The Role of Anthropogenic-Induced Surface Temperature Change on Regional Enhanced Warming over East Asia

Abstract:

In this study, the long-term trend and decadal variability of surface air temperature (SAT) are studied by using observation data from 1901-2009. We found that the warming trends of the semi-arid regions are higher than other lands, which have increased 2.42°C as compared to the global annual mean temperature increase of 1.13°C over land. To investigate the causes of Enhanced Semi-Arid Warming (ESAW), we used an advanced dynamic-adjusted method proposed by Wallace et al. (2012) to analyse the contribution of dynamically-induced and anthropogenic-induced SAT changes to ESAW. In the process of dynamic adjustment, the temperature has been divided into two parts, one for the dynamic forcing induced temperature, and the other for the temperature associated with the build-up of greenhouse gases and the other various radiative forcing. The results show that the anthropogenic-warming peak over semi-arid region plays the main role in the ESAW. Such anthropogenic warming peak may be related to reduction of snow cover due to black carbon (BC) emission by fuels for winter residential heating. Besides the impact of BC in snow, the agricultural mulch creation, wind farms and other types of human activities may also make attribution to local SAT changes that need to be further studied.