Chapter 4: Future global climate: Scenario-based projections and near-term information
Abstract
The chapter 4 of Working Group I contribution to the IPCC Sixth Assessment Report assesses simulations of future global climate change, spanning time horizons from the near term (2021-2040), mid-term (2041-2060), and long term (2081-2100) out to the year 2300. The chapter assesses physical indicators of global climate change, such as global surface air temperature, global land precipitation, Arctic sea-ice area and global mean sea level. Furthermore, the chapter covers indices and patterns of properties and circulation not only for mean fields but also for modes of variability that have global significance. Changes are assessed relative to both the recent past (1995-2014) and the 1850-1900 approximation to the pre-industrial period. The projections assessed in the chapter are mainly based on a new range of scenarios, the Shared Socio-economic Pathways (SSPs) used in the Coupled Model Intercomparison Project Phase 6 (CMIP6) alongside new scientific literature since the release of Fifth Assessment Report. Additional lines of evidence enter the assessment, especially for change in globally averaged surface air temperature and global mean sea level, while assessment for changes in other quantities is mainly based on CMIP6 results. After section 4.2 on the methodologies used in the assessment, Section 4.3 assesses projected changes in key global climate indicators throughout the 21st century. Section 4.4. covers near-term climate change and Section 4.5 assesses mid-term and long-term climate change. Section 4.6 addresses the climate implications of climate policies including patterns of climate change expected for various global warming levels, climate goals, overshoot, and path-dependence, as well as the climate response the climate response to mitigation, Carbon Dioxide Removal, and Solar Radiation Modification. Section 4.7 assesses very long-term changes up to 2300 and climate-change commitment and the potential for irreversibility and abrupt climate change. The chapter concludes with Section 4.8 on the potential for low-probability-high-impact changes.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.U13B..04L