Anthropogenic climate change is unfolding rapidly, yet its regional manifestation is often obscured by naturally occurring variability internal to the atmosphere and ocean system. A primary goal of climate science is to distinguish the forced response, i.e., the spatiotemporal evolution of climate in response to external forcing such as greenhouse gases, anthropogenic aerosols, volcanoes, land-use change, and solar variability, from the noise of internal climate variability. Disentangling the forced and internal components of climate change is critical for attributing historical climate changes, for characterizing and understanding internal climate variability, and for improving observationally constrained projections of future climate. This is especially true for regional climate, in which internal variability can be comparable to or larger in magnitude than the forced response.
Separating the forced response from internal variability can be addressed in climate models by taking the average over a large ensemble, where the same model is run multiple times with small differences in initial conditions leading to different realizations of internal variability. However, there is only one realization of the real world, which makes it a major challenge to isolate the forced response in observations. Nevertheless, it is critical to isolate the forced response in observations, because estimates of the forced response from climate models vary widely and are subject to biases.
The Forced Component Estimation Statistical Method Intercomparison Project (ForceSMIP) utilizes climate model ensembles to develop and assess statistical methods for isolating the forced response from individual realizations of the climate system. These methods are then applied to observations to produce a community estimate of the forced climate response. The results of this project will in turn inform climate model evaluation, attribution of recent regional climate trends, and regional planning for near-term climate change.
ForceSMIP is open to participants from around the world, as detailed in the How to Participate tab. The deadlined are now passed for the first phase of ForceSMIP, encompassing three tiers focused on different time periods. However, there are still opportunities to get involved, e.g., by collaborating with us to demonstrate the findings and applications of the exciting ForceSMIP dataset that has been produced. Additionally, there are tentative plans for a ForceSMIP Phase II, focused on seperating the greenhouse-gas and anthropogenic-aerosol components of forced changes. Please get in contact if you are interested in getting involved.
We held hackathons on August 29-31, 2023 in two locations, ETH Zürich in Zurich, Switzerland and the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. See the Hackathon tab for more information.
For publications and other output from the project, see the Outcomes tab.
ForceSMIP is organized by
Robert Jnglin Wills (primary contact) r.jnglinwills@usys.ethz.ch
Clara Deser cdeser@ucar.edu
Karen McKinnon kmckinnon@ucla.edu
Adam Phillips asphilli@ucar.edu
Stephen Po-Chedley pochedley1@llnl.gov
Sebastian Sippel sebastian.sippel@uni-leipzig.de