气候变化本身正在日益助长气候变化。温室气体浓度上升正在推动全球气温上升，引发了我们在气候模型或减排目标中尚未充分考虑的危险反馈回路。
长期以来，科学家们一直警告说，气候变暖将以各种方式推动进一步变暖，但越来越多的观测和研究终于让人们更清楚地认识到这些级联效应的强大程度。而且，通过扩展，他们展示了本世纪地球变暖的速度有多快。
9月份发表在《环境研究快报》上的一项研究综合了以往论文的结果，发现仅从融化的永久冻土、加剧的野火、更热的湖泊和水库以及更湿润、更温暖的湿地释放的额外二氧化碳和甲烷就可以推动本世纪全球平均气温上升0.2°C至0.4°C。这将超过建模者已经期望的工业化前水平上的2.6°C变暖……
主要的联合国气候报告评估了各种排放情景下地球可能变暖的程度，其中没有一个模型能够解释所有这些反馈效应。其中许多不包含任何内容。这给我们对未来几十年世界实际可能变暖的程度以及各国需要以多快的速度削减排放量以保持在关键边界内的理解留下了一个巨大的盲点。
发表在《三月份的一个地球》上的一项单独分析研究了反馈问题对我们的国际气候目标意味着什么，得出的结论是，世界可能比人们普遍认为的要远得多。它发现，只有三个区域变暖驱动的排放源–永久冻土融化、北方森林火灾增加和热带湿地变暖–可能会在地球持续破坏之前缩短多达25%的时间。
Our climate models and the UN’s reports clearly need to be updated to better represent these effects. Nations must also step up their efforts to reduce emissions to reflect this improving understanding of the dangers we face, says Sam Abernethy, the lead author of the paper and a climate scientist at Spark Climate Solutions, a San Francisco–based nonprofit research group.
At least some of this is starting to happen. Spark kick-started an initiative, called theWarming-Induced Greenhouse Gas Emissions Model Intercomparison Project, through which more than 20 international teams are running the same set of analyses on different models to develop greater understanding of feedback effects’ potential power. Researchers involved hope that the UN will incorporate those results into its next major climate assessment, due o…
But what is already clear is that the planet is rapidly warming and that nations haven’t done nearly enough to cut fossil-fuel pollution. And even if we did manage to halt it, warming-driven emissions could continue.
So a number of the research groups involved in the recent studies have started to explore what nations could do to get feedback emissions under control. Scientists at the Woodwell Climate Research Center in Massachusetts are, for example, investigating the possibility of preventing fires or rapidly detecting them and putting them out when they threaten to burn the vegetation and soil that help insulate particularly carbon-rich wedges of permafros…
Several startups are also exploring possibilities. They’re looking intosuppressing the lightning strikesthat are igniting more and more fires in high latitudes, placing synthetic mats above permafrost to prevent it from melting, and deploying autonomous drones to quickly suppress potentially high-emissions fires before they burn out of control.
Investigating all these ideas is worthwhile. But researchers are only in the earliest stages of figuring out how big a dent in emissions any such efforts could achieve across sprawling global ecosystems undergoing massive transformations.
The surest path to reducing the effect of warming-driven warming remains the one we’ve known all along: breaking society’s addiction to fossil fuels.
This article is from The Spark,MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday,sign up here.
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