Why is this report coming out now?
When the Paris climate agreement was being negotiated in 2015, island nations facing obliteration from rising seas demanded swifter action. To get them on board, countries agreed not just to try to limit warming to well below 2°C above pre-industrial levels, but also “to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels”.
That seems reasonable
It actually took climate scientists by surprise, given that the world had already warmed by 1°C and that no countries were proposing to do nearly enough to achieve the 2°C goal. Nonetheless, it was decided the Intergovernmental Panel on Climate Change (IPCC), which was set up by the United Nations, should put together a special report to compare the impacts of 1.5°C with 2°C, and what it would take to achieve it. It is a synthesis of all published research up to 15 May this year, so nothing in it should come as a surprise.
Presumably we’re much better off limiting warming to 1.5°C?
You . But the consequences are still severe, especially for the poorest.
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So can we limit warming to 1.5°C?
No.
It says that?
It does not use that word but came as close as this kind of report will ever get: “There is very high likelihood that under current emission trajectories and current national pledges the Earth will warm more than 1.5°C above pre-industrial levels.” This was in a later leaked draft, which instead waffled on about feasibility: “There is no simple answer to the question of whether it is feasible to limit warming to 1.5°C… because feasibility has multiple dimensions…”. Even this got cut from the final report.
Wait, scientific reports get watered down?
While the first drafts of IPCC reports are written by climate scientists, the final wording is the outcome of political negotiations among diplomats. We know from water it down.
Why can’t we limit warming to 1.5°C?
There are two aspects to this. If aliens landed tomorrow and took away all our fossil fuels, how much hotter would the planet get? And if the aliens don’t arrive, how much will we do ourselves? According to a study out in August – too late to include in the report – even if those aliens arrive. To be clear, this study does not say this is definitely the case, just that it is within the range of possibilities.
Game over, then?
Most studies suggest it is still physically possible to keep warming below 1.5°C, or at least to get back down to this level later this century after overshooting it. But achieving this would not only require emissions to decline very rapidly – which would take radical and unprecedented change in every aspect of our lives including leaving oil and coal reserves in the ground –  we would have to actually remove CO2 from the atmosphere.
So we can just do that?
“Even if it is technically possible, without aligning the technical, political and social aspects of feasibility, it is not going to happen,” says Glen Peters of the Center for International Climate Research in Oslo. For now, global emissions are still increasing and we have yet to find a plausible way to remove huge quantities of CO2 from the atmosphere. “There is a high chance that the level of CO2 removal [required] might not be feasible,” said the early draft.
OK, forget 1.5°C. How’re we doing on that 2°C goal?
According to the report, if countries make the cuts they say they will, we’re on course for around 3°C warming by 2100, with the warming continuing after this point. The Climate Action Tracker says , based on existing policies. If countries do more and meet their Paris goals, it’s 3.2ºC.
That’s depressing…
It’s not looking good. But even if the world doesn’t meet either of the Paris targets, every reduction in emissions will help limit further warming.
This story has been updated since publication.
