Emergent constraints for the climate system as effective parameters of bulk differential equations

• Published in: Earth system dynamics Vol. 14; no. 2; pp. 433 - 442
• Main Authors: Huntingford, Chris, Cox, Peter M, Williamson, Mark S, Clarke, Joseph J, Ritchie, Paul D. L
• Format: Journal Article
• Language: English
• Published: Gottingen Copernicus GmbH 17-04-2023; Copernicus Publications
• Subjects: Air pollution; Analysis; Atmospheric carbon dioxide; Atmospheric models; Carbon; Carbon cycle; Climate change; Climate models; Climate policy; Climate system; Differential equations; Environmental impact; Environmental policy; Estimates; Future climates; Gases; Geochemical cycle; Geochemical cycles; Global temperature changes; Greenhouse effect; Greenhouse gases; Hydrologic cycle; Hydrology; Intergovernmental Panel on Climate Change; Measurement; Parameter uncertainty; Partial differential equations; Research facilities; Trends; Uncertainty; Weather
• ISSN: 2190-4987; 2190-4979; 2190-4987
• DOI: 10.5194/esd-14-433-2023

Planning for the impacts of climate change requires accurate projections by Earth system models (ESMs). ESMs, as developed by many research centres, estimate changes to weather and climate as atmospheric greenhouse gases (GHGs) rise, and they inform the influential Intergovernmental Panel on Climate Change (IPCC) reports. ESMs are advancing the understanding of key climate system attributes. However, there remain substantial inter-ESM differences in their estimates of future meteorological change, even for a common GHG trajectory, and such differences make adaptation planning difficult. Until recently, the primary approach to reducing projection uncertainty has been to place an emphasis on simulations that best describe the contemporary climate. Yet a model that performs well for present-day atmospheric GHG levels may not necessarily be accurate for higher GHG levels and vice versa.