Rise and fall of vegetation primary production resilience to climate variability anticipated by a large ensemble of Earth System Models’ simulations

Abstract

Climate change is affecting many aspects of natural ecosystems and society. Anticipating the changes in vegetation resilience -the plants' capacity to cope with disturbances and shocks such as those related to climate variability and extremesis critical to understand and project ecosystems' responses to global change and the impacts on the related ecosystem services, to support mitigation actions, and to define proper adaptation plans.Here, we quantify vegetation gross primary production (GPP) resilience by computing the annual production resilience indicator from the state-of-the-art Earth System Model (ESM) simulations included in the newest Sixth Phase of the Coupled Model Intercomparison Project (CMIP6). Taking the present period as reference, we estimate the GPP resilience changes for different periods in the near and far future (2021-2050 and 2051-2100) under three scenarios of socioeconomical global changes, corresponding to different levels of greenhouse gases' emissions and land-use.In the 'Sustainability (Taking the Green Road)' and 'Middle of the Road' scenarios considered here (ssp126 and ssp245), the areas where vegetation shows increasing GPP resilience (mainly boreal, African and Indian monsoonal regions) are wider than the areas with decreasing resilience. The situation drastically reverses in the 'Fossil-fuel Development (Taking the Highway)' scenario (ssp585), mostly because the increase of GPP interannual variability outbalances the mean increase due to the CO2 fertilization effect in this high greenhouse gases' emission scenario. Among the larger countries, Brazil is exposed to the highest risk of experiencing years with anomalously low GPP, especially in the 'Taking the Highway' scenario.