Highest rates of regional climate warming over the last decades and assessment of the role of natural and anthropogenic factors

Abstract

Based on model results and a comparison with observation and reanalysis we examined the ability of the global climatic model to reproduce temperature variations in regions with the greatest trend of warming near the surface over the last decades (Siberia and Alaska in the Northern Hemisphere; the Antarctic Peninsula in the Southern Hemisphere [1, 2]) with an assessment of the role of natural and anthropogenic factors. According to observations, the rate of global warming near the surface has been increasing over the last decades [3] (see also [2]). During the last three decades of the 20th century, the global annual mean surface air temperature increased at a rate of approximately 0.2 K/10 yr [5]. The maximum values of regional trends in surface air temperatures for the last decades are several times higher than for the Earth as a whole. In particular, a temperature trend of 0.4 K/10 yr was recorded for Siberia in the second half of the 20th century [6]. The most intense warming for Russia was recorded in winters (0.5 K/10 yr) and springs (0.3 K/10 yr). The comparison between observations and the results of numerical simulations using climatic of the general circulation models (CGCM) in the atmosphere and oceans indicates that both natural and anthropogenic factors contributed much to global changes in the surface air temperature in the 20th century [3, 5, 7‐9]. According to model simulations, global warming during the last decades of the past century cannot be accounted for solely by natural causes and without consideration of the anthropogenic factor [3, 5, 9].