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.