Higher CO2 concentrations increase extreme event risk in a 1.5 °C world
Higher CO2 concentrations increase extreme event risk in a 1.5 °C world
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DOI：
10.1038/s41558-018-0190-1
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发表时间：
2018-07-01
影响因子：
30.7
通讯作者：
Allen, Myles R.
中科院分区：
文献类型：
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作者：
Baker, Hugh S.;Millar, Richard J.;Allen, Myles R.
《巴黎协定》（1）的目标是“努力将气温上升限制在工业化前水平以上1.5摄氏度。“然而，有人认为，仅靠温度目标不足以限制与人为排放相关的风险（2，3）。在这里，使用合奏的模式模拟，我们表明，大气中二氧化碳的增加，甚至更可预测的后果排放比全球气温上升，有显着的直接影响北方半球夏季温度，热应力和热带极端降水。因此，在一个迭代的气候减缓制度，只针对一个特定的温度目标，一个意想不到的低气候响应可能有相应的极端事件的“危险”的变化。因此，较高的CO2浓度对极端气候的直接影响大大降低了碳预算的上限，并突出表明在制定允许排放量时需要明确限制大气CO2浓度。因此，在未来的气候政策中，以明确限制大气中二氧化碳浓度来补充全球平均温度目标，将限制影响力大的极端天气的不利影响。
The Paris Agreement(1) aims to 'pursue efforts to limit the temperature increase to 1.5 degrees C above pre-industrial levels.' However, it has been suggested that temperature targets alone are insufficient to limit the risks associated with anthropogenic emissions(2,3). Here, using an ensemble of model simulations, we show that atmospheric CO2 increase-an even more predictable consequence of emissions than global temperature increase-has a significant direct impact on Northern Hemisphere summer temperature, heat stress, and tropical precipitation extremes. Hence in an iterative climate mitigation regime aiming solely for a specific temperature goal, an unexpectedly low climate response may have corresponding 'dangerous' changes in extreme events. The direct impact of higher CO2 concentrations on climate extremes therefore substantially reduces the upper bound of the carbon budget, and highlights the need to explicitly limit atmospheric CO2 concentration when formulating allowable emissions. Thus, complementing global mean temperature goals with explicit limits on atmospheric CO2 concentrations in future climate policy would limit the adverse effects of high-impact weather extremes.