Projected Increases in the Number of Days over 90 Degrees

The data used to cre­ate this fig­ure comes from Fig­ure 16.2 in the Third Nation­al Cli­mate Assess­ment report. It shows the aver­age of pro­jec­tions of the num­ber of days over 90 degrees Fahren­heit in the north­east from sev­er­al cli­mate mod­els. On the glob­al scale, cli­mate mod­el sim­u­la­tions show con­sis­tent pro­jec­tions of future tem­per­a­ture con­di­tions under a range of emis­sions sce­nar­ios. All mod­els show warm­ing by late this cen­tu­ry that is much larg­er than his­tor­i­cal vari­a­tions near­ly every­where glob­al­ly. For the U.S., mod­els unequiv­o­cal­ly project large and his­tor­i­cal­ly unprece­dent­ed future warm­ing in every region of the U.S. under all of the sce­nar­ios used in this assess­ment. The amount of warm­ing varies sub­stan­tial­ly between high­er ver­sus low­er sce­nar­ios, and mod­er- ate­ly from mod­el to mod­el, but the amount of pro­ject­ed warm­ing is much larg­er than his­tor­i­cal vari­a­tions. Like­wise, the mod­els project unequiv­o­cal increas­es in the num­ber of days over 90 degrees Fahren­heit that are larg­er than his­tor­i­cal vari­a­tions.

Cita­tion: Melil­lo, Jer­ry M., Terese (T.C.) Rich­mond, and Gary W. Yohe, Eds., 2014: Cli­mate Change Impacts in the Unit­ed States: The Third Nation­al Cli­mate Assess­ment. U.S. Glob­al Change Research Pro­gram, 841 pp. doi:10.7930/J0Z31WJ2