Historical land use and land cover change reduced the temperature of cold extremes more than that of hot extremes

Abstract

<p>The impact of historical land use and land cover change (LULCC) on the mean climate has been extensively studied, but its impact on temperature extremes is not well understood. This study investigates the biophysical effect of LULCC on temperature extremes using two sets of model simulations �C one with land use fixed at 1850 level and the other with historical LULCC from 1850 to 2014. We find that the historical LULCC has two asymmetric effects: (i) it decreases the temperature of coldest day (�C0.56 �� 0.23 K; mean �� std. error) more than that of the hottest day (�C0.21 �� 0.07 K) at the mid-latitudes of northern hemisphere; and (ii) it has a stronger impact in the mid-latitudes of northern hemisphere relative to the tropical region. These changes result largely from an indirect effect of LULCC via changes in clouds, circulations, and the downward longwave radiation. We stress that the indirect effects from climate feedback of LULCC should be considered when implementing reforestation policy.</p>