Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing
The approximate proportional relationship between cumulative carbon emissions and instantaneous global temperature rise (the carbon budget approximation) has proven to be a useful concept to translate policy-relevant temperature objectives into CO _2 emissions pathways. However, when non-CO _2 forci...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2019-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab08a9 |
| _version_ | 1797747989287010304 |
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| author | Felipe Feijoo Bryan K Mignone Haroon S Kheshgi Corinne Hartin Haewon McJeon Jae Edmonds |
| author_facet | Felipe Feijoo Bryan K Mignone Haroon S Kheshgi Corinne Hartin Haewon McJeon Jae Edmonds |
| author_sort | Felipe Feijoo |
| collection | DOAJ |
| description | The approximate proportional relationship between cumulative carbon emissions and instantaneous global temperature rise (the carbon budget approximation) has proven to be a useful concept to translate policy-relevant temperature objectives into CO _2 emissions pathways. However, when non-CO _2 forcing is changing along with CO _2 forcing, errors in the approximation increases. Using the GCAM model to produce an ensemble of ∼3000 scenarios, we show that linked changes in CO _2 forcing, aerosol forcing, and non-CO _2 greenhouse gas (GHG) forcing lead to an increase in total non-CO _2 forcing over the 21st century across mitigation scenarios. This increase causes the relationship between instantaneous temperature and cumulative CO _2 emissions to become more complex than the proportional approximation often assumed, particularly for low temperature objectives such as 1.5 °C. The same linked changes in emissions also contribute to a near-term increase in aerosol forcing that effectively places a limit on how low peak temperature could be constrained through GHG mitigation alone. In particular, we find that 23% of scenarios that include CCS (but only 1% of scenarios that do not include CCS) achieve a temperature objective of 1.5 °C without temperature overshoot. |
| first_indexed | 2024-03-12T15:59:30Z |
| format | Article |
| id | doaj.art-5120e01eb49740e29adfa1d2f3fb39bf |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:59:30Z |
| publishDate | 2019-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5120e01eb49740e29adfa1d2f3fb39bf2023-08-09T14:43:01ZengIOP PublishingEnvironmental Research Letters1748-93262019-01-0114404400710.1088/1748-9326/ab08a9Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcingFelipe Feijoo0https://orcid.org/0000-0003-3129-9597Bryan K Mignone1Haroon S Kheshgi2Corinne Hartin3Haewon McJeon4Jae Edmonds5School of Industrial Engineering, Pontificia Universidad Católica de Valparaíso , Valparaíso, Chile; Pacific Northwest National Laboratory—Joint Global Change Research Institute , College Park, MD, 20740, United States of AmericaExxonMobil Research and Engineering Company, Annandale, NJ, 08801, United States of AmericaExxonMobil Research and Engineering Company, Annandale, NJ, 08801, United States of AmericaPacific Northwest National Laboratory—Joint Global Change Research Institute , College Park, MD, 20740, United States of AmericaPacific Northwest National Laboratory—Joint Global Change Research Institute , College Park, MD, 20740, United States of AmericaPacific Northwest National Laboratory—Joint Global Change Research Institute , College Park, MD, 20740, United States of AmericaThe approximate proportional relationship between cumulative carbon emissions and instantaneous global temperature rise (the carbon budget approximation) has proven to be a useful concept to translate policy-relevant temperature objectives into CO _2 emissions pathways. However, when non-CO _2 forcing is changing along with CO _2 forcing, errors in the approximation increases. Using the GCAM model to produce an ensemble of ∼3000 scenarios, we show that linked changes in CO _2 forcing, aerosol forcing, and non-CO _2 greenhouse gas (GHG) forcing lead to an increase in total non-CO _2 forcing over the 21st century across mitigation scenarios. This increase causes the relationship between instantaneous temperature and cumulative CO _2 emissions to become more complex than the proportional approximation often assumed, particularly for low temperature objectives such as 1.5 °C. The same linked changes in emissions also contribute to a near-term increase in aerosol forcing that effectively places a limit on how low peak temperature could be constrained through GHG mitigation alone. In particular, we find that 23% of scenarios that include CCS (but only 1% of scenarios that do not include CCS) achieve a temperature objective of 1.5 °C without temperature overshoot.https://doi.org/10.1088/1748-9326/ab08a9carbon budgetnon-CO2cumulative carbon emissionsglobal temperatureradiative forcing |
| spellingShingle | Felipe Feijoo Bryan K Mignone Haroon S Kheshgi Corinne Hartin Haewon McJeon Jae Edmonds Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing Environmental Research Letters carbon budget non-CO2 cumulative carbon emissions global temperature radiative forcing |
| title | Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing |
| title_full | Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing |
| title_fullStr | Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing |
| title_full_unstemmed | Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing |
| title_short | Climate and carbon budget implications of linked future changes in CO2 and non-CO2 forcing |
| title_sort | climate and carbon budget implications of linked future changes in co2 and non co2 forcing |
| topic | carbon budget non-CO2 cumulative carbon emissions global temperature radiative forcing |
| url | https://doi.org/10.1088/1748-9326/ab08a9 |
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