168-632: The Paris Agreement (also called the Paris Accords or Paris Climate Accords ) is an international treaty on climate change that was signed in 2016. The treaty covers climate change mitigation , adaptation , and finance . The Paris Agreement was negotiated by 196 parties at the 2015 United Nations Climate Change Conference near Paris , France. As of February 2023, 195 members of the United Nations Framework Convention on Climate Change (UNFCCC) are parties to
336-658: A sustainable manner. The UNFCCC's work currently focuses on implementing the Paris Agreement . This agreement entered into force in 2016. It aims to limit the rise in global temperature to well below 2 °C (3.6 °F) above levels before the Industrial Revolution , and even aiming to hold it at 1.5 °C (2.7 °F). The Paris Agreement superseded the UNFCCC's Kyoto Protocol which had been signed in 1997 and ran from 2005 to 2020. By 2022,
504-623: A bottom-up structure, as its core pledge and review mechanism allows nations to set their own nationally determined contributions (NDCs), rather than having targets imposed top down. Unlike its predecessor, the Kyoto Protocol, which sets commitment targets that have legal force, the Paris Agreement, with its emphasis on consensus building , allows for voluntary and nationally determined targets. The specific climate goals are thus politically encouraged, rather than legally bound. Only
672-680: A building on the UN Campus known as Langer Eugen . The secretariat is established under Article 8 of the Convention and headed by the Executive Secretary. The secretariat, augmented through the parallel efforts of the Intergovernmental Panel on Climate Change (IPCC), aims to gain consensus through meetings and the discussion of various strategies. Since the signing of the UNFCCC treaty, Conferences of
840-481: A country wants to use more cost-effective cooperative approaches to achieve their NDCs, they will have to monitor carbon units for their economies. So far, as the only country who wants to buy ITMOs, Switzerland has signed deals regarding ITMO tradings with Peru, Ghana, Senegal, Georgia, Dominica, Vanuatu, Thailand and Ukraine. Paragraphs 6.4 –6.7 establish a mechanism "to contribute to the mitigation of greenhouse gases and support sustainable development". Though there
1008-642: A decadal timescale. Other changes are caused by an imbalance of energy from external forcings . Examples of these include changes in the concentrations of greenhouse gases , solar luminosity , volcanic eruptions, and variations in the Earth's orbit around the Sun. To determine the human contribution to climate change, unique "fingerprints" for all potential causes are developed and compared with both observed patterns and known internal climate variability . For example, solar forcing—whose fingerprint involves warming
1176-504: A gain of emission units for one party and a reduction of emission units for the other, a so called "corresponding adjustment". Because the NDCs, and domestic carbon trading schemes, are heterogeneous, the ITMOs will provide a format for global linkage under the auspices of the UNFCCC. The provision thus also creates a pressure for countries to adopt emissions management systems – if
1344-542: A lot of light to being dark after the ice has melted, they start absorbing more heat . Local black carbon deposits on snow and ice also contribute to Arctic warming. Arctic surface temperatures are increasing between three and four times faster than in the rest of the world. Melting of ice sheets near the poles weakens both the Atlantic and the Antarctic limb of thermohaline circulation , which further changes
1512-508: A low-emission development strategy is central to sustainable development, and that the share of global emissions originating in developing countries will grow to meet their social and development needs. The UN Sustainable Development Goal 13 (SDG 13) includes a target about the UNFCCC and explains how the Green Climate Fund is meant to be used: One of the five targets under SDG 13, meant to be achieved by 2030, states: "Implement
1680-412: A marked increase in temperature. Ongoing changes in climate have had no precedent for several thousand years. Multiple independent datasets all show worldwide increases in surface temperature, at a rate of around 0.2 °C per decade. The 2014–2023 decade warmed to an average 1.19 °C [1.06–1.30 °C] compared to the pre-industrial baseline (1850–1900). Not every single year was warmer than
1848-635: A measurable, reportable and verifiable manner." 42 developed countries have submitted mitigation targets to the UNFCCC secretariat, as have 57 developing countries and the African Group (a group of countries within the UN). As part of the 2009 Copenhagen negotiations, a number of countries produced the Copenhagen Accord. The Accord states that global warming should be limited to below 2.0 °C (3.6 °F). The Accord does not specify what
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#17327652702462016-409: A new commitment of at least $ 100 billion per year has to be agreed before 2025. Climate change Present-day climate change includes both global warming —the ongoing increase in global average temperature —and its wider effects on Earth's climate . Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures
2184-408: A physical climate model. These models simulate how population, economic growth , and energy use affect—and interact with—the physical climate. With this information, these models can produce scenarios of future greenhouse gas emissions. This is then used as input for physical climate models and carbon cycle models to predict how atmospheric concentrations of greenhouse gases might change. Depending on
2352-613: A report on global warming of 1.5 °C. The IPCC subsequently released the Special Report on Global Warming of 1.5 °C (SR15) in 2018. The report showed that it was possible to keep warming below 1.5 °C during the 21st century. But this would mean deep cuts in emissions. It would also mean rapid, far-reaching changes in all aspects of society. The report showed warming of 2 °C would have much more severe impacts than 1.5 °C. In other words: every bit of warming matters. SR15 had an unprecedented impact for an IPCC report in
2520-602: A report released in 2022 the IPCC promotes the need for innovation and technological changes in combination with consumption and production behavioral changes to meet Paris Agreement objectives. To stay below 1.5 °C of global warming, emissions need to be cut by roughly 50% by 2030. This is an aggregate of each country's nationally determined contributions . By mid-century, CO 2 emissions would need to be cut to zero, and total greenhouse gases would need to be net zero just after mid-century. There are barriers to implementing
2688-410: A result of climate change. Global sea level is rising as a consequence of thermal expansion and the melting of glaciers and ice sheets . Sea level rise has increased over time, reaching 4.8 cm per decade between 2014 and 2023. Over the 21st century, the IPCC projects 32–62 cm of sea level rise under a low emission scenario, 44–76 cm under an intermediate one and 65–101 cm under
2856-474: A result. The World Health Organization calls climate change one of the biggest threats to global health in the 21st century. Societies and ecosystems will experience more severe risks without action to limit warming . Adapting to climate change through efforts like flood control measures or drought-resistant crops partially reduces climate change risks, although some limits to adaptation have already been reached. Poorer communities are responsible for
3024-417: A small share of global emissions , yet have the least ability to adapt and are most vulnerable to climate change . Many climate change impacts have been observed in the first decades of the 21st century, with 2023 the warmest on record at +1.48 °C (2.66 °F) since regular tracking began in 1850. Additional warming will increase these impacts and can trigger tipping points , such as melting all of
3192-505: A specific date, nor to meet their targets. There will be only a name and shame system or as János Pásztor , the former U.N. assistant secretary-general on climate change, stated, a "name and encourage" plan. Under the Paris Agreement, countries must increase their ambition every five years. To facilitate this, the agreement established the Global Stocktake , which assesses progress, with the first evaluation in 2023. The outcome
3360-466: A specific division between developed and developing nations. Countries determine themselves what contributions they should make to achieve the aims of the treaty. As such, these plans are called nationally determined contributions (NDCs). Article 3 requires NDCs to be "ambitious efforts" towards "achieving the purpose of this Agreement" and to "represent a progression over time". The contributions should be set every five years and are to be registered by
3528-548: A very high emission scenario. Marine ice sheet instability processes in Antarctica may add substantially to these values, including the possibility of a 2-meter sea level rise by 2100 under high emissions. Climate change has led to decades of shrinking and thinning of the Arctic sea ice . While ice-free summers are expected to be rare at 1.5 °C degrees of warming, they are set to occur once every three to ten years at
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#17327652702463696-519: A warming level of 2 °C. Higher atmospheric CO 2 concentrations cause more CO 2 to dissolve in the oceans, which is making them more acidic . Because oxygen is less soluble in warmer water, its concentrations in the ocean are decreasing , and dead zones are expanding. Greater degrees of global warming increase the risk of passing through ' tipping points '—thresholds beyond which certain major impacts can no longer be avoided even if temperatures return to their previous state. For instance,
3864-440: Is driven by human activities , especially fossil fuel burning since the Industrial Revolution . Fossil fuel use, deforestation , and some agricultural and industrial practices release greenhouse gases . These gases absorb some of the heat that the Earth radiates after it warms from sunlight , warming the lower atmosphere. Carbon dioxide , the primary greenhouse gas driving global warming, has grown by about 50% and
4032-622: Is a binding agreement, but many of its articles do not imply obligations or are there to facilitate international collaboration. It covers most greenhouse gas emissions, but does not apply to international aviation and shipping , which fall under the responsibility of the International Civil Aviation Organization and the International Maritime Organization , respectively. The Paris Agreement has been described as having
4200-564: Is an estimated total sea level rise of 2.3 metres per degree Celsius (4.2 ft/°F) after 2000 years. Oceanic CO 2 uptake is slow enough that ocean acidification will also continue for hundreds to thousands of years. Deep oceans (below 2,000 metres (6,600 ft)) are also already committed to losing over 10% of their dissolved oxygen by the warming which occurred to date. Further, the West Antarctic ice sheet appears committed to practically irreversible melting, which would increase
4368-488: Is at levels not seen for millions of years. Climate change has an increasingly large impact on the environment . Deserts are expanding , while heat waves and wildfires are becoming more common. Amplified warming in the Arctic has contributed to thawing permafrost , retreat of glaciers and sea ice decline . Higher temperatures are also causing more intense storms , droughts, and other weather extremes . Rapid environmental change in mountains , coral reefs , and
4536-711: Is determined by modelling the carbon cycle and climate sensitivity to greenhouse gases. According to UNEP , global warming can be kept below 1.5 °C with a 50% chance if emissions after 2023 do not exceed 200 gigatonnes of CO 2 . This corresponds to around 4 years of current emissions. To stay under 2.0 °C, the carbon budget is 900 gigatonnes of CO 2 , or 16 years of current emissions. The climate system experiences various cycles on its own which can last for years, decades or even centuries. For example, El Niño events cause short-term spikes in surface temperature while La Niña events cause short term cooling. Their relative frequency can affect global temperature trends on
4704-466: Is guided by specific objectives that, together, are seen as crucial for effectively implementing climate adaptation and mitigation actions, and for achieving the ultimate objective of the UNFCCC. The Kyoto Protocol ( Japanese : 京都議定書 , Hepburn : Kyōto Giteisho ) was an international treaty which extended the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions , based on
4872-521: Is implemented via national policy. It would involve improvements to energy efficiency to decrease the energy intensity of the global economy. Implementation also requires fossil fuel burning to be cut back and the share of sustainable energy to grow rapidly. Emissions are being reduced rapidly in the electricity sector, but not in the building, transport and heating sector. Some industries are difficult to decarbonize, and for those carbon dioxide removal may be necessary to achieve net zero emissions . In
5040-399: Is independent of where greenhouse gases are emitted, because the gases persist long enough to diffuse across the planet. Since the pre-industrial period, the average surface temperature over land regions has increased almost twice as fast as the global average surface temperature. This is because oceans lose more heat by evaporation and oceans can store a lot of heat . The thermal energy in
5208-806: Is intended that the Green Climate Fund be the centrepiece of efforts to raise climate finance under the UNFCCC. There are four other, smaller multilateral climate funds for paying out money in climate finance which are coordinated by the UNFCCC. These include the Adaptation Fund (AF), the Least Developed Countries Fund (LDCF), the Special Climate Change Fund (SCCF) and the Global Environment Facility (GEF). The GCF
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5376-740: Is no official name for the mechanism as yet, it has been referred to as the Sustainable Development Mechanism or SDM. The SDM is considered to be the successor to the Clean Development Mechanism , a mechanism under the Kyoto Protocol by which parties could collaboratively pursue emissions reductions. The SDM is set to largely resemble the Clean Development Mechanism, with the dual goal of contributing to global GHG emissions reductions and supporting sustainable development. Though
5544-470: Is not strict enough. There is debate about the effectiveness of the agreement. While pledges under the Paris Agreement are insufficient for reaching the set temperature goals, there is a mechanism of increased ambition . The Paris Agreement has been successfully used in climate litigation forcing countries and an oil company to strengthen climate action. The aim of the agreement, as described in Article 2,
5712-520: Is not threatened and to enable economic development to proceed in a sustainable manner". Action for Climate Empowerment (ACE) is a term adopted by the UNFCCC in 2015 to have a better name for this topic than "Article 6". It refers to Article 6 of the convention's original text (1992), focusing on six priority areas: education, training, public awareness, public participation, public access to information, and international cooperation on these issues. The implementation of all six areas has been identified as
5880-564: Is possible that the SDM will see difficulties. Climate change adaptation received more focus in Paris negotiations than in previous climate treaties. Collective, long-term adaptation goals are included in the agreement, and countries must report on their adaptation actions, making it a parallel component with mitigation. The adaptation goals focus on enhancing adaptive capacity , increasing resilience , and limiting vulnerability. The Paris Agreement
6048-450: Is primarily attributed to sulfate aerosols produced by the combustion of fossil fuels with heavy sulfur concentrations like coal and bunker fuel . Smaller contributions come from black carbon (from combustion of fossil fuels and biomass), and from dust. Globally, aerosols have been declining since 1990 due to pollution controls, meaning that they no longer mask greenhouse gas warming as much. Aerosols also have indirect effects on
6216-409: Is problematic that key signatory states are not adhering to their individual commitments. For this reason, the UNFCCC has been criticized as being unsuccessful in reducing greenhouse gas emission since its adoption. Parties to the convention have not agreed on a process allowing for majority voting. All decisions are taken by consensus, giving individual parties or countries a veto. The effectiveness of
6384-690: Is put towards climate action . The Fund's former director Héla Cheikhrouhou has complained in 2016 that the Fund is backing too many "business-as-usual types of investment proposals". This view is echoed by a number of civil society organizations. "UNFCCC" is also the name of the Secretariat charged with supporting the operation of the convention, with offices on the UN Campus in Bonn, Germany . Offices were formerly located in Haus Carstanjen and in
6552-444: Is radiating into space. Warming reduces average snow cover and forces the retreat of glaciers . At the same time, warming also causes greater evaporation from the oceans , leading to more atmospheric humidity , more and heavier precipitation . Plants are flowering earlier in spring, and thousands of animal species have been permanently moving to cooler areas. Different regions of the world warm at different rates . The pattern
6720-516: Is shaped by feedbacks, which either amplify or dampen the change. Self-reinforcing or positive feedbacks increase the response, while balancing or negative feedbacks reduce it. The main reinforcing feedbacks are the water-vapour feedback , the ice–albedo feedback , and the net effect of clouds. The primary balancing mechanism is radiative cooling , as Earth's surface gives off more heat to space in response to rising temperature. In addition to temperature feedbacks, there are feedbacks in
6888-588: Is the "Amounts provided and mobilized in United States dollars per year in relation to the continued existing collective mobilization goal of the $ 100 billion commitment through to 2025". The Green Climate Fund (GCF) is a fund for climate finance that was established within the framework of the United Nations Framework Convention on Climate Change (UNFCCC). Considered the world's largest fund of its kind, GCF's objective
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7056-545: Is the UN process for negotiating an agreement to limit dangerous climate change. It is an international treaty among countries to combat "dangerous human interference with the climate system ". The main way to do this is limiting the increase in greenhouse gases in the atmosphere. It was signed in 1992 by 154 states at the United Nations Conference on Environment and Development (UNCED), informally known as
7224-593: Is the largest of these five funds. As of Dec 2023, the GCF had a portfolio of 13.5 billion USD (51.9 billion USD including co-financing). The process of designing the GCF has raised several issues. These include ongoing questions on how funds will be raised, the role of the private sector, the level of "country ownership" of resources, and the transparency of the Board itself. Also, this additional international climate institution might further fragment taxpayer's money that
7392-407: Is the major reason why different climate models project different magnitudes of warming for a given amount of emissions. A climate model is a representation of the physical, chemical and biological processes that affect the climate system. Models include natural processes like changes in the Earth's orbit, historical changes in the Sun's activity, and volcanic forcing. Models are used to estimate
7560-561: Is to assist developing countries with climate change adaptation and mitigation activities. The GCF is an operating entity of the financial mechanism of the UNFCCC. It is based in Songdo , Incheon , South Korea. It is governed by a Board of 24 members and supported by a Secretariat. Mafalda Duarte , a Portuguese development economist, is the Fund's Executive Director. The Green Climate Fund supports projects and other activities in developing countries using thematic funding windows . It
7728-452: Is to be used as input for new nationally determined contributions of parties. The Talanoa Dialogue in 2018 was seen as an example for the global stocktake. After a year of discussion, a report was published and there was a call for action, but countries did not increase ambition afterwards. The stocktake works as part of the Paris Agreement's effort to create a "ratcheting up" of ambition in emissions cuts. Because analysts agreed in 2014 that
7896-434: Is to have a stronger response to the danger of climate change; it seeks to enhance the implementation of the United Nations Framework Convention on Climate Change through: (a) Holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels, recognizing that this would significantly reduce
8064-417: Is unclear. A related phenomenon driven by climate change is woody plant encroachment , affecting up to 500 million hectares globally. Climate change has contributed to the expansion of drier climate zones, such as the expansion of deserts in the subtropics . The size and speed of global warming is making abrupt changes in ecosystems more likely. Overall, it is expected that climate change will result in
8232-511: The Atlantic meridional overturning circulation (AMOC), and irreversible damage to key ecosystems like the Amazon rainforest and coral reefs can unfold in a matter of decades. The long-term effects of climate change on oceans include further ice melt, ocean warming , sea level rise, ocean acidification and ocean deoxygenation. The timescale of long-term impacts are centuries to millennia due to CO 2 's long atmospheric lifetime. The result
8400-693: The Earth Summit , held in Rio de Janeiro . The treaty entered into force on 21 March 1994. "UNFCCC" is also the name of the Secretariat charged with supporting the operation of the convention, with offices on the UN Campus in Bonn , Germany. The convention's main objective is explained in Article 2. It is the "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [i.e., human-caused] interference with
8568-661: The Earth's energy budget . Sulfate aerosols act as cloud condensation nuclei and lead to clouds that have more and smaller cloud droplets. These clouds reflect solar radiation more efficiently than clouds with fewer and larger droplets. They also reduce the growth of raindrops , which makes clouds more reflective to incoming sunlight. Indirect effects of aerosols are the largest uncertainty in radiative forcing . While aerosols typically limit global warming by reflecting sunlight, black carbon in soot that falls on snow or ice can contribute to global warming. Not only does this increase
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#17327652702468736-573: The Greenland ice sheet is already melting, but if global warming reaches levels between 1.7 °C and 2.3 °C, its melting will continue until it fully disappears. If the warming is later reduced to 1.5 °C or less, it will still lose a lot more ice than if the warming was never allowed to reach the threshold in the first place. While the ice sheets would melt over millennia, other tipping points would occur faster and give societies less time to respond. The collapse of major ocean currents like
8904-840: The Greenland ice sheet . Under the 2015 Paris Agreement , nations collectively agreed to keep warming "well under 2 °C". However, with pledges made under the Agreement, global warming would still reach about 2.8 °C (5.0 °F) by the end of the century. Limiting warming to 1.5 °C would require halving emissions by 2030 and achieving net-zero emissions by 2050. Fossil fuel use can be phased out by conserving energy and switching to energy sources that do not produce significant carbon pollution. These energy sources include wind , solar , hydro , and nuclear power . Cleanly generated electricity can replace fossil fuels for powering transportation , heating buildings , and running industrial processes. Carbon can also be removed from
9072-635: The Industrial Revolution , naturally-occurring amounts of greenhouse gases caused the air near the surface to be about 33 °C warmer than it would have been in their absence. Human activity since the Industrial Revolution, mainly extracting and burning fossil fuels ( coal , oil , and natural gas ), has increased the amount of greenhouse gases in the atmosphere. In 2022, the concentrations of CO 2 and methane had increased by about 50% and 164%, respectively, since 1750. These CO 2 levels are higher than they have been at any time during
9240-631: The Montreal Protocol ) at 1990 levels, by 2000. The ultimate objective of the Framework Convention is specified in Article 2: "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [i.e., human-caused] interference with the climate system". Article 2 of the convention says this "should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production
9408-682: The Nationally Determined Contributions , and may bring down temperatures by a further 0.5°C. With initial pledges by countries inadequate, faster and more expensive future mitigation would be needed to still reach the targets. Furthermore, there is a gap between pledges by countries in their NDCs and implementation of these pledges; one third of the emission gap between the lowest-costs and actual reductions in emissions would be closed by implementing existing pledges. A pair of studies in Nature found that as of 2017 none of
9576-567: The Trump administration delivered an official notice to the United Nations that the United States, the second largest emitter of greenhouse gases after China, intended to withdraw from the Paris Agreement as soon as it was eligible to do so. The notice of withdrawal could not be submitted until the agreement was in force for three years for the US, on 4 November 2019. The U.S. government deposited
9744-519: The UNFCCC Secretariat . Each further ambition should be more ambitious than the previous one, known as the principle of progression . Countries can cooperate and pool their nationally determined contributions. The Intended Nationally Determined Contributions pledged during the 2015 Climate Change Conference are converted to NDCs when a country ratifies the Paris Agreement, unless they submit an update. The Paris Agreement does not prescribe
9912-487: The United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro (known by its popular title, the Earth Summit ). On 12 June 1992, 154 nations signed the UNFCCC, which upon ratification committed signatories' governments to reduce atmospheric concentrations of greenhouse gases with the goal of "preventing dangerous anthropogenic interference with Earth's climate system". This commitment would require substantial reductions in greenhouse gas emissions (see
10080-518: The World Economic Forum , 14.5 million more deaths are expected due to climate change by 2050. 30% of the global population currently live in areas where extreme heat and humidity are already associated with excess deaths. By 2100, 50% to 75% of the global population would live in such areas. While total crop yields have been increasing in the past 50 years due to agricultural improvements, climate change has already decreased
10248-414: The carbon cycle . While plants on land and in the ocean absorb most excess emissions of CO 2 every year, that CO 2 is returned to the atmosphere when biological matter is digested, burns, or decays. Land-surface carbon sink processes, such as carbon fixation in the soil and photosynthesis, remove about 29% of annual global CO 2 emissions. The ocean has absorbed 20 to 30% of emitted CO 2 over
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#173276527024610416-411: The climate system ". The treaty calls for continuing scientific research into the climate. This research supports meetings and negotiations to lead to agreements. The aim is to allow ecosystems to adapt to climate change . At the same time it aims to ensure there are no threats to food production from climate change or measures to address it. And it aims to enable economic development to proceed in
10584-402: The climate system . Solar irradiance has been measured directly by satellites , and indirect measurements are available from the early 1600s onwards. Since 1880, there has been no upward trend in the amount of the Sun's energy reaching the Earth, in contrast to the warming of the lower atmosphere (the troposphere ). The upper atmosphere (the stratosphere ) would also be warming if the Sun
10752-971: The extinction of many species. The oceans have heated more slowly than the land, but plants and animals in the ocean have migrated towards the colder poles faster than species on land. Just as on land, heat waves in the ocean occur more frequently due to climate change, harming a wide range of organisms such as corals, kelp , and seabirds . Ocean acidification makes it harder for marine calcifying organisms such as mussels , barnacles and corals to produce shells and skeletons ; and heatwaves have bleached coral reefs . Harmful algal blooms enhanced by climate change and eutrophication lower oxygen levels, disrupt food webs and cause great loss of marine life. Coastal ecosystems are under particular stress. Almost half of global wetlands have disappeared due to climate change and other human impacts. Plants have come under increased stress from damage by insects. The effects of climate change are impacting humans everywhere in
10920-439: The international transfer of mitigation outcomes (ITMOs). The agreement recognizes the rights of parties to use emissions reductions outside of their own borders toward their NDC, in a system of carbon accounting and trading. This provision requires the "linkage" of carbon emissions trading systems – because measured emissions reductions must avoid "double counting", transferred mitigation outcomes must be recorded as
11088-521: The scientific consensus that global warming is occurring and that human-made CO 2 emissions are driving it. The Kyoto Protocol was adopted in Kyoto , Japan, on 11 December 1997 and entered into force on 16 February 2005. There were 192 parties ( Canada withdrew from the protocol, effective December 2012) to the Protocol in 2020. The Kyoto Protocol implemented the objective of the UNFCCC to reduce
11256-432: The socioeconomic scenario and the mitigation scenario, models produce atmospheric CO 2 concentrations that range widely between 380 and 1400 ppm. The environmental effects of climate change are broad and far-reaching, affecting oceans , ice, and weather. Changes may occur gradually or rapidly. Evidence for these effects comes from studying climate change in the past, from modelling, and from modern observations. Since
11424-405: The 18th century and 1970 there was little net warming, as the warming impact of greenhouse gas emissions was offset by cooling from sulfur dioxide emissions. Sulfur dioxide causes acid rain , but it also produces sulfate aerosols in the atmosphere, which reflect sunlight and cause global dimming . After 1970, the increasing accumulation of greenhouse gases and controls on sulfur pollution led to
11592-612: The 1950s, droughts and heat waves have appeared simultaneously with increasing frequency. Extremely wet or dry events within the monsoon period have increased in India and East Asia. Monsoonal precipitation over the Northern Hemisphere has increased since 1980. The rainfall rate and intensity of hurricanes and typhoons is likely increasing , and the geographic range likely expanding poleward in response to climate warming. Frequency of tropical cyclones has not increased as
11760-500: The 1980s, the terms global warming and climate change became more common, often being used interchangeably. Scientifically, global warming refers only to increased surface warming, while climate change describes both global warming and its effects on Earth's climate system , such as precipitation changes. Climate change can also be used more broadly to include changes to the climate that have happened throughout Earth's history. Global warming —used as early as 1975 —became
11928-478: The 1992 Earth Summit is one of the first international treaties on the topic. It stipulates that parties should meet regularly to address climate change, at the Conference of Parties or COP. It forms the foundation to future climate agreements. The Kyoto Protocol , adopted in 1997, regulated greenhouse gas reductions for a limited set of countries from 2008 to 2012. The protocol was extended until 2020 with
12096-495: The 2°C upper target of the Paris Agreement, that the probabilities of major emitters meeting their NDCs without such an increase is very low. It estimated that with current trends the probability of staying below 2 °C of warming is 5% – and 26% if NDCs were met and continued post-2030 by all signatories. As of 2020, there is little scientific literature on the topics of the effectiveness of the Paris Agreement on capacity building and adaptation, even though they feature prominently in
12264-440: The Arctic is forcing many species to relocate or become extinct . Even if efforts to minimize future warming are successful, some effects will continue for centuries. These include ocean heating , ocean acidification and sea level rise . Climate change threatens people with increased flooding , extreme heat, increased food and water scarcity, more disease, and economic loss . Human migration and conflict can also be
12432-435: The Arctic is another major feedback, this reduces the reflectivity of the Earth's surface in the region and accelerates Arctic warming . This additional warming also contributes to permafrost thawing, which releases methane and CO 2 into the atmosphere. Around half of human-caused CO 2 emissions have been absorbed by land plants and by the oceans. This fraction is not static and if future CO 2 emissions decrease,
12600-545: The CO 2 released by the chemical reactions for making cement , steel , aluminum , and fertilizer . Methane emissions come from livestock , manure, rice cultivation , landfills, wastewater, and coal mining , as well as oil and gas extraction . Nitrous oxide emissions largely come from the microbial decomposition of fertilizer . While methane only lasts in the atmosphere for an average of 12 years, CO 2 lasts much longer. The Earth's surface absorbs CO 2 as part of
12768-581: The COP 21, Laurent Fabius , argued that the implementation of the Paris Agreement could be bolstered by the adoption of a Global Pact for the Environment . The latter would define the environmental rights and duties of states, individuals and businesses. The effectiveness of the Paris Agreement to reach its climate goals is under debate, with most experts saying it is insufficient for its more ambitious goal of keeping global temperature rise under 1.5°C. Many of
12936-681: The Conference of the Parties (COP22) in Marrakesh focused on these Nationally Determined Contributions and their implementation, after the Paris Agreement entered into force on 4 November 2016. As of 2022, the UNFCCC has 198 parties including all United Nations member states , United Nations General Assembly observers the State of Palestine and the Holy See , UN non-member states Niue and
13104-427: The Conference of the Parties. Subsidiary bodies include: A "National Communication" is a type of report submitted by the countries that have ratified the United Nations Framework Convention on Climate Change (UNFCCC). Developed countries are required to submit National Communications every four years and developing countries should do so. Some Least Developed Countries have not submitted National Communications in
13272-636: The Conferences also served as the Meetings of Parties of the Kyoto Protocol (CMP) and since 2016 the Conferences also serve as Meeting of the Parties to the Paris Agreement (CMA). The first conference (COP1) was held in 1995 in Berlin. The 3rd conference (COP3) was held in Kyoto and resulted in the Kyoto protocol, which was amended during the 2012 Doha Conference (COP18, CMP 8). The COP21 (CMP11) conference
13440-422: The Convention related to financial resources and transfer of technology and will take fully into account that economic and social development and poverty eradication are the first and overriding priorities of the developing country Parties. The Convention specifies the aim of Annex I Parties was stabilizing their greenhouse gas emissions ( carbon dioxide and other anthropogenic greenhouse gases not regulated under
13608-519: The Doha Amendment in 2012. The United States decided not to ratify the Protocol, mainly because of its legally-binding nature. This, and distributional conflict, led to failures of subsequent international climate negotiations. The 2009 negotiations were intended to produce a successor treaty of Kyoto, but the negotiations collapsed and the resulting Copenhagen Accord was not legally binding and did not get adopted universally. The Accord did lay
13776-521: The EU deposited its instruments of ratification on 5 October 2016, along with seven EU member states. The EU and 194 states, totalling over 98% of greenhouse gas emissions , have ratified or acceded to the agreement. The only countries which have not ratified are some greenhouse gas emitters in the Middle East : Iran with 2% of the world total being the largest. Libya and Yemen have also not ratified
13944-604: The Earth will be able to absorb up to around 70%. If they increase substantially, it'll still absorb more carbon than now, but the overall fraction will decrease to below 40%. This is because climate change increases droughts and heat waves that eventually inhibit plant growth on land, and soils will release more carbon from dead plants when they are warmer . The rate at which oceans absorb atmospheric carbon will be lowered as they become more acidic and experience changes in thermohaline circulation and phytoplankton distribution. Uncertainty over feedbacks, particularly cloud cover,
14112-530: The European Union) on the first day it was opened for signature. As of March 2021, 194 states and the European Union have signed the agreement. The agreement would enter into force (and thus become fully effective) if 55 countries that produce at least 55% of the world's greenhouse gas emissions (according to a list produced in 2015) ratify or otherwise join the treaty. Alternative ways to join
14280-531: The Fifth Assessment Report of the IPCC and the work of the subsidiary bodies of the UNFCCC. The resulting agreement was to be adopted in 2015. Negotiations in Paris took place over a two-week span, and continued throughout the three final nights. Various drafts and proposals had been debated and streamlined in the preceding year. According to one commentator two ways in which the French increased
14448-462: The French solved the problem by changing it as a "typographical error". At the conclusion of COP21 (the 21st meeting of the Conference of the Parties), on 12 December 2015, the final wording of the Paris Agreement was adopted by consensus by the 195 UNFCCC participating member states and the European Union. Nicaragua indicated they had wanted to object to the adoption as they denounced the weakness of
14616-484: The NDCs would not limit rising temperatures below 2 °C, the global stocktake reconvenes parties to assess how their new NDCs must evolve so that they continually reflect a country's "highest possible ambition". While ratcheting up the ambition of NDCs is a major aim of the global stocktake, it assesses efforts beyond mitigation. The five-year reviews will also evaluate adaptation, climate finance provisions, and technology development and transfer. On November 30, 2023,
14784-606: The Paris Agreement and the Kyoto Protocol is their scope. The Kyoto Protocol differentiated between Annex-I , richer countries with a historical responsibility for climate change, and non-Annex-I countries, but this division is blurred in the Paris Agreement as all parties are required to submit emissions reduction plans. The Paris Agreement still emphasizes the principle of Common but Differentiated Responsibility and Respective Capabilities – the acknowledgement that different nations have different capacities and duties to climate action – but it does not provide
14952-465: The Paris Agreement as a framework for a global carbon market. Article 6 is the only important part of the agreement yet to be resolved; negotiations in 2019 did not produce a result. The topic was settled during the 2021 COP26 in Glasgow . A mechanism, the "corresponding adjustment", was established to avoid double counting for emission offsets. Paragraphs 6.2 and 6.3 establish a framework to govern
15120-428: The Paris Agreement pledges, the average temperature would rise by 2.4°C, and with every zero emission target reached, the average temperature would rise by 2.0°C. The Production Gap 2021 report states that world governments still plan to produce 110% more fossil fuels in 2030 (including 240% more coal, 57% more oil and 71% more gas) than the 1.5 degree limit. In September 2023 the first global stocktake report about
15288-405: The Paris Agreement that are yet to be set. Most NDCs have a conditional component. While the NDCs themselves are not binding, the procedures surrounding them are. These procedures include the obligation to prepare, communicate and maintain successive NDCs, set a new one every five years, and provide information about the implementation. There is no mechanism to force a country to set a NDC target by
15456-475: The Paris Agreement to reach its climate goals is also under debate, especially with regards to its more ambitious goal of keeping the global temperature rise to under 1.5 °C. The IPCC 's First Assessment Report appeared in 1990. The report gave a broad overview of climate change science and the scientific consensus to date . It discussed uncertainties and provided evidence of warming. The authors said they are certain that greenhouse gases are increasing in
15624-472: The Paris Agreement. A strong preference was reported that the EU and its 28 member states ratify at the same time to ensure that they do not engage themselves to fulfilling obligations that strictly belong to the other, and there were fears by observers that disagreement over each member state's share of the EU-wide reduction target, as well as Britain's vote to leave the EU might delay the Paris pact. However,
15792-422: The Paris Agreement. The literature available is mostly mixed in its conclusions about loss and damage, and adaptation. According to the stocktake report, the agreement has a significant effect: while in 2010 the expected temperature rise by 2100 was 3.7–4.8 °C, at COP 27 it was 2.4–2.6°C and if all countries will fulfill their long-term pledges even 1.7–2.1 °C. Despite it, the world is still very far from reaching
15960-401: The Parties (COPs) have discussed how to achieve the treaty's aims. From 2010 to 2016 the head of the secretariat was Christiana Figueres , following by Patricia Espinosa who was appointed Executive Secretary on 18 May 2016 by United Nations Secretary-General Ban Ki-moon and took office on 18 July 2016. Espinosa retired on 16 July 2022. UN Under Secretary General Ibrahim Thiaw served as
16128-965: The Parties. These include the Bali Action Plan (2007), the Copenhagen Accord (2009), the Cancún agreements (2010), and the Durban Platform for Enhanced Action (2012). As part of the Bali Action Plan, adopted in 2007, all developed country Parties have agreed to "quantified emission limitation and reduction objectives, while ensuring the comparability of efforts among them, taking into account differences in their national circumstances". Developing country Parties agreed to "[nationally] appropriate mitigation actions context of sustainable development , supported and enabled by technology, financing and capacity-building, in
16296-637: The UN Headquarters in New York. Signing of the agreement is the first step towards ratification , but it is possible to accede to the agreement without signing. It binds parties to not act in contravention of the goal of the treaty. On 1 April 2016, the United States and China, which represent almost 40% of global emissions confirmed they would sign the Paris Climate Agreement. The agreement was signed by 175 parties (174 states and
16464-1011: The UNFCCC had 198 parties. Its supreme decision-making body, the Conference of the Parties (COP) , meets every year. Other meetings at the regional and technical level take place throughout the year. The Paris Agreement mandates a review or " global stocktake " of progress towards meetings its goals every five years. The first of these took place at COP28 in the United Arab Emirates (UAE) in 2023. The treaty sets out responsibilities for three categories of states. These are developed countries , developed countries with special financial responsibilities, and developing countries . The developed countries are called Annex I countries. At first there were 38 of them. Annex I countries should adopt national policies and take corresponding measures to limit their emissions of greenhouse gases . They should also report on steps for returning individually or jointly to their 1990 greenhouse gas emission levels. It
16632-439: The UNFCCC. These plans were compiled with those made as part of the Bali Action Plan. At the 2021 annual meeting UNFCCC launched the 'UN Race-to-Zero Emissions Breakthroughs'. The aim of the campaign is to transform 20 sectors of the economy in order to achieve zero greenhouse gas emissions. At least 20% of each sector should take specific measures, and 10 sectors should be transformed before COP 26 in Glasgow. According to
16800-500: The US would "earn its way back" into legitimacy in the Paris process. United Nations Secretary-General António Guterres welcomed the return of the United States as restoring the "missing link that weakened the whole". The Paris Agreement is a short agreement with 16 introductory paragraphs and 29 articles. It contains procedural articles (covering, for example, the criteria for its entry into force) and operational articles (covering, for example, mitigation, adaptation and finance). It
16968-555: The United Nations Climate Change Conference (COP28) commenced in Dubai with renewed calls for amplified efforts towards climate action. Article 6 has been flagged as containing some of the key provisions of the Paris Agreement. Broadly, it outlines the cooperative approaches that parties can take in achieving their nationally determined carbon emissions reductions. In doing so, it helps establish
17136-457: The United Nations Framework Convention on Climate Change (UNFCCC) are parties to the agreement. Of the three UNFCCC member states which have not ratified the agreement, the only major emitter is Iran . The United States withdrew from the agreement in 2020, but rejoined in 2021. In addition to the Kyoto Protocol (and its amendment) and the Paris Agreement, parties to the Convention have agreed to further commitments during UNFCCC Conferences of
17304-441: The absorption of sunlight, it also increases melting and sea-level rise. Limiting new black carbon deposits in the Arctic could reduce global warming by 0.2 °C by 2050. The effect of decreasing sulfur content of fuel oil for ships since 2020 is estimated to cause an additional 0.05 °C increase in global mean temperature by 2050. As the Sun is the Earth's primary energy source, changes in incoming sunlight directly affect
17472-416: The acting Executive Secretary in the interim. On 15 August 2022, Secretary-General António Guterres appointed former Grenadian climate minister Simon Stiell as Executive Secretary, replacing Espinosa. Current and former executive secretaries are: The reports published by IPCC play a key role in the annual climate negotiations held by the UNFCCC. For example, the UNFCCC invited the IPCC to prepare
17640-401: The agreement . Eritrea is the latest country to ratify the agreement, on 7 February 2023. Article 28 enables parties to withdraw from the agreement after sending a withdrawal notification to the depositary . Notice can be given no earlier than three years after the agreement goes into force for the country. Withdrawal is effective one year after the depositary is notified. On 4 August 2017,
17808-414: The agreement, but were not given a chance. In the agreement the members promised to reduce their carbon output "as soon as possible" and to do their best to keep global warming " to well below 2 degrees C " (3.6 °F). The Paris Agreement was open for signature by states and regional economic integration organizations that are parties to the UNFCCC (the convention) from 22 April 2016 to 21 April 2017 at
17976-417: The agreement, each country must determine, plan, and regularly report on its contributions. No mechanism forces a country to set specific emissions targets , but each target should go beyond previous targets. In contrast to the 1997 Kyoto Protocol , the distinction between developed and developing countries is blurred, so that the latter also have to submit plans for emission reductions. The Paris Agreement
18144-423: The agreement. Of the three UNFCCC member states which have not ratified the agreement, the only major emitter is Iran . The United States withdrew from the agreement in 2020, but rejoined in 2021. The Paris Agreement has a long-term temperature goal which is to keep the rise in global surface temperature to well below 2 °C (3.6 °F) above pre-industrial levels. The treaty also states that preferably
18312-407: The agreement. Some countries struggle to attract the finance necessary for investments in decarbonization. Climate finance is fragmented, further complicating investments. Another issue is the lack of capabilities in government and other institutions to implement policy. Clean technology and knowledge is often not transferred to countries or places that need it. In December 2020, the former chair of
18480-477: The aim of the agreement: limiting temperature rise to 1.5 degrees. For doing this, emissions must peak by 2025. In September 2021, the Climate Action Tracker estimated that, with current policies, global emissions will double above the 2030 target level. The gap is 20-23 Gt CO2e. Countries such as Iran, Russia, Saudi Arabia, Singapore, and Thailand have been criticised of not doing enough to meet
18648-411: The atmosphere , for instance by increasing forest cover and farming with methods that capture carbon in soil . Before the 1980s it was unclear whether the warming effect of increased greenhouse gases was stronger than the cooling effect of airborne particulates in air pollution . Scientists used the term inadvertent climate modification to refer to human impacts on the climate at this time. In
18816-443: The atmosphere because of human activity. This is resulting in more warming of the Earth 's surface. The report led to the establishment of the United Nations Framework Convention on Climate Change (UNFCCC). The text of the Convention was produced during the meeting of an Intergovernmental Negotiating Committee in New York from 30 April to 9 May 1992. The Convention was adopted on 9 May 1992 and opened for signature on 4 June 1992 at
18984-452: The atmosphere. volcanic CO 2 emissions are more persistent, but they are equivalent to less than 1% of current human-caused CO 2 emissions. Volcanic activity still represents the single largest natural impact (forcing) on temperature in the industrial era. Yet, like the other natural forcings, it has had negligible impacts on global temperature trends since the Industrial Revolution. The climate system's response to an initial forcing
19152-568: The baseline is for these temperature targets (e.g., relative to pre-industrial or 1990 temperatures). According to the UNFCCC, these targets are relative to pre-industrial temperatures. 114 countries agreed to the Accord. The UNFCCC secretariat notes that "Some Parties ... stated in their communications to the secretariat specific understandings on the nature of the Accord and related matters, based on which they have agreed to [the Accord]." The Accord
19320-662: The basis of the Paris Agreement are shorter and less detailed but also follow a standardized structure and are subject to technical review by experts. At the 19th session of the Conference of the Parties in Warsaw in 2013, the UNFCCC created a mechanism for Intended Nationally Determined Contributions (INDCs) to be submitted in the run up to the 21st session of the Conference of the Parties in Paris (COP21) in 2015. Countries were given freedom and flexibility to ensure that these climate change mitigation and adaptation plans were nationally appropriate. This flexibility, especially regarding
19488-454: The biggest threats to global health in the 21st century. Scientists have warned about the irreversible harms it poses. Extreme weather events affect public health, and food and water security . Temperature extremes lead to increased illness and death. Climate change increases the intensity and frequency of extreme weather events. It can affect transmission of infectious diseases , such as dengue fever and malaria . According to
19656-540: The carbon cycle, such as the fertilizing effect of CO 2 on plant growth. Feedbacks are expected to trend in a positive direction as greenhouse gas emissions continue, raising climate sensitivity. These feedback processes alter the pace of global warming. For instance, warmer air can hold more moisture in the form of water vapour , which is itself a potent greenhouse gas. Warmer air can also make clouds higher and thinner, and therefore more insulating, increasing climate warming. The reduction of snow cover and sea ice in
19824-551: The climate cycled through ice ages . One of the hotter periods was the Last Interglacial , around 125,000 years ago, where temperatures were between 0.5 °C and 1.5 °C warmer than before the start of global warming. This period saw sea levels 5 to 10 metres higher than today. The most recent glacial maximum 20,000 years ago was some 5–7 °C colder. This period has sea levels that were over 125 metres (410 ft) lower than today. Temperatures stabilized in
19992-401: The commitment to mobilize $ 100 billion a year in climate finance by 2020, and agreed to continue mobilising finance at this level until 2025. The money is for supporting mitigation and adaptation in developing countries. It includes finance for the Green Climate Fund , which is a part of the UNFCCC, but also for a variety of other public and private pledges. The Paris Agreement states that
20160-471: The commitment undertaken by developed-country parties to the United Nations Framework Convention on Climate Change to a goal of mobilizing jointly $ 100 billion annually by 2020 from all sources to address the needs of developing countries in the context of meaningful mitigation actions and transparency on implementation and fully operationalize the Green Climate Fund through its capitalization as soon as possible." This target only has one indicator: Indicator 13.a
20328-684: The current interglacial period beginning 11,700 years ago . This period also saw the start of agriculture. Historical patterns of warming and cooling, like the Medieval Warm Period and the Little Ice Age , did not occur at the same time across different regions. Temperatures may have reached as high as those of the late 20th century in a limited set of regions. Climate information for that period comes from climate proxies , such as trees and ice cores . Around 1850 thermometer records began to provide global coverage. Between
20496-515: The current levels of greenhouse gases in the atmosphere. The Paris Agreement (also called the Paris Accords or Paris Climate Accords) is an international treaty on climate change that was signed in 2016. The treaty covers climate change mitigation , adaptation , and finance . The Paris Agreement was negotiated by 196 parties at the 2015 United Nations Climate Change Conference near Paris , France. As of February 2023, 195 members of
20664-403: The degree of warming future emissions will cause when accounting for the strength of climate feedbacks . Models also predict the circulation of the oceans, the annual cycle of the seasons, and the flows of carbon between the land surface and the atmosphere. The physical realism of models is tested by examining their ability to simulate current or past climates. Past models have underestimated
20832-427: The destroyed trees release CO 2 , and are not replaced by new trees, removing that carbon sink . Between 2001 and 2018, 27% of deforestation was from permanent clearing to enable agricultural expansion for crops and livestock. Another 24% has been lost to temporary clearing under the shifting cultivation agricultural systems. 26% was due to logging for wood and derived products, and wildfires have accounted for
21000-401: The distribution of heat and precipitation around the globe. The World Meteorological Organization estimates there is an 80% chance that global temperatures will exceed 1.5 °C warming for at least one year between 2024 and 2028. The chance of the 5-year average being above 1.5 °C is almost half. The IPCC expects the 20-year average global temperature to exceed +1.5 °C in
21168-444: The dominant direct influence on temperature from land use change. Thus, land use change to date is estimated to have a slight cooling effect. Air pollution, in the form of aerosols, affects the climate on a large scale. Aerosols scatter and absorb solar radiation. From 1961 to 1990, a gradual reduction in the amount of sunlight reaching the Earth's surface was observed. This phenomenon is popularly known as global dimming , and
21336-610: The early 2030s. The IPCC Sixth Assessment Report (2021) included projections that by 2100 global warming is very likely to reach 1.0–1.8 °C under a scenario with very low emissions of greenhouse gases , 2.1–3.5 °C under an intermediate emissions scenario , or 3.3–5.7 °C under a very high emissions scenario . The warming will continue past 2100 in the intermediate and high emission scenarios, with future projections of global surface temperatures by year 2300 being similar to millions of years ago. The remaining carbon budget for staying beneath certain temperature increases
21504-911: The emissions continue to increase for the rest of century, then over 9 million climate-related deaths would occur annually by 2100. Economic damages due to climate change may be severe and there is a chance of disastrous consequences. Severe impacts are expected in South-East Asia and sub-Saharan Africa , where most of the local inhabitants are dependent upon natural and agricultural resources. Heat stress can prevent outdoor labourers from working. If warming reaches 4 °C then labour capacity in those regions could be reduced by 30 to 50%. The World Bank estimates that between 2016 and 2030, climate change could drive over 120 million people into extreme poverty without adaptation. United Nations Framework Convention on Climate Change The United Nations Framework Convention on Climate Change ( UNFCCC )
21672-430: The entire atmosphere—is ruled out because only the lower atmosphere has warmed. Atmospheric aerosols produce a smaller, cooling effect. Other drivers, such as changes in albedo , are less impactful. Greenhouse gases are transparent to sunlight , and thus allow it to pass through the atmosphere to heat the Earth's surface. The Earth radiates it as heat , and greenhouse gases absorb a portion of it. This absorption slows
21840-408: The exact nature of the NDCs. At a minimum, they should contain mitigation provisions, but they may also contain pledges on adaptation, finance, technology transfer , capacity building and transparency. Some of the pledges in the NDCs are unconditional, but others are conditional on outside factors such as getting finance and technical support, the ambition from other parties or the details of rules of
22008-399: The exact provisions of the Paris Agreement have yet to be straightened out, so that it may be too early to judge effectiveness. According to the 2020 United Nations Environment Programme ( UNEP ), with the current climate commitments of the Paris Agreement, global mean temperatures will likely rise by more than 3°C by the end of the 21st century. Newer net zero commitments were not included in
22176-425: The framework for bottom-up approach of the Paris Agreement. Under the leadership of UNFCCC executive secretary Christiana Figueres , negotiation regained momentum after Copenhagen's failure. During the 2011 United Nations Climate Change Conference , the Durban Platform was established to negotiate a legal instrument governing climate change mitigation measures from 2020. The platform had a mandate to be informed by
22344-604: The global climate system has grown with only brief pauses since at least 1970, and over 90% of this extra energy has been stored in the ocean . The rest has heated the atmosphere , melted ice, and warmed the continents. The Northern Hemisphere and the North Pole have warmed much faster than the South Pole and Southern Hemisphere . The Northern Hemisphere not only has much more land, but also more seasonal snow cover and sea ice . As these surfaces flip from reflecting
22512-556: The implementation of the agreement was released. According to the report contrarily to expectations, the agreement has a significant effect: while in 2010 the expected temperature rise by 2100 was 3.7–4.8 °C, at COP 27 it was 2.4–2.6°C and if all countries will fulfill their long-term pledges 1.7–2.1 °C. However, the world remains very far from limiting warming to 1.5 degrees. To meet this benchmark, global emissions must peak by 2025, and although emissions have peaked in some countries, global emissions have not. Developed countries reaffirmed
22680-572: The last 14 million years. Concentrations of methane are far higher than they were over the last 800,000 years. Global human-caused greenhouse gas emissions in 2019 were equivalent to 59 billion tonnes of CO 2 . Of these emissions, 75% was CO 2 , 18% was methane , 4% was nitrous oxide, and 2% was fluorinated gases . CO 2 emissions primarily come from burning fossil fuels to provide energy for transport , manufacturing, heating , and electricity. Additional CO 2 emissions come from deforestation and industrial processes , which include
22848-436: The last two decades. CO 2 is only removed from the atmosphere for the long term when it is stored in the Earth's crust, which is a process that can take millions of years to complete. Around 30% of Earth's land area is largely unusable for humans ( glaciers , deserts , etc.), 26% is forests , 10% is shrubland and 34% is agricultural land . Deforestation is the main land use change contributor to global warming, as
23016-441: The last: internal climate variability processes can make any year 0.2 °C warmer or colder than the average. From 1998 to 2013, negative phases of two such processes, Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) caused a short slower period of warming called the " global warming hiatus ". After the "hiatus", the opposite occurred, with years like 2023 exhibiting temperatures well above even
23184-512: The later section, "Stabilization of greenhouse gas concentrations" ). Parties to the Convention have met annually from 1995 in Conferences of the Parties (COPs) to assess progress in dealing with climate change . Article 3(1) of the Convention states that Parties should act to protect the climate system on the basis of "common but differentiated responsibilities and respective capabilities", and that developed country Parties should "take
23352-463: The lead" in addressing climate change. Under Article 4, all Parties make general commitments to address climate change through, for example, climate change mitigation and adapting to the eventual impacts of climate change. Article 4(7) states: The extent to which developing country Parties will effectively implement their commitments under the Convention will depend on the effective implementation by developed country Parties of their commitments under
23520-481: The likelihood of success were: firstly to ensure that Intended Nationally Determined Contributions (INDCs) were completed before the start of the negotiations, and secondly to invite leaders just for the beginning of the conference. The negotiations almost failed because of a single word when the US legal team realized at the last minute that "shall" had been approved, rather than "should", meaning that developed countries would have been legally obliged to cut emissions:
23688-621: The limit of the increase should only be 1.5 °C (2.7 °F). The lower the temperature increase, the smaller the effects of climate change can be expected. To achieve this temperature goal, greenhouse gas emissions should be reduced as soon as, and by as much as, possible. They should even reach net zero by the middle of the 21st century. To stay below 1.5 °C of global warming, emissions need to be cut by roughly 50% by 2030. This figure takes into account each country's documented pledges . The treaty aims to help countries adapt to climate change effects, and mobilize enough finance. Under
23856-415: The major industrialized nations were implementing the policies they had pledged, and none met their pledged emission reduction targets, and even if they had, the sum of all member pledges (as of 2016) would not keep global temperature rise "well below 2°C". In 2021, a study using a probabilistic model concluded that the rates of emissions reductions would have to increase by 80% beyond NDCs to likely meet
24024-596: The media and with the public. It put the 1.5 °C target at the center of climate activism . The United Nations Climate Change Conference are yearly conferences held in the framework of the UNFCCC. They serve as the formal meeting of the UNFCCC Parties ( Conferences of the Parties ) (COP) to assess progress in dealing with climate change, and beginning in the mid-1990s, to negotiate the Kyoto Protocol to establish legally binding obligations for developed countries to reduce their greenhouse gas emissions. Since 2005
24192-413: The more popular term after NASA climate scientist James Hansen used it in his 1988 testimony in the U.S. Senate . Since the 2000s, climate change has increased usage. Various scientists, politicians and media may use the terms climate crisis or climate emergency to talk about climate change, and may use the term global heating instead of global warming . Over the last few million years
24360-580: The notification with the Secretary General of the United Nations and officially withdrew one year later on 4 November 2020. President Joe Biden signed an executive order on his first day in office, 20 January 2021, to re-admit the United States into the Paris Agreement. Following the 30-day period set by Article 21.3, the U.S. was readmitted to the agreement. United States Climate Envoy John Kerry took part in virtual events, saying that
24528-545: The onset of global warming by reducing greenhouse gas concentrations in the atmosphere to "a level that would prevent dangerous anthropogenic interference with the climate system" (Article 2). The Kyoto Protocol applied to the seven greenhouse gases listed in Annex A: carbon dioxide (CO 2 ) , methane (CH 4 ) , nitrous oxide (N 2 O) , hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF 6 ) , nitrogen trifluoride (NF 3 ) . Nitrogen trifluoride
24696-465: The organizers, 20% is a tipping point, after which the whole sector begins to irreversibly change. At Berlin, Cancún, and Durban, the development needs of developing country parties were reiterated. For example, the Durban Platform reaffirms that: [...] social and economic development and poverty eradication are the first and overriding priorities of developing country Parties, and that
24864-479: The past 5–15 years, largely due to capacity constraints. National Communication reports are often several hundred pages long and cover a country's measures to mitigate greenhouse gas emissions as well as a description of its vulnerabilities and impacts from climate change. National Communications are prepared according to guidelines that have been agreed by the Conference of the Parties to the UNFCCC. The (Intended) Nationally Determined Contributions (NDCs) that form
25032-549: The pivotal factor for everyone to understand and participate in solving the challenges presented by climate change. ACE calls on governments to develop and implement educational and public awareness programmes, train scientific, technical and managerial personnel, foster access to information, and promote public participation in addressing climate change and its effects. It also urges countries to cooperate in this process, by exchanging good practices and lessons learned, and strengthening national institutions. This wide scope of activities
25200-579: The processes governing the reporting and review of these goals are mandated under international law . This structure is especially notable for the United States—because there are no legal mitigation or finance targets, the agreement is considered an "executive agreement rather than a treaty". Because the UNFCCC treaty of 1992 received the consent of the US Senate, this new agreement does not require further legislation. Another key difference between
25368-619: The rate at which heat escapes into space, trapping heat near the Earth's surface and warming it over time. While water vapour (≈50%) and clouds (≈25%) are the biggest contributors to the greenhouse effect, they primarily change as a function of temperature and are therefore mostly considered to be feedbacks that change climate sensitivity . On the other hand, concentrations of gases such as CO 2 (≈20%), tropospheric ozone , CFCs and nitrous oxide are added or removed independently from temperature, and are therefore considered to be external forcings that change global temperatures. Before
25536-522: The rate of Arctic shrinkage and underestimated the rate of precipitation increase. Sea level rise since 1990 was underestimated in older models, but more recent models agree well with observations. The 2017 United States-published National Climate Assessment notes that "climate models may still be underestimating or missing relevant feedback processes". Additionally, climate models may be unable to adequately predict short-term regional climatic shifts. A subset of climate models add societal factors to
25704-622: The rate of yield growth . Fisheries have been negatively affected in multiple regions. While agricultural productivity has been positively affected in some high latitude areas, mid- and low-latitude areas have been negatively affected. According to the World Economic Forum, an increase in drought in certain regions could cause 3.2 million deaths from malnutrition by 2050 and stunting in children. With 2 °C warming, global livestock headcounts could decline by 7–10% by 2050, as less animal feed will be available. If
25872-405: The recent average. This is why the temperature change is defined in terms of a 20-year average, which reduces the noise of hot and cold years and decadal climate patterns, and detects the long-term signal. A wide range of other observations reinforce the evidence of warming. The upper atmosphere is cooling, because greenhouse gases are trapping heat near the Earth's surface, and so less heat
26040-411: The release of chemical compounds that influence clouds, and by changing wind patterns. In tropic and temperate areas the net effect is to produce significant warming, and forest restoration can make local temperatures cooler. At latitudes closer to the poles, there is a cooling effect as forest is replaced by snow-covered (and more reflective) plains. Globally, these increases in surface albedo have been
26208-476: The remaining 23%. Some forests have not been fully cleared, but were already degraded by these impacts. Restoring these forests also recovers their potential as a carbon sink. Local vegetation cover impacts how much of the sunlight gets reflected back into space ( albedo ), and how much heat is lost by evaporation . For instance, the change from a dark forest to grassland makes the surface lighter, causing it to reflect more sunlight. Deforestation can also modify
26376-460: The requirements of the agreement, and are on track to achieve a 4°C warming of the planet if current policies are implemented more widely. Of the world's countries, only the Gambia's emissions are at the level required by the Paris Agreement. Models predicted that if the necessary measures were not implemented by autumn 2021, the global average temperature would rise by 2.9°C. With the implementation of
26544-548: The risks and impacts of climate change; (b) Increasing the ability to adapt to the adverse impacts of climate change and foster climate resilience and low greenhouse gas emissions development, in a manner that does not threaten food production; (c) Making finance flows consistent with a pathway towards low greenhouse gas emissions and climate-resilient development. Countries furthermore aim to reach "global peaking of greenhouse gas emissions as soon as possible." The UN Framework Convention on Climate Change (UNFCCC), adopted at
26712-583: The sea levels by at least 3.3 m (10 ft 10 in) over approximately 2000 years. Recent warming has driven many terrestrial and freshwater species poleward and towards higher altitudes . For instance, the range of hundreds of North American birds has shifted northward at an average rate of 1.5 km/year over the past 55 years. Higher atmospheric CO 2 levels and an extended growing season have resulted in global greening. However, heatwaves and drought have reduced ecosystem productivity in some regions. The future balance of these opposing effects
26880-596: The structure and processes governing the SDM are not yet determined, certain similarities and differences from the Clean Development Mechanisms have become clear. A key difference is that the SDM will be available to all parties as opposed to only Annex-I parties , making it much wider in scope. The Clean Development Mechanism of the Kyoto Protocol was criticized for failing to produce either meaningful emissions reductions or sustainable development benefits in most instances. and for its complexity. It
27048-436: The treaty are acceptance, approval or accession. The first two are typically used when a head of state is not necessary to bind a country to a treaty, whereas the latter typically happens when a country joins a treaty already in force. After ratification by the European Union, the agreement obtained enough parties to enter into effect on 4 November 2016. Both the EU and its member states are individually responsible for ratifying
27216-400: The types of actions to be undertaken, allowed for developing countries to tailor their plans to their specific adaptation and mitigation needs, as well as towards other needs. In the aftermath of COP21, these INDCs became Nationally Determined Contributions (NDCs) as each country ratified the Paris Agreement, unless a new NDC was submitted to the UNFCCC at the same time. The 22nd session of
27384-438: The world. Impacts can be observed on all continents and ocean regions, with low-latitude, less developed areas facing the greatest risk. Continued warming has potentially "severe, pervasive and irreversible impacts" for people and ecosystems. The risks are unevenly distributed, but are generally greater for disadvantaged people in developing and developed countries. The World Health Organization calls climate change one of
27552-489: Was added for the second compliance period during the Doha Round. The Protocol was based on the principle of common but differentiated responsibilities: it acknowledged that individual countries have different capabilities in combating climate change, owing to economic development , and therefore placed the obligation to reduce current emissions on developed countries on the basis that they are historically responsible for
27720-536: Was held in Paris in 2015 and resulted in adoption of the Paris Agreement . COP28 took place in the United Arab Emirates in 2023 and included the first global stocktake under the Paris Agreement. The UAE nominated Sultan al-Jaber , who is also head of Abu Dhabi's national oil company ADNOC , to preside over COP28. Azerbaijan will host COP29 in 2024. A subsidiary body is a committee that assists
27888-494: Was not formally adopted by the Conference of the Parties. Instead, the COP "took note of the Copenhagen Accord." As part of the Accord, 17 developed country Parties and the EU-27 submitted mitigation targets, as did 45 developing country Parties. Some developing country Parties noted the need for international support in their plans. As part of the Cancún agreements, developed and developing countries submitted mitigation plans to
28056-627: Was opened for signature on 22 April 2016 ( Earth Day ) at a ceremony inside the UN Headquarters in New York . After the European Union ratified the agreement, sufficient countries had ratified the agreement responsible for enough of the world's greenhouse gases for the agreement to enter into force on 4 November 2016. World leaders have lauded the agreement. However, some environmentalists and analysts have criticized it, saying it
28224-524: Was sending more energy to Earth, but instead, it has been cooling. This is consistent with greenhouse gases preventing heat from leaving the Earth's atmosphere. Explosive volcanic eruptions can release gases, dust and ash that partially block sunlight and reduce temperatures, or they can send water vapour into the atmosphere, which adds to greenhouse gases and increases temperatures. These impacts on temperature only last for several years, because both water vapour and volcanic material have low persistence in
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