The end of the world is no longer a fanciful hypothesis. It is the most plausible scenario. In the last week, the UN Environment assembly announced its finding that, even if the Paris Agreement targets were met, global temperatures would rise by three to five degrees Celsius above pre-industrial levels.

Worse, even if all carbon emissions stopped immediately, the Arctic would be 5 degrees warmer at the end of the century than in the period between 1986 and 2005. The Arctic, that “Ice Temple of the polar regions” as the Norwegian explorer Fridtjof Nansen dubbed it, is particularly sensitive to global heating. As the Cambridge polar researcher Peter Wadhams has shown, the “Arctic death spiral” is well underway. This ice will soon disappear, beginning with an ice-free September any year now.

The loss of ice-cover reduces albedo, wherein solar radiation is reflected back into space. More dark water surface absorbs heat rather than deflecting it. Thawing permafrost releases warming methane into the atmosphere. The warming of the oceans, coupled with their ongoing carbonic acidification due to carbon emissions, will kill off a lot of marine life. The last of the remaining coral will be bleached, thus destroying one of the most biologically productive areas of the planet. It will also kill much of the phytoplankton that produce about half of the oxygen we breathe. The simple act of breathing will most likely become far more effortful, far more of a struggle, in the future.

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Every ecological crisis in the ‘web of life’ impacts on every other. Consider some other recent findings. As a research team at the MIT has found, billions would regularly suffer deadly heatwaves by 2070, and half a billion would be struck by temperatures that would kill in the shade within six hours. Last year, the UN announced that it will take just 60 harvests for the erosion of fertile top soil to make the feeding of humanity impossible.

This exacerbates what one research team calls “biological annihilation”, the terrifying loss of vertebrate populations amid the sixth mass extinction. Previous mass extinction events have taken place in pulses lasting for tens of thousands of years, separated by hundreds of thousands of years. Our current mass extinction event is faster: 60 per cent of animal populations have been wiped out since 1970. All of this, combined with dropping insect biomass, desertification and more regular flooding and weather disasters, will likely congeal with capitalism’s regular crises to produce chronic and worsening breakdowns in the means of life. In the short to medium term, that raises dark questions about the political future. In the long term, it suggests that the chances for human survival are very slim.

As Christophe Bonneuil and Jean-Baptiste Fressoz have shown, we knew about these issues all along. And as the writer David Wallace-Wells points out, the majority of carbon emissions in the entire history of humanity have taken place since 1992: after the first UN climate framework for climate change was agreed, and during the reign of Kyoto and Paris. Even the UN’s finding is not entirely new. Previous studies have discovered that, on average, Paris Agreement measures would lead to 3.7 degrees of warming. What is different now is that the estimate is official. Previous official estimates have tended to systematically underestimate the extent of Arctic melting, thus unfortunately reducing the pressure to do anything about it.

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World powers view this disaster as a commercial and military opportunity to be deliriously pursued. Nato conducts grandstanding exercises in the region, the US and Canada invest in new fleets of ice-cutters, Denmark successfully trials its first commercial voyage in the transpolar sea route, and Russia re-opens military bases. The British government anticipates $100bn worth of investment in the new, blue Arctic, while the US looks forward to mining vital oil and gas reserves hidden under the thinning ice. This is not that different in practice from the Trump administration, which admitted that it expected a catastrophic 4 degrees of global warming by 2100, but only in order to justify ditching fuel-efficiency standards as a waste of time. Since the planet is doomed, capitalist nihilism seems to suggest, we may as well party now.