Fig. 4. Observed change in outdoor days. Normalized change in outdoor days in 1991–2020 with respect to 1961-1990. The changes are normalized by the 1961-1990 mean. These global maps are derived from ERA5.
Based on the General Circulation Model (GCM) projections from the CMIP5 and CMIP6 archives, the observed warming trend is projected to continue towards the end of the 21st century (Fig. 5 and Fig. S2). For the period 2071-2100, most land areas in the globe will likely experience significant warming by an average of 5.0 ℃ from CMIP5 models and by an average of 5.4 ℃ from CMIP6 models under high-emissions scenarios, though with some spatial variability. The overall warming across the global land surface shows no evidence for a north-south disparity, except for the projection that high latitudes may warm more significantly. The consistency between the CMIP5 and CMIP6 models is robust, ensuring the reliability of future projections.