Climate exposure of East Asian temperate forests suggests transboundary climate adaptation strategies are needed

The impacts of climate change traverse administrative borders, which calls for new strategies for forest ecosystem conservation and adaptive management. Despite relatively high biodiversity, the temperate forests in East Asia have lacked a comprehensive regional evaluation of potential climate change impacts. Here, we assess the level of climate change exposure of the Temperate Broadleaf and Mixed Forests Biome of East Asia by 2070. These temperate forests occupy 18 ecoregions, five countries, and 102 provinces. We categorize climate change exposure by classifying baseline (1960–1990) climate conditions for the current geographic distribution of five temperate forest types within each ecoregion and within the biome. We then measure the level of change under four future climates: a warmer or a hotter future climate and under reduced emissions (RCP4.5) or with emissions continuing unabated (RCP8.5). By 2070, using the RCP8.5 emission scenario, 24.5–65.7% of these forests enter non-analog or the most marginal 1% of baseline climate conditions. These results reveal the need for extensive transboundary governmental coordination, including forest preservation actions among 51 of 54 provinces that will retain some forest locations in climatically stable or low-risk conditions. Furthermore, among 96 provinces with forests that will be highly exposed, 90 will require transboundary climate change adaptation strategies because these forests span their borders, including the border areas of China, the Russian Federation, and North Korea. The analytical approach of this study could serve as a template for supporting transboundary institutional coordination to address climate change.