Transient climate response

Short description: How much global warming depends on atmospheric carbon dioxide

The transient climate response to cumulative emissions of carbon dioxide (TCRE) is the ratio of the globally averaged surface temperature change per unit carbon dioxide (CO2) emitted.[1][2]

[3]

[4] As emitted CO2 may stay in the atmosphere for thousands of years, this response is the amount that the global temperature changes per the net amount of total carbon dioxide emitted by human activities into the atmosphere.[5][6][2] Scientists agree that global temperature changes linearly regardless of the path taken to reach peak cumulative CO2 emissions.[7][8][2] This means that for specific amount of cumulative CO2 emissions, a known global temperature change (within a range of uncertainty) can be expected, which indicates that holding global temperature change to below specific thresholds is a problem of limiting cumulative CO2 emissions, leading to the idea of a carbon budget.[2][9][3]

## Contents

* 1 Calculation
* 1.1 Formulas
* 1.2 Modeling
* 2 Temperature Response
* 2.1 Global response
* 2.2 Regional response
* 2.2.1 Regional precipitation response
* 3 Carbon budget
* 4 See also
* 5 References

## Calculation

### Formulas

The TCRE can be calculated based on a formula for the ratio of temperature change to cumulative carbon emissions (measured as CO2), which is the net carbon remaining in the atmosphere after accounting for relevant sources and sinks.[6] As a measure of atmospheric carbon change, the TCRE parameterizes how sensitive the climate is to carbon dioxide to formulate a value that is the temperature change (°C) per trillion tonnes of carbon emitted (Tt C).[6][5] This is represented via the following formula:

TCRE=△T/ET=(△T/△CA)×(△CA/ET)[6]

where,

* ΔT = average global temperature change (°C)
* ET = cumulative carbon dioxide emissions (Tt C)
* ΔCA = change in atmospheric carbon (Tt C)

and, 1Tt C = 3.8 Tt CO2

TCRE can also be defined not in terms of temperature response to emitted carbon, but in terms of temperature response to the change in radiative forcing:[10]

TCRE=△T/RF[10]

where,

* RF = radiative forcing (W/m2) taken at the top of the atmosphere (TOA)

Here TCRE is used to assess the assumed linear effect radiative forcing has on temperature change in an historical analysis.[10]

### Modeling

TCRE is modeled using climate models that simulate carbon emissions by increasing CO2 emissions by 1% per year from pre-industrial levels until the concentration of CO2 in the atmosphere is doubled (2 x CO2) or quadrupled (4 x CO2).[11][6][2][9] Since these experiments all start from the same initial atmospheric concentration of CO2 (around 285 ppm[12]), the doubling and quadrupling occur at 70 and 140 years respectively. Different modelling parameterizations of TCRE include: holding CO2 emissions constant after quadrupling;[12] modelling net negative emissions after doubling or quadrupling;[7] stopping emissions after doubling and continuing the model for up to 10,000 years;[13] or running extended RCP scenarios and assessing temperature change per cumulative emissions at high CO2 concentrations.[8]

## Temperature Response

### Global response

Global temperature change is approximately linearly proportional to cumulative carbon emissions.[9][2] This means that for a given amount of carbon emissions, a related amount of global warming can reasonably be expected.[6][14] The IPCC Sixth Assessment Report, which is the most thorough estimate as of 2021,[3] suggests a likely TCRE of 1.4 °C–2.2 °C per Tt C (or 1000 Pg C), a narrowing of the 0.8° to 2.5 °C per Tt C range estimated by the IPCC in 2013.[9]

### Regional response

Though the global average temperature response to cumulative emissions is approximately linear, this response is not uniform throughout the globe.[2][1][15] Calculations by Leduc et al., (2016) of the geographical pattern of temperature response (the regional TCRE, or RTCRE) show values of low temperature change over equatorial and tropical ocean regions and high values of temperature change exceeding 4 °C/Tt C in the Arctic.[1] Likewise, they show a pronounced temperature response difference between the land and ocean, which is largely because the ocean absorbs much of the heat.[1][12][16]

#### Regional precipitation response

Unlike the positive regional temperature response, regional precipitation change to cumulative emissions are positive or negative, depending on location.[15] Partanen et al., (2017) show a strong positive precipitation response in the Arctic with negative responses (meaning reduced precipitation) in parts of Southern Africa, Australia, North and South America.[15]

## Carbon budget

Main article: Earth:Carbon budget

The observed and calculated linear TCRE leads to the notion of a carbon budget.[9][3][17] A carbon budget is "the maximum amount of cumulative net global anthropogenic carbon dioxide (CO2) emissions that would result in limiting global warming to a given level with a given probability, taking into account the effect of other anthropogenic climate forcers".[4]

## See also

* Climate sensitivity
* Global warming

## References

1. ↑ 1.0 1.1 1.2 1.3 Leduc, M.; Matthews, H.D.; de Elia, R. (January 4, 2016). "Regional estimates of the transient climate response to cumulative CO2 emissions". Nature Climate Change 6 (5): 474–478. doi:10.1038/NCLIMATE2913.
2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Matthews, H.D.; Zickfeld, K.; Knutti, R.; Allen, M.R. (January 12, 2018). "Focus on cumulative emissions, global carbon budgets and the implications for climate mitigation targets". Environmental Research Letters 13: 010201. doi:10.1088/1748-9326/aa98c9.
3. ↑ 3.0 3.1 3.2 3.3 "Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change". Global Carbon and other Biogeochemical Cycles and Feedbacks. Cambridge University Press. 2021. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter05.pdf.
4. ↑ 4.0 4.1 "Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change". Annex VII: Glossary. Cambridge University Press. 2021. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Annex_VII.pdf.
5. ↑ 5.0 5.1 Allen, M.R.; Frame, D.J.; Huntingford, C.; Lowe, J.A.; Meinshausen, M.; Meinshausen, N. (April 30, 2009). "Warming caused by cumulative emissions towards the trillionth tonne". Nature 458 (7242): 1163–1166. doi:10.1038/nature08019. PMID 19407800.
6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Matthews, H.D.; Gillett, N.P.; Stott, P.A; Zickfeld, K (June 11, 2009). "The proportionality of global warming to cumulative carbon emissions". Nature 459 (7248): 829–832. doi:10.1038/nature08047. PMID 19516338.
7. ↑ 7.0 7.1 Zickfeld, K.; MacDougall, A.H.; Matthews, H.D. (May 12, 2016). "On the proportionality between global temperature change and cumulative CO2 emissions during periods of net negative CO2 emissions". Environmental Research Letters 11 (5). doi:10.1088/1748-9326/11/5/055006.
8. ↑ 8.0 8.1 Tokarska, K.B.; Gillett, N.P.; Weaver, A.J.; Arora, V.K.; Eby, M. (May 23, 2016). "The climate response to five trillion tonnes of carbon". Nature Climate Change 6 (9): 851–855. doi:10.1038/NCLIMATE3036.
9. ↑ 9.0 9.1 9.2 9.3 9.4 Collins, M.; Knutti, R.; Arblaster, J.; Dufresne, J.-L.; Fichefet, T.; Friedlingstein, P.; Gao, X.; Gutowski, W.J. et al. (2013). Stocker, T.F.; Qin, D.; Plattner, G.-K. et al.. eds. "Long-term climate change: Projections, commitments and irreversibility". In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA).
10. ↑ 10.0 10.1 10.2 Myhre, Gunnar; Boucher, Olivier; Bréon, François-Marie; Forster, Piers; Shindell, Drew (March 2015). "Declining uncertainty in transient climate response as CO2 forcing dominates future climate change". Nature Geoscience 8 (3): 181–185. doi:10.1038/ngeo2371. ISSN 1752-0908. http://eprints.whiterose.ac.uk/85097/1/14970_3_merged_1421254578.pdf.
11. ↑ Williams, Richard G.; Goodwin, Philip; Roussenov, Vassil M.; Bopp, Laurent (2016). "A framework to understand the transient climate response to emissions". Environmental Research Letters 11 (1). doi:10.1088/1748-9326/11/1/015003. ISSN 1748-9326.
12. ↑ 12.0 12.1 12.2 Gillett, Nathan P.; Arora, Vivek K.; Matthews, Damon; Allen, Myles R. (2013-09-09). "Constraining the Ratio of Global Warming to Cumulative CO2Emissions Using CMIP5 Simulations*". Journal of Climate 26 (18): 6844–6858. doi:10.1175/jcli-d-12-00476.1.
13. ↑ Frölicher, Thomas L.; Paynter, David J. (2015). "Extending the relationship between global warming and cumulative carbon emissions to multi-millennial timescales". Environmental Research Letters 10 (7). doi:10.1088/1748-9326/10/7/075002. ISSN 1748-9326.
14. ↑ Frame, David J.; Macey, Adrian H.; Allen, Myles R. (2014-09-21). "Cumulative emissions and climate policy". Nature Geoscience 7 (10): 692–693. doi:10.1038/ngeo2254.
15. ↑ 15.0 15.1 15.2 Partanen, Antti-Ilari; Leduc, Martin; Matthews, H. Damon (2017). "Seasonal climate change patterns due to cumulative CO 2 emissions". Environmental Research Letters 12 (7): 075002. doi:10.1088/1748-9326/aa6eb0. ISSN 1748-9326.
16. ↑ Bryan, K.; Komro, F.G.; Manabe, S.; Spelman, M.J. (January 1, 1982). "Transient climate response to increasing atmospheric carbon dioxide". Science 215 (4528): 56–58. doi:10.1126/science.215.4528.56. PMID 17790468.
17. ↑ Rogelj, Joeri; Forster, Piers M.; Kriegler, Elmar; Smith, Christopher J.; Séférian, Roland (2019-07-18). "Estimating and tracking the remaining carbon budget for stringent climate targets" (in en). Nature 571 (7765): 335–342. doi:10.1038/s41586-019-1368-z. ISSN 0028-0836. PMID 31316194.

* v
* t
* e

Global warming

Temperatures

* Geologic record
* Hiatus
* Historical climatology
* Instrumental record
* Proxy data
* Record of the past 1,000 years

Causes

| Human

* Attribution of recent climate change
* Aviation
* Black carbon
* Carbon dioxide
* Deforestation
* Fossil fuel
* Global dimming
* Greenhouse effect
* Infrared window
* Greenhouse gases
* Land use, land-use change, and forestry
* Tropospheric ozone

|

Natural|

* Bond events
* Climate variability
* AMO
* ENSO
* IOD
* PDO
* Global cooling
* Milankovitch cycles
* Orbital forcing
* Solar variation
* Volcanism

History

* History of climate change science
* Atmospheric thermodynamics
* Svante Arrhenius
* James Hansen
* Charles David Keeling

Effects and issues

| Physical|

* Abrupt climate change
* Anoxic event
* Arctic methane emissions
* Drought
* Ocean acidification
* Ozone depletion
* Physical impacts
* Retreat of glaciers since 1850
* Runaway climate change
* Sea level rise
* Season creep
* Shutdown of thermohaline circulation

|

Flora and fauna|

* Climate change and ecosystems
* Effects on plant biodiversity
* Effects on marine mammals
* Extinction risk from global warming
* Forest dieback

Society|

* Climate change and agriculture
* Climate change and ecosystems
* Climate change and gender
* Climate change and poverty
* Economics of global warming
* Effects on health
* Effects on humans
* Environmental migrant
* Fisheries and climate change
* Industry and society

By country|

* Australia
* South Asia
* India
* Nepal

Society and climate change

| General|

* Environmental ethics
* Climate movement
* Media coverage of global warming
* Public opinion on global warming
* Popular culture
* Scientific consensus on climate change
* Scientists who disagree with the mainstream assessment
* Climate change denial

|

By country & region|

* Africa
* Arctic
* Argentina
* Australia
* Bangladesh
* Belgium
* Canada
* China
* Europe
* European Union
* Finland
* Grenada
* India
* Japan
* Luxembourg
* New Zealand
* Norway
* Russia
* Scotland
* South Korea
* Sweden
* Tuvalu
* Turkey
* United Kingdom
* United States

Politics

| General|

* Climate change denial
* Intergovernmental Panel on Climate Change (IPCC)
* United Nations Framework Convention on Climate Change (UNFCCC / FCCC)
* Global climate regime

|

International|

* Kyoto Protocol
* Clean Development Mechanism
* Joint Implementation
* Bali Road Map
* Copenhagen Summit
* Paris Agreement
* United States withdrawal

Regional policy|

* Clean Power Plan
* California Climate Credit
* European Climate Change Programme
* G8 Climate Change Roundtable
* United Kingdom Climate Change Programme
* Regional climate change initiatives in the United States
* List of climate change initiatives

Protest|

* Extinction Rebellion
* Global Climate March
* List of environmental protests
* School strike for climate

Mitigation

| Emissions reduction|

* Carbon credit
* Carbon-neutral fuel
* Carbon offset
* Carbon tax
* Emissions trading
* Fossil fuel phase-out

|

Carbon-free energy|

* Efficient energy use
* Renewable energy
* Low-carbon economy
* Nuclear power
* Carbon capture and storage
* Energy transition

Personal|

* Individual action on climate change
* Simple living

Other|

* Carbon dioxide removal
* Climate change mitigation scenarios
* Climate engineering
* Reducing emissions from deforestation and forest degradation
* Reforestation
* Urban reforestation

Climate change adaptation

| Strategies|

* Desalination
* Drought tolerance
* Sustainable development
* Weather modification

|

Programmes|

* Land allocation decision support system

Background and theory

| Measurements|

* Satellite measurements

|

Theory|

* Albedo
* Carbon sink
* Climate change (general concept)
* Climate sensitivity
* Cloud forcing
* Feedbacks
* Effective temperature
* Earth's energy budget
* Global warming potential
* Radiative forcing

Research|

* Paleoclimatology
* Paleotempestology
* Climate model

* Glossary
* Index
* Climate change
* Global warming
* Portal

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Transient climate response. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Earth:Transient_climate_response&oldid=3997228"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template