Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544.
School of Hydrology and Water Resources Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Proc Natl Acad Sci U S A. 2021 Aug 17;118(33). doi: 10.1073/pnas.2026241118.
Because of the large carbon sequestration potential, reforestation and afforestation (R&A) are among the most prominent natural climate solutions. However, while their effectiveness is well established for wet tropics, it is often argued that R&A are less advantageous or even detrimental at higher latitudes, where the reduction of forest albedo (the amount of reflected solar radiation by a surface) tends to nullify or even overcome the carbon benefits. Here, we carefully analyze the situation for R&A at midlatitudes, where the warming effects due to vegetation albedo are regarded to be almost balanced by the cooling effects from an increased carbon storage. Using both satellite data and atmospheric boundary-layer models, we show that by including cloud-albedo effects due to land-atmosphere interactions, the R&A cooling at midlatitudes becomes prevalent. This points to a much greater potential of R&A for wet temperate regions than previously considered.
由于具有巨大的碳固存潜力，再造林和植树造林（R&A）是最突出的自然气候解决方案之一。然而，尽管它们在湿润热带地区的有效性已得到充分证实，但人们常常认为，在高纬度地区，R&A 的益处较小，甚至有害，因为森林反照率（表面反射的太阳辐射量）的降低往往会抵消甚至超过碳的益处。在这里，我们仔细分析了中纬度地区的 R&A 情况，由于植被反照率引起的变暖效应几乎被增加的碳储存带来的冷却效应所平衡。我们使用卫星数据和大气边界层模型表明，通过包括由于陆地-大气相互作用而产生的云反照率效应，中纬度地区的 R&A 冷却作用变得普遍。这表明，与之前认为的相比，湿润温带地区的 R&A 潜力要大得多。
