Collaborative Research: P2C2--Implications of the Early Anthropogenic Hypothesis

这是一个继续检验早期人为假说的项目，该假说认为，人类早期的农业活动改变了陆地的碳循环，导致大气中二氧化碳和甲烷的净增加，抵消了全新世(过去10,000年)期间的自然下降。这一假设是基于对轨道气候变异性的观察。在以前的间冰期，大气中的二氧化碳和甲烷很早就开始下降，导致降温，最终形成冰川。在这方面，全新世是一个异常值，因为大气中的温室气体从全新世中期开始增加到17世纪中期的工业化前水平。人们对此存在很大的争论。基于人均土地使用发生变化的新信息，该项目将测试这是否可以解释在全新世观察到的温室气体的增加。它将引发过去6000年来一系列新颖的大气环流实验，将预期的自然变化与可能由人为影响引起的变化进行比较。研究人员将使用耦合环境系统模型(CESM1)，并将结果与全新世的观测数据进行比较。由于存在争议，早期的人类假说在古气候学领域产生了许多研究活动，产生了专门的研讨会、期刊卷、畅销书和公开讲座。

This is a project to continuing testing aspects of the Early Anthropogenic Hypothesis, the conjecture that early agricultural practices by humans altered the terrestrial carbon cycle, causing a net increase in atmospheric CO2 and methane that offset a natural decline during the Holocene (the last 10,000 years). The hypothesis is based on observations of orbital climate variability. During previous interglacials atmospheric CO2 and methane began to decline early, leading to cooling and ultimately glacial inception. The Holocene is an outlier in this regard because the greenhouse gases increase in the atmosphere from the mid-Holocene to preindustrial values in the mid 1700s. There is great debate about why.Based on new information that per capita land use has changed, the project will test whether this can account for the rise in greenhouse gases observed during the Holocene. It will invoke a series of novel general circulation experiments for the last 6000 years, comparing the expected natural changes with those that might have been caused by anthropogenic impacts. The researchers will use the Coupled Environmental System Model (CESM1) and compare the results with observational data for the Holocene.Because it is controversial, the Early Anthropogenic Hypothesis has generated much research activity in the field of paleoclimatology, resulting in dedicated symposia, journal volumes, popular books and public lectures.