The two degree target is the international climate policy goal of limiting global warming to less than two degrees Celsius compared to pre-industrialization levels (1850–1900). It is an integral part of the Paris climate agreement. [1] This objective is a political determination based on scientific knowledge concerning the probable consequences of global warming, which dates from the Copenhagen Conference in 2009. [2] Physical climate risk scenarios, which often project to the end of the century, 2100, use the 2 °C target as a reference point. The time at which global mean temperature is predicted to reach +2 °C compared to the pre-industrial period (1850–1900) is termed the "crossing year". [3]
As a global target for limiting emissions, the 2 °C target has frequently been criticized for being higher than desirable, [1] [4] because two degrees of warming will have serious consequences for humans and the environment. [5] The IPCC Special Report on Global Warming of 1.5 °C (2018) included detailed analysis of the probable differences in impact of "limiting global warming to 1.5 °C compared with 2 °C", warning that a 2 °C temperature increase would worsen impacts that include extreme weather, Arctic sea ice decline, rising sea levels, coral bleaching, and ecosystem loss. [6]
The impact of climate change is not uniform: [7] for example, land regions tend to warm faster than ocean regions. [6] NASA has modeled predicted changes in six key climate variables: air temperature, precipitation, relative humidity, wind speed, and short- and longwave solar radiation, with particular attention to their impacts on heat stress and fire weather. NASA's NEX-GDDP-CMIP6 data set models impact at a fine-grained spatial scale, which can be used to identify key risk areas and develop adaptation and mitigation action plans for specific regions. Above the 2 °C threshold, dangerous and cascading effects are predicted to occur, with many areas experiencing simultaneous multiple impacts due to climate change. [7] [8]
As of 2022, the UN Environment Programme reported that countries have not met their climate goals to date. As a result the UN Framework Convention on Climate Change predicts a likely increase between 2.1 °C and 2.9 °C in temperature by 2100, exceeding the 2 °C climate target. [9] Some scientists suggest that the development of decarbonization technologies may offer a way to reverse the accumulation of CO2 in the atmosphere. Even if temperatures increase above 2 °C, it may become possible to halt or reverse increases by late in the century and bring CO2 levels back to the levels identified by the Paris climate agreement. [3] This type of scenario is referred to as an "overshoot pathway". [6] Achieving such an outcome will require multigenerational management over many decades. [3]
See also
References
- ^ a b Damian, Michel (18 May 2016). "Limiter le réchauffement de la planète à 1,5 °C ? La question qui brûle" [Limit global warming to 1.5 °C? The burning question]. The Conversation (in French). Retrieved 22 August 2018..
- ^ Report of the Conference of the Parties on its fifteenth session, held in Copenhagen from 7 to 19 December 2009 (PDF) (Report). United Nations Framework Convention on Climate Change. 30 March 2010. Retrieved 9 November 2022.
- ^ a b c Hannah, L.; Midgley, G.F. (13 November 2023). "30×30 for Climate: The History and Future of Climate Change–Integrated Conservation Strategies". Annual Review of Environment and Resources. 48 (1): 1–24. doi: 10.1146/annurev-environ-112321-114023. ISSN 1543-5938. Retrieved 27 November 2023.
- ^ Pérez, Eddy (13 August 2021). "Climat : le rapport du GIEC est bouleversant. Il est maintenant temps d'agir" [Climate: the IPCC report is shocking. Now is the time to act]. The Conversation (in French). Retrieved 22 August 2022..
- ^ Roberts, David (19 January 2018). "This graphic explains why 2 degrees of global warming will be way worse than 1.5". Vox. Retrieved 27 November 2023.
- ^ a b c IPCC (2018). Global Warming of 1.5 °C: IPCC Special Report on impacts of global warming of 1.5 °C above pre-industrial levels in context of strengthening response to climate change, sustainable development, and efforts to eradicate poverty (1 ed.). Cambridge University Press. doi: 10.1017/9781009157940.001. ISBN 978-1-009-15794-0.
- ^ a b "NASA Study Reveals Compounding Climate Risks at Two Degrees of Warming". Climate Change: Vital Signs of the Planet. August 14, 2023.
- ^ Park, Taejin; Hashimoto, Hirofumi; Wang, Weile; Thrasher, Bridget; Michaelis, Andrew R.; Lee, Tsengdar; Brosnan, Ian G.; Nemani, Ramakrishna R. (May 2023). "What Does Global Land Climate Look Like at 2 °C Warming?". Earth's Future. 11 (5). doi: 10.1029/2022EF003330. ISSN 2328-4277.
- ^ Hodgson, Camilla (October 27, 2022). "Climate graphic of the week: World on track for up to 2.6C temperature rise by 2100, reports UN". The Financial Times Limited.
The two degree target is the international climate policy goal of limiting global warming to less than two degrees Celsius compared to pre-industrialization levels (1850–1900). It is an integral part of the Paris climate agreement. [1] This objective is a political determination based on scientific knowledge concerning the probable consequences of global warming, which dates from the Copenhagen Conference in 2009. [2] Physical climate risk scenarios, which often project to the end of the century, 2100, use the 2 °C target as a reference point. The time at which global mean temperature is predicted to reach +2 °C compared to the pre-industrial period (1850–1900) is termed the "crossing year". [3]
As a global target for limiting emissions, the 2 °C target has frequently been criticized for being higher than desirable, [1] [4] because two degrees of warming will have serious consequences for humans and the environment. [5] The IPCC Special Report on Global Warming of 1.5 °C (2018) included detailed analysis of the probable differences in impact of "limiting global warming to 1.5 °C compared with 2 °C", warning that a 2 °C temperature increase would worsen impacts that include extreme weather, Arctic sea ice decline, rising sea levels, coral bleaching, and ecosystem loss. [6]
The impact of climate change is not uniform: [7] for example, land regions tend to warm faster than ocean regions. [6] NASA has modeled predicted changes in six key climate variables: air temperature, precipitation, relative humidity, wind speed, and short- and longwave solar radiation, with particular attention to their impacts on heat stress and fire weather. NASA's NEX-GDDP-CMIP6 data set models impact at a fine-grained spatial scale, which can be used to identify key risk areas and develop adaptation and mitigation action plans for specific regions. Above the 2 °C threshold, dangerous and cascading effects are predicted to occur, with many areas experiencing simultaneous multiple impacts due to climate change. [7] [8]
As of 2022, the UN Environment Programme reported that countries have not met their climate goals to date. As a result the UN Framework Convention on Climate Change predicts a likely increase between 2.1 °C and 2.9 °C in temperature by 2100, exceeding the 2 °C climate target. [9] Some scientists suggest that the development of decarbonization technologies may offer a way to reverse the accumulation of CO2 in the atmosphere. Even if temperatures increase above 2 °C, it may become possible to halt or reverse increases by late in the century and bring CO2 levels back to the levels identified by the Paris climate agreement. [3] This type of scenario is referred to as an "overshoot pathway". [6] Achieving such an outcome will require multigenerational management over many decades. [3]
See also
References
- ^ a b Damian, Michel (18 May 2016). "Limiter le réchauffement de la planète à 1,5 °C ? La question qui brûle" [Limit global warming to 1.5 °C? The burning question]. The Conversation (in French). Retrieved 22 August 2018..
- ^ Report of the Conference of the Parties on its fifteenth session, held in Copenhagen from 7 to 19 December 2009 (PDF) (Report). United Nations Framework Convention on Climate Change. 30 March 2010. Retrieved 9 November 2022.
- ^ a b c Hannah, L.; Midgley, G.F. (13 November 2023). "30×30 for Climate: The History and Future of Climate Change–Integrated Conservation Strategies". Annual Review of Environment and Resources. 48 (1): 1–24. doi: 10.1146/annurev-environ-112321-114023. ISSN 1543-5938. Retrieved 27 November 2023.
- ^ Pérez, Eddy (13 August 2021). "Climat : le rapport du GIEC est bouleversant. Il est maintenant temps d'agir" [Climate: the IPCC report is shocking. Now is the time to act]. The Conversation (in French). Retrieved 22 August 2022..
- ^ Roberts, David (19 January 2018). "This graphic explains why 2 degrees of global warming will be way worse than 1.5". Vox. Retrieved 27 November 2023.
- ^ a b c IPCC (2018). Global Warming of 1.5 °C: IPCC Special Report on impacts of global warming of 1.5 °C above pre-industrial levels in context of strengthening response to climate change, sustainable development, and efforts to eradicate poverty (1 ed.). Cambridge University Press. doi: 10.1017/9781009157940.001. ISBN 978-1-009-15794-0.
- ^ a b "NASA Study Reveals Compounding Climate Risks at Two Degrees of Warming". Climate Change: Vital Signs of the Planet. August 14, 2023.
- ^ Park, Taejin; Hashimoto, Hirofumi; Wang, Weile; Thrasher, Bridget; Michaelis, Andrew R.; Lee, Tsengdar; Brosnan, Ian G.; Nemani, Ramakrishna R. (May 2023). "What Does Global Land Climate Look Like at 2 °C Warming?". Earth's Future. 11 (5). doi: 10.1029/2022EF003330. ISSN 2328-4277.
- ^ Hodgson, Camilla (October 27, 2022). "Climate graphic of the week: World on track for up to 2.6C temperature rise by 2100, reports UN". The Financial Times Limited.