The Response of Radiative Forcing to High Spatiotemporally Resolved Land‐Use Change and Transition From 1982 to 2010 in China

Significant uncertainties remain in the estimate of radiative forcing (RF) induced by land‐use change (LUC), partially attributable to the lack of reliable LUC data with a high spatiotemporal resolution. We implemented a high spatiotemporally resolved LUC data set in an earth system model (OSCAR) to examine the response of RF to LUC from 1982 to 2010 in China. Results were compared with the RF estimated using a low spatiotemporally resolved LUC inventory employed previously. The updated LUC data set reduces negative RF by −3.8% from 2000 to 2010 due to the changes in surface albedo subject to LU transition. The simulated mean RF driven by CO2associated with LUC from 1982 to 2010 using a high spatiotemporally resolved LUC data set reached 0.074 W m−2, considerably higher than 0.022 W m−2of mean RF derived from the low spatiotemporally resolved LUC inventory, implying increasing net RF and more substantial LUC induced warming. Land‐use change (LUC) is considered the second anthropogenic source of climate change after fossil fuel combustion. However, significant uncertainties remain in the estimate of radiative forcing (RF) induced by LUC, partially attributable to the lack of reliable LUC data with a high spatiotemporal resolution. This study incorporated a new LUC data set with a high spatiotemporal resolution into a compact earth‐system model OSCAR to quantify the response of RF to LUCs from 1982 to 2010 in China. We assessed changes in RF for this period subject to the altered surface albedo and carbon emission associated with human‐disturbed land‐use transitions. We compared estimated RF values with those obtained using previously adopted LUC data with a low spatiotemporal resolution, which failed to identify detailed LUCs occurring in China for the past four decades. We show that the updated LUC data set weakens the cooling effect featured by negative RF‐induced by surface albedo variation but significantly enhances positive RF due to CO2emissions from LU transition. We identify that the LU transition between grassland and cropland and between cropland and forest made the most significant contribution to the changes in RF, attributable to China's national strategies for urbanization, conservation of agricultural resources, and forest expansion. A high spatiotemporally‐resolved land‐use change (LUC) data set was used to reduce uncertainties in the estimation of radiative forcing (RF)Modeled RF using the new LUC data set suggests that cooling effect was overestimated by LUC‐induced‐albedo on a low spatiotemporal resolutionThe new LUC data yields considerably higher RF induced by LU transition and CO2emissions in the past decades in China A high spatiotemporally‐resolved land‐use change (LUC) data set was used to reduce uncertainties in the estimation of radiative forcing (RF) Modeled RF using the new LUC data set suggests that cooling effect was overestimated by LUC‐induced‐albedo on a low spatiotemporal resolution The new LUC data yields considerably higher RF induced by LU transition and CO2emissions in the past decades in China