Snow and ice feedbacks prolong effects of nuclear winter

Abstract

Recent studies using climate models^1–6 have suggested that drastic surface cooling (the “nuclear winter”¹) caused by smoke and dust would follow a large-scale nuclear war, with possible drastic effects on the biosphere⁷. None of these studies looked at the long-term effects of time of year on the results. Moreover, although the general circulation model experiments of Covey et al.⁴ had snow/albedo feedback on land, none of the experiments considered long-term seasonal cryospheric interactions with the forcing, especially the sea ice/thermal inertia feedback⁸. Although, in the previous studies, the presumed transport of smoke and dust to the Southern Hemisphere was mentioned, no detailed investigation of its effects has been made. I investigate here the interactions of snow and sea ice with the forcing, and look at the effects over a period of several years for a variety of strengths of the forcing and latitudinal distribution of the nuclear smoke and dust, including Southern Hemisphere injection. The seasonal dependence of both the forcing and the response are also investigated. Previous results are supported and possible longer lasting effects are revealed. The considerable uncertainties that remain are discussed.