Hot Drought
Alta Sierra July 2016. Jeffrey pine, as well as white fir and cedar all suffering from drought.
Griffin and Anchukaitis estimate that the period from 2012- 2014 (when their paper was written) was the worst drought in the last 1200 years. They base their calculations on the PDSI index. While they found that these three years of low precipitation were not unprecedented in the past dendrochronological record, temperature rise, caused by increasing emissions of green house gases, "could have exacerbated the 2014 drought by 36%," resulting in such dire conditions. Throughout the 21st century temperatures are predicted to continue to climb. Over 100 million trees have died in California forests since 2010. What will these forests look like by 2100?