Changes in Winter Temperature Extremes from Future Arctic Sea-Ice Loss
and Ocean Warming
Observed rapid Arctic warming and sea-ice loss are likely to continue in
the future, unless and after greenhouse gas emissions are reduced to
net-zero. Here, we examine the possible effects of future sea-ice loss
at 2°C global warming above pre-industrial levels on winter temperature
extremes across the Northern Hemisphere, using coordinated experiments
from the Polar Amplification Model Intercomparison Project. 1-in-20-year
cold extremes are simulated to become less severe at high- and
mid-latitudes in response to Arctic sea-ice loss. 1-in-20-year winter
warm extremes become warmer at northern high latitudes due to sea-ice
loss, but warm by less than cold extremes. We compare the response to
sea-ice loss to that from global SST change also at 2°C global warming.
SST change causes less severe cold extremes and more severe warm
extremes globally. Except northern high latitudes, the response to SST
change is of larger magnitude than that to Arctic sea-ice loss.