Assessment of the global coherence of different types of droughts in
model simulations under a high anthropogenic emission scenario
Abstract
This study provides a global analysis of drought metrics obtained from
several climatic, hydrologic and ecological variables in a climate
change framework using CMIP6 model data. A comprehensive analysis of the
evolution of drought severity on a global scale is carried out for the
historical experiment (1850-2014) and for future simulations under a
high emissions scenario (SSP5-8.5). This study focuses on assessing
trends in the magnitude and duration of drought events according to
different standardised indices over the world land-surface area. The
spatial and temporal agreement between the different drought indices on
a global scale was also evaluated. Overall, there is a fairly large
consensus among models and drought metrics in pointing to drought
increase in southern North America, Central America, the Amazon region,
the Mediterranean, southern Africa and southern Australia. Our results
show important spatial differences in drought projections, which are
highly dependent on the drought metric employed. While a strong
relationship between climatic indices was evident, climatic and
ecological drought metrics showed less dependency over both space and
time. Importantly, our study demonstrates uncertainties in future
projections of drought trends and their interannual variability,
stressing the importance of coherent hydrological and plant
physiological patterns when analysing CMIP6 model simulations of
droughts under a warming climate scenario.