Periodic Reporting for period 1 - FORCeS (Constrained aerosol forcing for improved climate projections)
Reporting period: 2019-10-01 to 2021-03-31
i. New fundamental understanding of physical and chemical processes involving aerosols and clouds;
ii. Climate models with new and improved description of aerosols and aerosol-cloud interactions;
iii. Improved predictions of climate evolution in the context of climate policy, particularly the PA;
iv. Improved quantification and reduction of uncertainty related to aerosol radiative forcing, climate sensitivity and transient climate response.
FORCeS has already made substantial progress towards these outcomes. Two field campaigns in Arctic and sub-Arctic environments were successfully executed, despite the covid-19 pandemic. These observations provide unique and novel insights into aerosol-cloud interaction processes. Laboratory experiments have generated additional knowledge on detailed aerosol processes. The ongoing evaluation of experimental results will form a basis for improving the ESMs. A future campaign will also provide information on aerosol and fog properties in a highly polluted region of Europe.
FORCeS participants have contributed with model simulations relevant for the sixth Assessment Report (AR6) of the IPCC, expected to be published in 2021. A collaborative effort between modelling and experimental groups has generated concrete steps towards implementation of the process-knowledge into FORCeS ESMs. We have benchmarked the current versions of FORCeS ESMs to prepare for the evaluation of new process descriptions. New and existing datasets suitable for model evaluation have been compiled, which will be crucial for constraining FORCeS ESMs to produce reduced uncertainty related to aerosol radiative forcing. FORCeS has also evaluated the ESMs against new types of metrics, referred to as “emergent constraints” in the climate community. This evaluation will guide future model improvements and help identify promising avenues for new constraints. In the next period, FORCeS will develop constraints over the multitude of scales that govern aerosol-cloud-climate interactions.
The objectives of FORCeS are specifically designed to meet the following impacts:
i. Supporting major international scientific assessments;
ii. Increase confidence in climate projections;
iii. Providing added value to decision- and policymakers;
iv. Sustaining Europe’s leadership in climate science.
FORCeS has made substantial progress towards these impacts. FORCeS results will be included in the upcoming IPCC AR6, and project participants have been highly involved in writing this report. FORCeS members have also contributed to the upcoming 2021 assessment report by the Arctic Monitoring and Assessment Program (AMAP). A first landmark paper is under production, which outlines the major components and reasons for the large persistent uncertainty in aerosol radiative forcing. Simultaneously, FORCeS has taken steps towards mitigating some of these issues, for example by enhancing the dialogue between different aerosol-cloud-climate research communities. These efforts will, together with the above work, lead to the desired increased confidence in climate projections. After a dialogue with stakeholders, FORCeS released its first policy brief aimed at providing decision- and policymakers with information on the potential conflicts between the clean air goals of the European Green Deal and climate neutrality. By engaging in a “Science2Policy” event, FORCeS has contributed to a collection of key policy messages and research needs in climate science. From a wider perspective, FORCeS provides essential information for developing cost effective multi-beneficial abatement strategies, providing better health and resilient food production, supporting several of the United Nations’ Sustainable Development Goals. The novel and innovative methods applied in FORCeS will improve three leading European ESMs and help ensuring Europe’s leading position in climate science.