Nature reports:

Humanity probably isn’t going to prevent Earth from at least temporarily warming 1.5 °C above pre-industrial levels — but aggressive action to curb greenhouse-gas emissions and extract carbon from the atmosphere could limit the increase and bring temperatures back down, according to the latest report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC). The report makes it clear, however, that the window is rapidly closing, and with it the opportunity to prevent the worst impacts of global warming. Above the 1.5 °C limit — set by the Paris climate agreement in 2015 — the chances of extreme weather and collapsing ecosystems grow.

“The IPCC tells us that we have the knowledge and technology to get this done,” Inger Andersen, executive director for the UN Environment Programme, said at a press conference to release the report. “But increased action must begin this year not next year, this month not next month, and indeed today, not tomorrow.”

Approved by 195 governments after a marathon negotiating session that ran over schedule by two days, the roughly 2900-page report focuses on options for curbing emissions and mitigating the impacts of global warming. The document, compiled by hundreds of scientists across 65 countries, is the last of a trilogy comprising the IPCC’s sixth climate assessment, with the first two reports covering the underlying science and impacts of climate on humans and ecosystems. [Continue reading…]