title: Afforestation in China cools local land surface temperature.
abstract: China has the largest afforested area in the world (∼62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects.
authors: Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors: Shu-Shi
authors: SS
authors: Peng
authors: Shilong
authors: S
authors: Piao
authors: Zhenzhong
authors: Z
authors: Zeng
authors: Philippe
authors: P
authors: Ciais
authors: Liming
authors: L
authors: Zhou
authors: Laurent Z X
authors: LZ
authors: Li
authors: Ranga B
authors: RB
authors: Myneni
authors: Yi
authors: Y
authors: Yin
authors: Hui
authors: H
authors: Zeng
mesh_terms: D002681:China; D057231:Climate Change; D003198:Computer Simulation; D017753:Ecosystem; D062305:Geographic Mapping; D005843:Geography; D008962:Models, Theoretical; D018526:Plant Transpiration / Q000502:physiology; D013696:Temperature; D014197:Trees / Q000254:growth & development*
keywords: climate change mitigation; plantation effects; surface cooling; vegetation feedback