Abstract:The response of environmental change and human adaptation to global climate changes, as well as their role in climate, has been a subject of much debate. The motivation for the“Impact and Adaptation” task group of CAS Strategic Priority Research Program“Climate Change: Carbon Budget and Relevant Issues”, originated in understanding the climate of the Holocene Megathermal period—an epoch that many consider as “the closest analogue” to future greenhouse conditions with global temperature increasing by 1-2°C. The core issues of the project are to evaluate the effect of the past warming climate on the environmental pattern and terrestrial ecosystems in China, which provided the natural background for human adaptation. This is combined with exploring the how humans adapted to different climatic and environmental conditions, offering a potential future analogue for climate changes impact humans. During the last five years, our project revealed the current global warming has a natural warming cycle background and that global warming at different scales favors an increase in monsoonal rainfall, resulting in the expansion of forested areas, contraction of the deserts in north China, and increasing carbon storage in terrestrial ecosystems. In the study of human genesis and adaptation, our project has obtained new evidence for the origin and migration of Homo Sapiens in East Asia and demonstrated that the cultivation and domestication of crops was facilitated by past climate warming. During the Holocene Megathermal period, the spatial distribution of rice and millet agriculture expanded remarkably, and the advances of agricultural technology facilitated permanent human occupation of the Tibetan Plateau. In general, past climate cooling limited population size, and mild climates spurred the growth in prehistoric populations and advances in human cultures. We also found that the land area of coastal zones in China have increased nearly 14 200 km² in the last 70 years, which resulted from the intensified human activities. In future work, we will focus on the quantitative reconstruction of high-resolution paleoclimate changes, and investigate the mechanisms of interactions between climate, environment, and human activities.