The projected timing or climate departure from recent variability

摘要

对变暖的预测现在是气候模拟工作中的一项固定内容。Camilo Mora等人将这些模拟结果综合起来估计目前正在发生当中的变暖什么时候会超过历史气候可变性的边界。根据有关未来温室气体排放的假设，这种情况将会在21世纪中期到后期的某个时候发生。这一标志性事件可能会首先在热带发生，那里的历史可变性是低的，而生物多样性则最高。新的预测表明，热带那些经常在经济上有困难的地区将面临要迅速适应气候变化的生物效应的最大负担。在为这篇论文配发的一篇News & Views文章中，三位气候学家讨论了这些结果的意义。%Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift beyond historical analogues. Here we present a new index of the year when the projected mean climate of a given location moves to a state continuously outside the bounds of historical variability under alternative greenhouse gas emissions scenarios. Using 1860 to 2005 as the historical period, this index has a global mean of 2069 (±18 years s.d.) for near-surface air temperature under an emissions stabilization scenario and 2047 (±14 years s.d.) under a business-as-usual' scenario. Unprecedented climates will occur earliest in the tropics and among low-income countries, highlighting the vulnerability of global biodiversity and the limited governmental capacity to respond to the impacts of climate change. Our findings shed light on the urgency of mitigating greenhouse gas emissions if climates potentially harmful to biodiversity and society are to be prevented.