The world has made more progress on climate change than you think – or than you could have predicted a decade ago

It must be painful for Boris Johnson to be a footnote, especially a French footnote, but after two very long weeks there were still only two possible outcomes at the top of the On the climate in Glasgow. A collapse in Copenhagen, putting the implementation of the Paris Agreement on hold for years. Or a footnote.

A collapse was never in anyone’s best interest, so we ended up with a footnote. A long footnote, an important footnote, but a footnote nonetheless. The Glasgow Climate Pact saw rules clarified (sort of), more funding, especially for adaptation (but still not enough), greater clarity on long-term goals and dealing with loss and damage related to climate, and progress (still insufficient) on short-term commitments.

And if we take a step back and take a look at the decades-long process that began with the United Nations Framework Convention on Climate Change, it is important, especially for tired school strikers, to realize how far we have come. .

Just 16 years ago (or, more depressingly, 0.3 ℃), in 2005, my scientific colleague Dave Frame and I gave a talk stressing that the objective of the 1992 convention to stabilize atmospheric concentrations of gases at greenhouse effect – which for carbon dioxide meant 50-80% reductions in global emissions by 2100 – was unlikely to be enough to stop global warming. Warming was primarily determined by cumulative carbon dioxide emissions, so to stop warming we would need to reduce annual CO₂ emissions to net zero.

Photo of a laptop screen displaying speaking notes
Notes from the 2005 conference, recently found on the author’s old laptop.
Myles Allen, Author provided

Later in 2005, we even gave a rough estimate of the “carbon budget,” or how much we could dump into the atmosphere by burning fossil fuels throughout the industrial era before pushing global temperatures up to- above 2 ° C: one thousand billion tonnes of carbon, which is equivalent to 3,700 billion tonnes of CO₂. The latest estimate combining historical and future allowable emissions from the 2021 global carbon budget is 3.74 trillion tonnes of CO₂.

To be fair, Dave and I were overly optimistic in that we didn’t account for the weakening of carbon sinks as soils warm and forest fires become more frequent. We thought that limiting fossil fuel emissions to this trillion tonnes would be enough for 2 ° C.

But by the time we sorted this out and published the result in 2009, with several other groups drawing similar conclusions, it was clear that we needed to limit all CO₂ emissions, including those from deforestation and not just fuels. fossils, about a trillion tonnes of carbon to limit warming to 2 ° C. And that remains the estimate today – although we continue to eat into that total budget every year that shows continue.

It wasn’t because these early groups were particularly smart or far-sighted. This is because the problem turned out to be simple. The most surprising thing about the research on how global temperatures respond to greenhouse gas emissions is the few surprises. Global temperatures continue to rise decade after decade, about exactly as expected in the late 1970s.

And the simplicity of that answer must be a factor in how the conversations at the annual UN climate summit have turned out. At COP10 in 2003, the first I attended, there were elegantly dressed young Americans walking around in pairs handing out leaflets explaining how the case for human influence was unproven and that coal was the fuel of the future.

The world has changed, and I wonder how many of these young men (they were all men) were returning to COP26 as sustainability managers of large multinational corporations, or taking their daughters to the Fridays for Future walks.

Our 2005 conference was not particularly well received – “unnecessary” is the word I remember. Perhaps this is not surprising since the title of the conference was “Stabilization 2005”, and we complained that stabilization targets were irrelevant.

Cumulative emissions since the pre-industrial era had just exceeded half a trillion tonnes at the time, so people were worried about the message that seemed to be, “Relax, we’re only halfway through.” path. Well, we’re over two-thirds of the way now.

Reasonable rating of 2 ° C

But if (and this is a big if) countries manage to honor the commitments they have made from Paris, including China’s declaration of carbon neutrality by 2060 and India’s net zero by 2070, even if serious global reductions didn’t start until after 2030, we would save (just) a trillionth of a ton of carbon.

This would give us, depending on the fate of other emissions, reasonable chances of limiting global warming to 2 ° C. Speaking at COP18 in Doha in 2012 (the next COP I attended, where the idea of ​​net zero was still seen as a bit radical), I didn’t expect to be able to write this in 2021.

Of course, this is not enough, because while global temperatures have reacted to emissions about as expected, the climate impacts associated with today’s level of warming as we exceed 1.2 ° C, turned out to be much worse than we would have predicted in 2005. These are the nasty surprises.

Small town in the flooded valley
Flooding, heat waves and other forms of climate-related extreme weather are worse than expected.
Nick_ Raille_07 / Shutterstock

So the world decided in Paris in 2015 that 2 ° C was clearly not “safe”, and we should instead aim to limit warming to 1.5 ° C. And this is where the Glasgow Pact fails.

We’ve made progress by recognizing where we want to go, not how we’re going to get there, let alone actual evidence that we started. Nations could only agree to “phase out”, not “phase out”, the constant use of coal power and inefficient fossil fuel subsidies. It’s a deal to slow down, not stop.

At least they agreed to mention fossil fuels in a United Nations climate deal for the first time. At a time when the industry has returned to record profits, there is a clear need to bring it (kicking and screaming or not) into the tent and having it play its part in the solution, not just allowing it to continue. sell the product that is causing the problem, let alone subsidize it to do so.

It is precisely because carbon dioxide accumulates in the climate system that early reductions are important. It’s like braking distance: the earlier you brake (slow global warming), the shorter your stopping distance (lower warming peak). And we don’t even know how well the brakes work.

The biggest uncertainty of all, and which they don’t talk about much at COP meetings, is that until we actually start cutting global emissions, we won’t know how difficult – or how easy it will be. -. Once we really get started, transitions often turn out to be nowhere near as costly or traumatic as feared. We can still be surprised.

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