Relationship between future changes in mean climate and changes in extreme events

In this study, we investigate possible future climate change over Northern Eurasia and its impact on extreme events. Northern Eurasia is a major player in the global carbon budget because of boreal forests and peatlands. Circumpolar boreal forests alone contain more than five times the amount of carbon of temperate forests and almost double the amount of carbon of the world's tropical forests. Furthermore, severe permafrost degradation associated with climate change could result in peatlands releasing large amounts of carbon dioxide and methane. Meanwhile, changes in the frequency and magnitude of extreme events, such as extreme precipitation, heat waves or frost days are likely to have substantial impacts on Northern Eurasia ecosystems. For this reason, it is important to quantify the possible climate change over Northern Eurasia under different emissions scenarios, while accounting for the uncertainty in the climate response and changes in extreme events.

We analyze 45 simulations with the Massachusetts Institute of Technology (MIT) Integrated Global System Model (IGSM) framework, an integrated assessment model that couples an earth system model of intermediate complexity (with a 2D zonal-mean atmosphere) to a human activity model. Regional change is obtained by linking the MIT IGSM with the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). The IGSM-CAM simulations were carried for three values of climate sensitivity (low, median and high), three emissions scenarios and five different initial conditions. We analyze the relationship between future changes in mean climate and changes in extreme events for temperature and precipitation over Northern Eurasia.