A 2015 study says that if global greenhouse gas emissions are reduced significantly, parts of Southern California (such as Los Angeles and Riverside) can avoid over a month of additional extremely hot (95-degree) days by the end of the century.
Los Angeles, which currently averages 6 extremely hot days per year, will face either 54 (if global emissions continue) or 15 extremely hot days (if global emissions are cut) by 2100.
A 2015 NASA study finds that unabated global greenhouse gas emissions will increase the risk of a 30-year long "megadrought" in the Southwestern U.S.
Megadrought likelihood is on pace to increase from the current 12% to 80% by 2100.
Reducing global emissions can lower this risk to 60% or less.