The What If Modeling Intercomparison Project (WhatIfMIP) is a Community MIP developed for CMIP7 in coordination with the WCRP Safe Landing Lighthouse Activity. It aims to understand the global consequences and cascading regional impacts after the future tipping of certain Earth system components.
It is being coordinated with other proposed tipping point explorations (TIPMIP, TipESM) that consider spontaneous tipping, while WhatIfMIP (and ClimTIP) imposes tipping to have occurred.
Experiments are being designed that assume that this tipping element will have already occurred (‘It’s happened’). These experiments are intended to be doable by any AOGCM. It will allow the CMIP AR7 modeling centers to run these experiments even if they do not have certain Earth system components as interactive in their models, or if mechanisms of tipping do not show the correct sensitivity or interaction mechanisms. It fills in experiments not covered elsewhere but considered important for complete, country-specific risk assessment.
Initial experiments for this multi-model intercomparison project are being developed for future scenarios of:
- Boreal Forest – Northern Expansion and Southern Dieback
- Sahel Greening
- Amazon Rainforest Browning
- Greenland Ice Sheet Collapse
- West Antarctic Ice Sheet Collapse
- Boreal Permafrost Collapse
Designs and participation for additional experiments are welcome.
WhatIfMIP experiments will be based on the Global Warming Level (GWL) simulations of 2°C and 4°C following the protocols being used by the Tipping Point Consortium. Protocols are flexible to allow models that are capable for emission-driven simulations or concentration-driven simulations.