas emissions.

100% renewable energy approach are concerned about the variable output of solar and wind power and a lack of infrastructure.

Economic analysts expect market gains for renewable energy (and efficient energy use) following the 2011 Japanese nuclear accidents. In his 2012 State of the Union address, President Barack Obama restated his commitment to renewable energy and mentioned the long-standing Interior Department commitment to permit 10,000 MW of renewable energy projects on public land in 2012. 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, including from geothermal energy in Iceland (100 percent), and hydroelectric power in Brazil (85 percent), Austria (62 percent), New Zealand (65 percent), and Sweden (54 percent). Renewable power generators are spread across many countries, with wind power providing a significant share of electricity in some regional areas: for example, 14 percent in the US state of Iowa, 40 percent in the northern German state of Schleswig-Holstein, and 20 percent in Denmark. Solar water heating makes an important and growing contribution in many countries, most notably in China, which now has 70 per cent 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. In Sweden, national use of biomass energy has surpassed that of oil.

Direct geothermal heating is also growing rapidly. Renewable biofuels for transportation, such as ethanol fuel and biodiesel, have contributed to a significant decline in oil consumption in the United States since 2006. The 93 billion liters of biofuels produced worldwide in 2009 displaced the equivalent of an estimated 68 billion liters of gasoline, equal to about 5 percent of world gasoline production.

Nuclear power

Since about 2001 the term "nuclear renaissance" has been used to refer to a possible nuclear power industry revival, driven by rising fossil fuel prices and new concerns about meeting greenhouse gas emission limits. However, in March 2011 the Fukushima nuclear disaster in Japan and associated shutdowns at other nuclear facilities raised questions among some commentators over the future of nuclear power. The crisis at Japan's Fukushima nuclear plants has prompted leading energy-consuming countries to review the safety of their existing reactors and cast doubt on the speed and scale of planned expansions around the world.

According to World Nuclear Association, nuclear electricity generation in 2012 was at its lowest level since 1999. As part of the portfolio of other low-carbon energy technologies, nuclear power will continue to play a role in reducing greenhouse gas emissions. Historically, nuclear power usage is estimated to have prevented the atmospheric emission of 64 giga tonnes of CO₂-equivalent as of 2013. 

Public concerns about nuclear power include the fate of spent nuclear fuel, nuclear accidents, security risks, nuclear proliferation, and a concern that nuclear power plants are very expensive. Of these concerns, nuclear accidents and disposal of long-lived radioactive fuel/"waste" have probably had the greatest public impact worldwide. Although generally unaware of it, both of these glaring public concerns are greatly diminished by present passive safety designs, the experimentally proven, "melt-down proof" EBR-II, future molten salt reactors, and the use of conventional and more advanced fuel/"waste" pyroprocessing, with the latter recycling or reprocessing not presently being commonplace as it is often considered to be cheaper to use a once-through nuclear fuel cycle in many countries, depending on the varying levels of intrinsic value given by a society in reducing the long-lived waste in their country, with France doing a considerable amount of reprocessing when compared to the US.

Nuclear power, with a 10.6% share of world electricity production as of 2013, is second only to hydroelectricity as the largest source of low-carbon power. Over 400 reactors generate electricity in 31 countries.

With the most cost effective low carbon power technology being determined to be nuclear power.

The principal limitations on nuclear fission are not technical, economic or fuel-related, but are instead linked to complex issues of societal acceptance, fiscal and political inertia, and inadequate critical evaluation of the real-world constraints facing [the other] low-carbon alternatives.

Nuclear power may be uncompetitive compared with fossil fuel energy sources in countries without a carbon tax program, and in comparison to a fossil fuel plant of the same power output, nuclear power plants take a longer amount of time to construct.

Coal to gas fuel switching

Most mitigation proposals imply—rather than directly state—an eventual reduction in global fossil fuel production. Also proposed are direct quotas on global fossil fuel production.

Natural gas emits far fewer greenhouse gases (i.e. CO₂ and methane—CH₄) than coal when burned at power plants, but evidence has been emerging that this benefit could be completely negated by methane leakage at gas drilling fields and other points in the supply chain.

Heat pump

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 CO₂ emissions by 8% annually. Using ground source heat pumps could reduce around 60% of the primary energy demand and 90% of CO₂ 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 of low-carbon electricity, a domestic heat pump will produce more carbon emissions than using natural gas

Sinks and negative emissions

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. A negative carbon dioxide emission 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, sinks in combination with negative carbon emissions are considered crucial for meeting the 350 ppm target.

The Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) notes that one third of humankind's annual emissions of CO₂ are absorbed by the oceans. However, this also leads to ocean acidification, with potentially significant impacts on 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

Reforestation and afforestation

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 be 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"), sometimes as a result of lobbying by environmental groups, 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. Promoting regrowth on abandoned farmland could offset years of carbon emissions.

Avoided desertification

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 under the process of desertification.

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

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 CO₂savings" in power generation and industry. Though it requires up to 40% more energy to run a CCS coal power plant than a regular coal plant, CCS could potentially capture about 90% of all the carbon emitted by the plant. 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. As of late 2011, the total planned CO₂ storage capacity of all 14 projects in operation or under construction is over 33 million tonnes a year. This is broadly equivalent to preventing the emissions from more than six million cars from entering the atmosphere each year. According to a Sierra Club analysis, the US coal fired Kemper Project due to be online in 2017, is the most expensive power plant ever built for the watts of electricity it will generate.

Enhanced weathering

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, addressing the common concern of leakage in CCS projects. While this project used basaltrocks, olivine has also shown promise.

Non-CO₂ greenhouse gases

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 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.

By sector

Transport

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 plug-in hybrid electric vehicles and carbon-neutral synthetic gasoline & 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.

Urban planning

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. Between 1982 and 1997, the amount of land consumed for urban development in the United States increased by 47 percent while the nation's population grew by only 17 percent. 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.

Building design

Emissions from housing are substantial, and government-supported energy efficiency programmes can make a difference.

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.

Agriculture

According to the EPA, agricultural soil management practices can lead to production and emission of nitrous oxide (N₂O), a major greenhouse gas and air pollutant. Activities that can contribute to N₂O emissions include fertilizer usage, irrigation, and tillage. The management of soils accounts for over half of the emissions from the Agriculture sector. Cattle live stocks account for one third of emissions, through methane emissions. Manure management and rice cultivation also produce gaseous emissions.

Methods that significantly 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.

Intensive farming can deplete soil carbon and render soil incapable of supporting life; however, the conservation farming can protect carbon in soils, and repair damage over time. The farming practise of cover crops has been recognized as climate-smart agriculture by the White House.

In Europe the estimation of the current 0–30 cm SOC stock of agricultural soils was 17.63 Gt. The best management practices to mitigate soil organic carbon include conversion of arable land to grassland (and vice versa), straw incorporation, reduced tillage, straw incorporation combined with reduced tillage, alley cropping system and cover crops.

Societal controls

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.

Population

Various organizations promote population control 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.

Having one less child would have a much more substantial effect on greenhouse gas emissions compared with living car free or eating a plant-based diet.

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 different per capita effect on global warming in different countries, since the per capita production of anthropogenic greenhouse gases varies greatly by country.

Sharing

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.

GHG emissions are an important correlate of wealth, at least at present. Wealth, as measured by per capita income (i.e., income per head of population), varies widely between different countries. Activities of the poor that involve emissions of GHGs are often associated with basic needs, such as heating to stay tolerably warm. In richer countries, emissions tend to be associated with things like cars, central heating, etc.

Physiological and biochemical effects on biota avoidance and adaptation mechanisms in plants and animals

One of the effect of Climate change is drought. It is considered as chronic disaster. Due to increase in drought the farmers has to depend on ground water for agriculture. 

Na+ exclusion

In the majority of plant species grown under salinity, Na+ appears to reach a toxic concentration before Cl− does, and so most studies have concentrated on Na+ exclusion and the control of Na+ transport within the plant. Therefore, another essential mechanism of tolerance involves the ability to reduce the ionic stress on the plant by minimizing the amount of Na+ that accumulates in the cytosol of cells, particularly those in the transpiring leaves. This process, as well as tissue tolerance, involves up- and down regulation of the expression of specific ion channels and transporters, allowing the control of Na+ transport throughout the plant. Na+ exclusion from leaves is associated with salt tolerance in cereal crops including rice, durum wheat, bread wheat and barley.

 Exclusion of Na+ from the leaves is due to low net Na+ uptake by cells in the root cortex and the tight control of net loading of the xylem by parenchyma cells in the stele. Na+ exclusion by roots ensures that Na+ does not accumulate to toxic concentrations within leaf blades. A failure in Na+ exclusion manifests its toxic effect after days or weeks, depending on the species, and causes premature death of older leaves. An efficient cytosolic Na+ exclusion is also got through operation of vacuolar Na+/H+ antiports that move potentially harmful ions from cytosol into large, internally acidic, tonoplast-bound vacuoles. These ions, in turn, act as an osmoticum within the vacuole, which then maintain water flow into the cell, thus allowing plants to grow in soils containing high salinity.

Durum wheat is a salt-sensitive species and germination and seedling stages are the most critical phases for plant growth under salinity. Its sensitivity to salt stress is higher than bread wheat, due to a poor ability to exclude Na+ from the leaf blades, and a lack of the K+/Na+ discrimination character displayed by bread wheat.

The mechanism of Na+ exclusion allows the plant to avoid or postpone the problem related to ion toxicity, but if Na+ exclusion is not compensated for by the uptake of K+, it determines a greater demand for organic solutes for osmotic adjustment. The synthesis of organic solutes jeopardizes the energy balance of the plant. Thus, the plant must cope ion toxicity on the one hand, and turgor loss on the other. The knowledge on how Na+ is sensed is still very limited in most cellular systems. Theoretically, Na+ can be sensed either before or after entering the cell, or both. Extracellular Na+ may be sensed by a membrane receptor, whereas intracellular Na+ may be sensed either by membrane proteins or by any of the many Na+-sensitive enzymes in the cytoplasm.

Tissue tolerance

The third mechanism, tissue tolerance entails an increase of survival of old leaves. It requires compartmentalization of Na+ and Cl− at the cellular and intracellular level to avoid toxic concentrations within the cytoplasm, especially in mesophyll cells in the leaf and synthesis and accumulation of compatible solutes within the cytoplasm. Compatible solutes play a role in plant osmotolerance by various ways, protecting enzymes from denaturation, stabilising membrane or macromolecules or playing adaptive roles in mediating osmotic adjustment. The function of the compatible solutes is not limited to osmotic balance.

Compatible solutes are typically hydrophilic, and may be able to replace water at the surface of proteins or membranes, thus acting as low molecular weight chaperones. These solutes also function to protect cellular structures through scavenging. Compatible solutes are small molecules, water soluble and uniformly neutral with respect to the perturbation of cellular functions, even when present at high concentrations. They comprise nitrogen containing compounds such as amino acids, amines and betaines, but also organic acids, sugars and polyols

Water stress during the production phase of some fruits and vegetables may affect their physiology and morphology in such a manner as to influence susceptibility to weight loss in storage. There have been both positive effects reported for field water deficits (stress) in tree fruits and root vegetables. In the case of peaches, it has been shown that lower levels of irrigation results in higher density of fruit surface trichomes and consequent lower weight losses in storage.

Deficit irrigation of apples and pears could reduce water loss of these fruit in subsequent storage and this was attributed to reduction in skin permeance of the deficit irrigated fruit. Presumably, fruit grown under moderate water stresses imposed by deficit irrigation practices adapt by developing a less water permeable cuticle. In terms of understanding that water deficits can have negative effects on postharvest stress susceptibility, irrigation of apples has been shown to enhance apple size which was associated with lower to water losses during storage. This observation highlights a main concern about using deficit irrigationn, which is the reduced size of fruit.

Metabolic changes Induced by stress

Heat stress induces metabolic changes associated with heat shock protein accumulations which are known to confer persistent levels of stress resistance in heat-exposed produce. Heat stress can also inhibit the production and accumulation of lycopene. The duration and temperature of exposure will determine if such an effect will occur, but tomato fruit exposed to 32°C continuously will not turn red, remaining yellow even at full ripeness.

Regarding plants, higher atmospheric CO₂ levels tend to reduce stomatal conductance and transpiration, thereby lowering latent heat loss and causing higher leaf temperatures. Thus, in the future, plants will likely experience increases in acute heat and drought stress, which can impact ecosystem productivity

DNA is a chemical structure made of molecules (called ‘nucleotides’). Like all chemicals changes in its environment change it. Any environmental quality - examples include: temperature, radiation (incl. sunlight), other chemicals, or mechanical activity (wind, or chewing insects, or grazing gnus, or trampling elephants, bison, ATVs, or concert-goers).

The universe - and this insignificant planet almost on the tattered fringe of a pretty average galaxy in a normal galactic cluster - is made up in its entirety of matter (+ ‘dark’ matter) and energy (+ ‘dark’ energy). Our planet (environment) consists, therefore, entirely of chemicals and chemical reactions.

So, changes in ‘the environment’ are really simply changes in chemical status - which unavoidably impact other parts of that environment chemically. Enough change of a particular sort may alter the molecules in its vicinity. Alterations in the DNA molecule are special - because of the special activities DNA evolved to perform. DNA evolved as an information storage system - when DNA is altered information is altered - that information being the design protocol for a specific life-form. The result is an alteration in the resulting individual. That alteration can be for better or worse - can aid viability or reduce it.

In humans, for an instance, well under half all fertilised eggs survive the womb (it’s an environment) - some combination of their makeup and the environment chemically aborts them - naturally. I use that example because uteri evolved as hospitable environments for fertilised eggs - but some eggs can’t thrive in utero. All because of an incompatibility of that chemical packet of genetic information with the uterine environment.

The chemical essence of all biological processes is why a good grounding in the science of organic chemistry (the ‘organic’ bit referring to ‘Carbon’ - since that is what terrestrial lifeforms are based upon) is useful (if not absolutely necessary) when trying to understand virtually any aspect of biological science.

 

Ten species that are evolving due to changing climate

Corals

Corals are highly sensitive to temperature changes in the ocean. Higher temperatures can cause bleaching, when corals spit out the colorful algae that live inside their tissues. Algae give corals nutrients in exchange for shelter, so bleaching can be a death sentence, especially for species in stressful, low-nutrient environments. Coral populations might be shifting to favor corals with algae that are less sensitive to bleaching.

On Ofu Island in American Samoa, A. hyacinthus lives in both hot and cool pools. The table corals (Acropora hyacinthus) can adapt to resist bleaching in warmer waters. Only 20 percent of corals from the hot pools bleached, compared to 55 percent from the cool pools.

Thyme

Varieties of Mediterranean thyme (Thymus vulgaris) produce oils with different chemical compositions, and the ones with stronger smelling compounds like phenols are more effective at deterring herbivores. Producing phenols typically comes at a cost, though, as these plants are more sensitive to freezing. But in southern France’s Saint-Martin-de-Londres basin, winters are getting warmer. Since the 1970s, the basin has seen fewer freezing nights during the cold season.

Looking at 24 populations across the basin in 1974 versus 2010, found an increase in the proportion of plants that produce phenolic compounds. These plants are even popping up in areas where they didn’t grow in the 1970s. Since the plant’s genes determine the chemical composition of its oils, it’s likely that genetic changes are behind wild thyme’s response to warmer winters.

Pink Salmon

Environmental factors often drive migratory behavior patterns in animals. For salmon, migration is crucial to their survival as a species, because the fish swim from the ocean and up freshwater streams to spawn. The need to migrate is so strong it is even written into their genes. In Auke Creek, Alaska, one pink salmon (Oncorhynchus gorbuscha) population is migrating about two weeks earlier than it was 40 years ago. So scientists looked at both genetic and migratory data over 32 years to see if genetic changes were behind the switch.

Tawny Owls

A common nocturnal predator in the temperate forests of Europe, tawny owls (Strix aluco) come in two basic shades: brown and less brown. No matter their sex or age, an owl’s feather color depends entirely on how much of a pigment called pheomelanin ends up in its plumage, something that is dictated by a variety of genes. Though regular brown is the dominant trait, the pale brown or grayish color helps some owls blend in with snowy trees and hide from predators. More snow typically equals more gray owls.

With milder winters in Finland, one population of tawny owls showed a significant uptick in brown-plumed owls over the last 28 years. A nationwide increase in brown owls over the last 48 years was noticed. It makes sense that natural selection might favor brown coloration: With less snow, brown owls are better at blending in with the surrounding forest, giving those birds a better chance to survive and reproduce.

Pitcher Plant Mosquitoes

In the bogs of eastern North America, the larvae of pitcher plant mosquitoes (Wyeomyia smithii) hibernate in winter and blossom into fully grown adults come spring, when they thrive on the nectar inside their namesake plants. As the days grow shorter, the mosquitoes are genetically programmed to hibernate. Mosquitos at the southern end of the species’ range had already adapted to delay hibernation based on the longer growing season. But now northern populations are also hibernating later as global temperatures rise. Asian tiger mosquito, a carrier of West Nile virus, and the water strider are experiencing similar shifts in hibernation periods based on seasonal impacts of climate change.

Banded Snails

For banded snails (Cepaea nemoralis), shell coloration is determined not only by genes, but also by body temperature: Snails with light shells tend to be cooler.  Warmer temperatures in Europe might make the lighter coloration become more prevalent.

 

 

Sockeye Salmon

In the Columbia River, sockeye salmon (Oncorhynchus nerka) are migrating earlier every year in the spring and early summer to spawn.  Evolution in response to higher water temperatures proved the most likely explanation for about two-thirds of the shift, while individual adaptation to river flow changes could explain the rest.

Red Squirrels

The southwest Yukon has seen increasingly warm springs and a drier environment, encouraging white spruce trees to produce more cones—and giving North American red squirrels (Tamiasciurus hudsonicus) more to eat. In red squirrels, the more cones females eat in the fall, the earlier they give birth. Individual population of red squirrels near Kluane Lake, Canada, shift to earlier birthing times of almost 2 days per year over the last 10 years.

Fruit Flies

Species can vary a lot based on their geography. In the case of the common fruit fly (Drosophila melanogaster), genetic variants correspond to populations living at different latitudes, and specific enzyme mutations can serve as biomarkers. Southern Australia is more temperate and tropical, while northern Australia is dry and hot. Many fruit flies living in Southern Australia now have the genetic mutations common in more northern populations—as if they’d moved nearly 4 degrees in latitude. These changes are linked to coping with a warmer and drier climate. similar trends also found in Europe and North America

Great Tits

Sometimes organisms are slow to adapt. In Holland’s Hoge Veluwe Park, caterpillars are maturing earlier each year as spring comes earlier. But their predators, great tits (Parus major), aren’t always changing their schedule to hatch when the caterpillars are at their peak, and bird numbers are dropping. As with the hibernating mosquitoes, great tits have a genetic trigger that spurs them to lay eggs when spring arrives. But there’s some variation in how much an individual bird can tweak its egg-laying date in response to an earlier spring. Greater genetic selection for birds could vary their egg-laying time to match the caterpillars' arrival. If this trend continues, it could save them from decline.