CAREER: Experimental Warming, Permafrost Thawing, and the Loss of Old Carbon from Tundra: Radiocarbon Research and Education to Understand Ecosystem Feedbacks to Climate Change

北部生态系统的土壤和永久冻土中含有足够的碳，使大气中目前的二氧化碳增加一倍。由于永久冻土碳库的大小和性质，对以前冻结的旧有机碳的分解是陆地生态系统对气候变化最有可能的积极反馈之一。该项目使用放射性碳测量作为检测旧土壤碳损失的唯一指纹，并结合生态系统规模的田间操作来确定对永久冻土碳释放的控制。这项高精度的同位素研究与继续开发和教授一门密集的短期课程相结合，旨在让学生接触到用于测量放射性碳的新兴加速器质谱学技术。越来越多的放射性碳测量，加上更多的研究人员熟练地解释这些数据，为探测生态系统和全球碳循环的变化提供了巨大的希望。气候变化正在改变我们生活的世界。目前，导致气候变化的温室气体增加在很大程度上是人类活动的结果。然而，气候变化可能会改变生态系统中碳的自然循环，而不是直接的人类影响。永冻层的碳库是目前人类活动每年输入到大气中的二氧化碳的100多倍，冰点的阈值表明，突变是可能的。这项侧重于放射性碳的研究和教育计划旨在更广泛地了解陆地生态系统是否会加速或减缓未来的气候变化。

Enough carbon is contained in soils and permafrost of northern ecosystems to double current carbon dioxide in the atmosphere. Because of the size and nature of the permafrost carbon pool, decomposition of previously frozen, old organic carbon is one of the most likely positive feedbacks from terrestrial ecosystems to climate change in a warmer world. This project uses radiocarbon measurements as a unique fingerprint for detecting the loss of old soil carbon in combination with an ecosystem-scale field manipulation to determine controls over the release of permafrost carbon. This high-precision isotope research is paired with the continued development and teaching of an intensive short course designed to expose students to the emerging technology of accelerator mass spectrometry for measuring radiocarbon. Increased numbers of radiocarbon measurements combined with more researchers skilled in the interpretation of this data offers great promise towards detecting changes in ecosystem and global carbon cycling. Climate change is altering the world in which we live. At present, increasing greenhouse gases responsible for climate change are largely a result of human activities. However, climate change may alter the natural cycling of carbon in ecosystems far from direct human influence. The permafrost carbon pool is more than 100 times the current annual inputs of carbon dioxide into the atmosphere from human activity, and thresholds at the freezing point indicate that abrupt changes are possible. This research and education plan focusing on radiocarbon is aimed at understanding more broadly whether terrestrial ecosystems will accelerate or mitigate future climate change.