Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA.
Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia.
Science. 2020 Feb 21;367(6480):907-910. doi: 10.1126/science.aax0504.
Permafrost and methane hydrates are large, climate-sensitive old carbon reservoirs that have the potential to emit large quantities of methane, a potent greenhouse gas, as the Earth continues to warm. We present ice core isotopic measurements of methane (ΔC, δC, and δD) from the last deglaciation, which is a partial analog for modern warming. Our results show that methane emissions from old carbon reservoirs in response to deglacial warming were small (<19 teragrams of methane per year, 95% confidence interval) and argue against similar methane emissions in response to future warming. Our results also indicate that methane emissions from biomass burning in the pre-Industrial Holocene were 22 to 56 teragrams of methane per year (95% confidence interval), which is comparable to today.
永冻土和甲烷水合物是大量的、对气候敏感的古老碳储存库，它们有可能在地球继续变暖的情况下释放大量的甲烷，甲烷是一种强效温室气体。我们展示了末次冰消期（现代变暖的部分类似物）冰芯中甲烷的同位素测量值（ΔC、δC 和 δD）。我们的结果表明，古老碳储存库对冰消期变暖的甲烷排放很小（<19 太吨/年，95%置信区间），这与未来变暖时的类似甲烷排放情况相矛盾。我们的结果还表明，工业前全新世生物质燃烧的甲烷排放量为每年 22 到 56 太吨（95%置信区间），这与今天的排放量相当。
