Trump is out and Biden is in, and you will hear a lot of talk about meeting that never-exceed +1.5°C limit. The blather starts today (Thursday), when the US president convenes his ‘Climate Leaders’ Summit’ (virtual), and ends in November in Glasgow with COP-26, the five-yearly United Nations climate meeting where the commitments actually get made.
But it is already clear that the Glasgow meeting cannot keep the warming under +1.5°C. That target was close to impossible when they adopted it at the last big climate summit in Paris in 2015, and that train has now left the station.
This is not a license for despair. Cutting greenhouse emissions is still important and urgent, but the issue is now also how to deal with much more dangerous warming. We will need new strategies and new technologies to contain the damage, but first – how can we know for sure that we will go through +1.5°C by 2035, or possibly even by 2030?
By the numbers. The scientific consensus is that 430-435 parts per million (ppm) of carbon dioxide in the atmosphere will commit us to +1.5°C. We are now at 415 ppm, and in an average year we put about another 2.5 ppm into the atmosphere. So we have at the most 20 ppm left to play with before we commit to +1.5°C, and we will cover that distance by 2029.
Or rather, we’ll get there by then if we don’t cut our emissions very fast. In fact, we have to cut them by half in 2030 if we want to be safe. But even in the plague year of 2020 we only cut our emissions by 7%. Most years we don’t cut them at all.
It’s the Nationally Determined Contributions (NDCs) that tell the tale. NDCs were an innovation of the Paris summit in 2015, designed to break the deadlock that had paralysed previous summits.
Instead of arguing endlessly about how much each country should cut, every country was just asked how much it was willing to cut. They’d presumably be too embarrassed to say ‘nothing’, so at least that way we’ll get something done.
By the way, this was why Donald Trump looked so foolish when he demanded to renegotiate the US emission cuts that Barack Obama had promised. There was no negotiation in 2015. Each country’s obligation was whatever it offered. The only person Trump could have renegotiated with was Obama, and only if he had a time machine.
Anyway, here we are in 2021, and theory was that at this summit (originally scheduled for 2020) every country would raise its target for emissions cuts. We need 50% emissions cuts by 2030 to stay below the +1.5°C limit. How’s that working out?
Well, Russia and the United Kingdom are the stars among the major countries, respectively promising 70% and 68% cuts in its emissions compared to 1990 (but that’s only because they massively de-industrialised in the 1990s). The whole European Union is going to do 55%. If everybody else did the same, we’d be home and dry by 2030.
But Canada says its target is 30% cuts below its 2005 level. (Not the 1990 level, you’ll note – and so far it has only cut 1% .) Japan, Mexico and Australia are all in the mid-20s, India and Indonesia won’t set a number, and China says it will try to ‘peak’ its emissions by 2030 (i.e. they will continue to grow every year until 2030).
The US promise under Obama was 26%-28% cuts, but Trump pulled out of the deal. Even if Joe Biden says the new American NDC will be 50%, and even if everybody keeps their promises, we will end up in 2030 with a global cut of 30% at best. So wave good-bye to ‘no more than 1.5°C of warming’.
What do we do now? Starting with COP-26, we start developing ways to get carbon dioxide back out of the atmosphere (Carbon Dioxide Removal – CDR), and to hold the heat down while we work on that (Solar Radiation Management – SRM). And we work as fast as we can to get our emissions down, because the other stuff is just short-term techno-fixes.
CDR and SRM were both discussed at the 2015 summit, but now we need to start spending serious money on them. We’re going to need them in the 2030s, and neither the science nor the technology will be ready overnight. Ten years might be enough. It had better be enough.