Collaborative Research: Testing Early Anthropogenic Effects on Climate

该奖项支持使用大气环流模型来测试这一观点的研究，即自大约11,000年前管理农业出现以来，人类开展的活动向地球大气中添加了大量二氧化碳(CO2)和甲烷。研究人员将试图模拟一个更凉爽的世界，这个世界将存在于今天，没有前工业时代和工业时代的温室气体排放。研究人员还将研究在工业化时期之前对欧亚森林进行大规模砍伐的影响，并分析在温室气体浓度更低、更凉爽的世界中短期气候变化的影响。作者最近发表的研究表明，大约11,000年前人类进行的活动向大气中添加了大量的二氧化碳和甲烷。通过大气气体浓度与数千年来流行的自然循环变化的背离，可以检测到人类大量排放这些气体。研究人员假设，如果在全新世中晚期，二氧化碳和甲烷的自然减少占主导地位，大气中的温室气体浓度将降至自然极限，地球将比今天凉爽得多。一系列证据表明，今天加拿大东北部的冰盖可能正在扩大。这表明，工业化前人类活动排放的温室气体使气候变得太热，不适合冰川作用的开始。

This award supports research using general circulation models to test the idea that activities undertaken by humans since the advent of managed agriculture approximately 11,000 years ago have added significant amounts of carbon dioxide (CO2) and methane into the Earth's atmosphere. The researchers will attempt to simulate a cooler world that would exist today in the absence of pre-industrial and industrial-era greenhouse emissions. The researchers will also examine the impacts of large-scale clearance of Eurasian forests prior to industrial periods and analyze the impact of short-term climatic variations in a cooler and lower greenhouse gas concentration world. Recently published research by the authors suggests that activities undertaken by humans about 11,000 years ago have added significant amounts of carbon dioxide and methane to the atmosphere. The onset of significant human emissions of these gases can be detected by the departure of atmospheric gas concentrations from natural cyclic variations that have prevailed for thousands of years.The researchers hypothesize that if natural decreases in CO2 and methane prevailed during the middle and late Holocene, greenhouse-gas concentrations in the atmosphere would have fallen toward their natural limit and the Earth would be a considerably cooler place than it is today. One line of evidence suggests an ice sheet would be growing today in northeast Canada. This suggests that greenhouse-gas emissions from pre-industrial human activities kept climate too warm for glaciation to begin.