Grassland greening impacts on global land surface temperature

Xiangjin Shen; Yiwen Liu; Liyuan Wu; Rong Ma; Yanji Wang; Jiaqi Zhang; Lei Wang; Binhui Liu; Xianguo Lu; Ming Jiang

doi:10.1016/j.scitotenv.2022.155851

Grassland greening impacts on global land surface temperature

Sci Total Environ. 2022 Sep 10;838(Pt 1):155851. doi: 10.1016/j.scitotenv.2022.155851. Epub 2022 May 10.

Authors

Xiangjin Shen¹, Yiwen Liu², Liyuan Wu², Rong Ma³, Yanji Wang², Jiaqi Zhang⁴, Lei Wang⁵, Binhui Liu⁶, Xianguo Lu⁴, Ming Jiang⁴

Affiliations

¹ Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address: shenxiangjin@iga.ac.cn.
² Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China.
³ Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; College of Mapping and Geographical Sciences, Liaoning Technical University, Fuxin 123000, China.
⁴ Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
⁵ Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address: wanglei@iga.ac.cn.
⁶ College of Forestry, Northeast Forestry University, Harbin 150040, China.

PMID: 35561918
DOI: 10.1016/j.scitotenv.2022.155851

Abstract

Grassland vegetation greenness has been increasing globally during the past decades. Although the vegetation coverage change could have significant effects on climate by affecting albedo and evapotranspiration (ET), the effects of global grassland greening on climate remain unclear due to the lack of long-term field observation data. Here, we used satellite measurements of land surface temperature (LST) from high coverage grassland and adjacent low coverage grassland (divided according to the leaf area index) to quantify, for the first time, the biogeophysical effects of global grassland greening on surface temperatures. Results showed that grassland greening decreased the annual mean LST and daytime LST (LSTD), but did not significantly change nighttime LST (LSTN) globally from 2003 to 2017. Spatially, grassland greening had significant cooling effects on the annual mean LST and LSTD for latitudes south of 50°N due to the cooling effect of increased ET, whereas warming affects on the annual mean LST and LSTD in the high northern latitudes (> 50°N) because of the warming effects of decreased albedo. This study revealed that the effects of grassland greening on surface temperatures changed with latitude. During June, July, and August (JJA), the increasing grassland vegetation coverage decreased the LST between 25°S and 50°N, but increased the mean LST in high northern latitudes. By contrast, grassland greening has no significant effect on the mean LST in the temperate southern hemisphere (> 25°S) during JJA due to cooling and warming effects on LSTD and LSTN, respectively. During December, January, and February, grassland greening decreased the mean LST and LSTD for latitudes south of 25°N, but increased the mean LST and LSTN for latitudes north of 25°N. This study highlights the importance of including grassland vegetation coverage in models of regional surface temperature dynamics and future climate forecast.

Keywords: Climate change; Feedback; Grassland; Temperature; Vegetation greening.

MeSH terms

Climate
Climate Change*
Grassland*
Temperature