资源环境科技发展态势分析平台

Radiation changes at the Earth’s surface alter climate, however the causes of observed surface radiation changes are not precisely quantified globally. With complete global coverage by ERA-Interim, the drivers of the surface clear sky downwelling longwave irradiance (SDLI) trends from 1984 through 2017 are quantifiable everywhere. Trends in atmospheric temperature and water vapor contributed significantly (∼90%) to clear sky SDLI trends, including trends consistent with Arctic warming and Southern Ocean cooling. CO₂ contributed ∼10% and other greenhouse gases (CH₄, N₂O, CFC-11, and CFC-12) ∼1% to the SDLI trends. These observation-based results are consistent with early CO₂-doubling climate model calculations wherein temperature and water vapor changes drove ∼90% of the SDLI change. The well-mixed greenhouse gases drive location-dependent SDLI trends that are strongest over regions with climatologically high temperatures and low water vapor amounts.