>>10589783>To begin to address these questions, we consider the Earth climate study of Meehlet al. (2013), who asked whether a future Maunder Minimum-type event might signifi-
cantly slow global warming. Meehl et al. (2013) used the Whole Atmosphere Community
Climate Model (WACCM) and modified the solar TSI input to include a step-function
0.25% decrease lasting 50 years. The model produced an immediate response in globally
averaged temperature to this small decrease in TSI compared to the baseline case with
no prolonged TSI decrease, reducing global temperature by several tenths of a degree
centigrade. However, following the period of decreased TSI the warming trend resumed
and caught up with the baseline case. Thus, Meehl et al. (2013) concludes that a future
Maunder Minimum-like event could slow down, but not stop the global warming trend.
>According to the climate models, snow cover should have steadily decreased for all four seasons.However, the observations show that only spring and summer demonstrated a long-term decrease.
Indeed, the trends for autumn and winter suggest a long-term increase in snow cover, although these
trends were not statistically significant.
>According to this new dataset, the recent period ofArctic sea ice retreat since the 1970s followed a period of
sea ice growth after the mid 1940s, which in turn followed
a period of sea ice retreat after the 1910s. Our reconstruc-
tions agree with previous studies that have noted a gen-
eral decrease in Arctic sea ice extent (for all four seasons)
since the start of the satellite era (1979).
