Abstract
The increased availability of daily model output in the latest
generation of climate models should allow us a greater understanding of,
and an improved ability to predict, future trends in short duration
extreme temperature events. We examine the changes in 1, 3, and 5 day
averaged annual maximum temperature at the levels of global warming
highlighted by the 2016 Paris Agreement, and an additional degree of
warming. These events are characterised using daily near surface air
temperature output from four large ensemble models in the SSP370
scenario of the Coupled Model Intercomparison Project Phase Six (CMIP6).
Bootstrapped distributions of ensemble members are fitted to the
generalised extreme value distribution and the changes in location,
scale and shape parameters examined at the respective warming levels,
compared to the last 10 years of historical model runs. Global trends in
location parameter indicate increased warming over land relative to
oceans while shape and scale parameters show less globally consistent
trends but very clear signals of strong changes over the Arctic sea ice.
Risk ratios are determined for extreme temperature events with a return
value of 10 years in the historical period, compared to future levels of
warming, using the calculated GEV distributions. Risk Ratios increase
globally with mean temperature change, with greater increases over the
tropics, particularly over the oceans. Longer events are also found to
have a greater increase in occurrence than shorter duration temperature
extremes.