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

这是一个继续测试早期人为假设的项目，该假设认为人类早期的农业活动改变了陆地碳循环，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）的自然下降。 这一假设是基于对轨道气候变异性的观测。 在以前的间冰期，大气中的二氧化碳和甲烷开始下降，导致冷却和最终的冰川开始。 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增加到18世纪中期的工业化前值。 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全新世期间观测到的温室气体增加。 它将调用一系列新的大气环流实验在过去的6000年，比较预期的自然变化与那些可能已造成的人为影响。 研究人员将使用耦合环境系统模型（CESM 1），并将结果与全新世的观测数据进行比较。由于早期人为假设存在争议，因此在古气候学领域产生了许多研究活动，导致专门的研讨会，期刊卷，流行书籍和公开讲座。

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.