What will “success” at COP26 look like? Glasgow is different from Paris: it is not about signing a single treaty, but about the sum of its parts: the accumulated pledges of each country, the Nationally Determined Contributions (NDCs). Dr Tamsin Edwards from the Department of Geography shares her thoughts about the global climate summit.

“What’s COP?”, asked my friend last week. It’s a bit unfair of me to quote him: he lives abroad, where media coverage is likely to be less blanket-like than in the UK; I didn’t use the full acronym “COP26”; and I gave no context (in fact, he was asking about my health).

But it’s a useful reminder that other people’s worlds are not revolving around the two week event that started today in Glasgow. For many of us working in climate change, life is currently consumed by COP26: reading about it, worrying about it, teaching about it; organising and writing talks for events there and elsewhere; talking to the news and recording podcasts; writing blog posts and opinion pieces about…well, what, exactly?

What will “success” at COP26 look like?

So I suppose the obvious reply might be: COP26 will be a success if climate scientists crunch the numbers of the final NDCs and find the predicted warming successfully meets the Paris Agreement target. But this is difficult to define, for a few reasons.

First, there are officially two targets: to limit warming “well below” 2°C, and to “pursue efforts” to limit at 1.5°C. So would success mean a predicted warming of 1.8°C? 1.7°C? 1.6°C?

Second, many would say these targets are not strong enough. We are already seeing changes to our weather at our current warming of 1.1°C. Each further tenth of a degree will make these changes more frequent and severe, and will make it more likely to trigger irreversible, long-term changes such as collapse of the West Antarctic ice sheet. A strong narrative has built up that we must limit warming to 1.5°C — rather than “pursuing efforts” to, which implies something higher — to limit the damage as much as possible.

Third, predictions of warming are inherently uncertain. Warming could be higher or lower than the central prediction. So only a central prediction below 1.5°C would have a better than 50:50 chance of limiting warming to 1.5°C.

Fourth, pledges are not the same as policies: the nuts-and-bolts plans of how to cut emissions using tools such as laws, taxes, grants, and encouraging behavioural change. The UK published their long-term strategy just-in-time before COP26, but few countries have plans with as many details. And they must be credible: Australia’s plans, for example, appear to be neither accurate nor physically possible. Without detailed and realistic plans for how to cut emissions by 2030, all talk is just…hot air.

And policies are not the same as reality: they must be successfully implemented, effectively enforced. There can be good surprises too, of course: faster-than-expected improvements in technology, energy efficiency, behaviour change. Future implementation is not necessarily something by which we can judge the success of COP26, but it is important to consider when assessing those Nationally Determined Contributions and any plans to achieve them.

Finally, there are other important aspects to COP26 that I haven’t discussed here (see explainer below): progress on these, or lack of, will also add to the bigger picture feelings of hope or disappointment.

I’m never a fan of binary thinking. The outcomes of COP26 will lie on a sliding scale, where it is unlikely we can reach the end — and the end is not clearly defined — but even a near-miss could be seen as successful in the stated aim to “keep 1.5 alive”. I agree with Christiana Figueres (former Executive Secretary of the UNFCCC and legend of the Paris Agreement) that some people will judge it a relative success and others an abject failure. This is inevitable when different groups are applying, at best, different value judgements and aims, and at worst, simplistic binary thinking, to outcomes that are not completely straightforward to categorise. I also agree with Chris Stark, Chief Executive of the Climate Change Committee which advises the UK government, who has said that COP26 will be seen as successful if people describe it as successful: in other words, if this is the dominant narrative emerging afterwards. We should ask, of course, which groups will determine that narrative?

It’s important to acknowledge that much of the progress of this COP26 has been made well before the meeting itself. Countries have been stating net zero aims and converting these into short-term targets and official Nationally Determined Contributions for the past few years. Without any action, we had been heading for a world 4°C warmer, or more. But given the policies we have already put in place, we are predicted to be heading for just under 3°C, perhaps a little lower. Under the official pledges updated before last month — if successfully translated into effective policies — we would limit warming to around 2.5°C. And since then, another 25 countries have updated their pledges.

Progress, yes, but by the minimum metric of limiting warming to below 2°C, nowhere near enough. Global emissions under the Nationally Determined Contributions are predicted to flatline or slightly increase this decade — China, for example, only aims to peak by 2030 — but limiting warming to 1.5°C requires us to cut global emissions by around half by 2030. By this measure, it is extremely unlikely we will see a prediction of 1.5°C warming for the final NDCs after COP26, though I remain hopeful we can improve beyond the current 2.5°C once they are all submitted and final. Keep an eye on that Climate Action Tracker

Glasgow is a very important push point, but not the only point at which we can make progress. After COP26, countries can always increase their ambition outside the five year update points of the Paris Agreement (most obviously, when governments change, as for the USA). Countries responsible for around three quarters of the world’s greenhouse gas emissions have adopted, or are considering, targets to reach net zero by 2050 or 2060: if successful, the predicted warming would be around 2°C (and if we were very lucky with the climate, perhaps as low as 1.5°C). This isn’t enough yet either, but it shows that this month’s pledges are not the only part of the story.

Longer-term, I think few people are aware that climate scientists also talk about the possibility of overshooting and then coming back. If could limit our rise above 1.5°C to just a couple of decades, this will be a better outcome than the fixed final temperature that I think most people imagine.

To put it more succinctly:

It’s never too late to do as much as we can.Greta Thunberg, The Andrew Marr Show, 31st October 2021

So 1.5 is still alive, but it’s on life support. We need to bring it out of critical care and into recovery: getting stronger month on month, year on year.

What does success look like elsewhere? I’ve been extremely fortunate over the past three years, with opportunities like co-authoring the first part of the IPCC Sixth Assessment Report and a related study, co-presenting the BBC Radio 4 series 39 Ways to Save the Planet, and co-directing an expanding MSc Climate Change.

But it hasn’t been sustainable, especially with the post-chemo fatigue (cognitive and physical) that seems persistently worse since February, so I went part-time in September. It’s been a time of tying up loose ends and passing things on. I think the hundred or so masters students are starting to settle in, with grateful thanks to co-director James Porter for helping them so much. I’ve taught four of my five weeks of climate science this term to them and our first year undergraduates. The King’s Climate Hub research network is going from strength to strength, thanks to incredible support by new coordinator Rachel Harrington-Abrams. The 39 Ways series is done. I’ve talked to interesting groups in the run-up to COP26, ranging from a huge, exciting event hosted by Stowe School (Schools’ Climate Action) to a lunchtime event for general counsel lawyers who want to make their business resilient to climate-related risks, as well as recording podcasts and other interviews (links below). In the next two weeks I’ll finish the teaching, travel to Glasgow to do a few events (also below), then round it off with a talk to a lot of vets.

I certainly haven’t yet been successful in going part-time. But I’m saying no to new events, projects and roles to make up the difference and rest after COP26. Success for me will therefore mean not a flatlining of activities, nor a slight increase, but substantial cuts: though hopefully not year-on-year until 2030.

This post was originally published on the All Models Are Wrong blog. You can read the original post and find a list of Tamsin’s COP26-related activities. She also includes an explanation of what COP26 is, or why it’s particularly important, and if you don’t know your NDCs from your UNFCCCs. It has since also been published on the King’s website here.