A bombshell report in Nature Geoscience has revealed that, despite it being thought to be near-impossible, the world may actually be able to meet not just the 2°C (3.6°F) warming limit set by the Paris agreement, but it could even keep warming below the more ambitious 1.5°C (2.7°F) requested by poorer and low-lying nations.
Prior to this report, thanks to the slower-than-required pace of climate change mitigation, it was generally thought that the upper limit would be breached, perhaps as soon as 2050. One climate economist, Professor Michael Grubb at University College London, said back in 2015 that the speed of the greenhouse gas (GHG) cuts required to meet the 1.5°C target were “incompatible with democracy”.
However, thanks to some new, rigorous, cutting-edge science, he’s come around: Grubb is actually now one of the co-authors of this study.
After looking at each nation’s contribution plans to the Paris accords, the amount of carbon dioxide required to alter the global temperature, and how models calculate this, the team found that the lower limit is perfectly within reach.
As it turns out, climate models used by other studies slightly underestimate the amount of carbon dioxide emissions we have left before the temperature increase is nudged up to 1.5°C. Using the most up-to-date data on our greenhouse gas emissions, the team found that – as of 2015 – there's 20 years’ worth of extra emissions legroom leftover, based on current emission rates.
Putting it another way, we have a somewhat larger global carbon budget that we previously thought, with respect to the goals of the Paris agreement. This means that the planet has a bit more time to deal with the climate crisis.
Plenty of media outlets have erroneously (intentionally or otherwise) taken this paper as evidence that climatologists have little idea how to calculate future warming scenarios, and that global warming is an overblown phenomenon. In actual fact, this study shows that science is doing exactly what it’s supposed to be doing – correcting itself, ever so slightly, at the bleeding edge.
In this case, the correction came in the form of our carbon budget, with respect to a warming of 1.5°C. That's all. Global warming has not been overestimated, as some have claimed.
The world is still warming remarkably quickly, and we’re already seeing the dire consequences of this. However, we have potentially more room to move when it comes to dealing with it, and we may be able to save some of those low-income nations that would otherwise be doomed.
Ultimately, it shows that the Paris agreement isn’t a lofty political ideal, but a practical framework for saving the planet. Make no mistake – this is good news.
The study also contains a few other morsels of good news. It points out that the hypothetical damage caused by America’s withdrawal from the agreement, which it takes into account, is lower than expected. It also indicates that China and the European Union’s efforts to invest in clean energy is, and will, pay dividends.
“Our analysis suggests that pursuing efforts to limit the temperature increase to 1.5°C is not chasing a geophysical impossibility,” the authors conclude. However, they explain that it won’t be easy.
“[This] is likely to require a significant strengthening of the National Determined Contributions [to Paris] at the first opportunity in 2020” in order to prepare for the risk that the planet’s warming may jump up quickly after all. They also suggest that the world needs to “hedge against the risks of… economic, technical or political impediments.”
One huge additional caveat is necessary here: This is just one study, and science is an emergent truth decided by consensus. If this study is wrong and the others were right, it means that, at present, the world has fewer than five years to drastically cut its GHGs before the 1.5°C limit is breached.
Either way, it’s best not to be complacent. Act now or die – that’s the harsh reality of climate change, which one French environmental minister described as a future “serial killer”.
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