The Scotsman

We don’t have 12 years to act on climate change – we have to do something now

- Myles Allen

Iwas invited to speak to a group of teenagers on climate strike in Oxford recently. Like many scientists, I support the strikes, but also find them disturbing. Which I’m sure is the idea.

Today’s teenagers are absolutely right to be up in arms about climate change, and right that they need powerful images to grab people’s attention. Yet some of the slogans being bandied around are genuinely frightenin­g: a colleague recently told me of her 11-year-old coming home in tears after being told that, because of climate change, human civilisati­on might not survive for her to have children.

The problem is, as soon as scientists speak out against environmen­tal slogans, our words are seized upon by a dwindling band of the usual suspects to dismiss the entire issue. So, if I were addressing teenagers on strike, or young people involved in Extinction Rebellion and other groups, or indeed anyone who genuinely wants to understand what is going on, here’s what I’d say.

My biggest concern is with the much-touted line that “the Intergover­nmental Panel on Climate Change (IPCC) says we have 12 years” before triggering an irreversib­le slide into climate chaos. Slogan writers are vague on whether they mean climate chaos will happen after 12 years, or if we have 12 years to avert it. But both are misleading.

As the relevant lead author of the IPCC Special Report on Global Warming of 1.5°C, I spent several days last October, literally under a spotlight, explaining to delegates of the world’s government­s what we could, and could not, say about how close we are to that level of warming. Using the World Meteorolog­ical Organisati­on’s definition of global average surface temperatur­e, and the late 19th century to represent its pre-industrial level (yes, all these definition­s matter), we just passed 1°C and are warming at more than 0.2°C per decade, which would take us to 1.5°C around 2040.

That said, these are only best estimates. We might already be at 1.2°C, and warming at 0.25°C per decade – well within the range of uncertaint­y. That would indeed get

us to 1.5°C by 2030: 12 years from 2018. But an additional quarter of a degree of warming, more-or-less what has happened since the 1990s, is not going to feel like Armageddon to the vast majority of today’s striking teenagers (the striving taxpayers of 2030). And what will they think then?

I say the majority, because there will be unfortunat­e exceptions. One of the most insidious myths about climate change is the pretence that we are all in it together. People ask me whether I’m kept awake at night by the prospect of five degrees of warming. I don’t think we’ll make it to five degrees. I’m far more worried about geopolitic­al breakdown as the injustices of climate change emerge as we steam from two to three degrees.

So please stop saying something globally bad is going to happen in 2030. Bad stuff is already happening and every half a degree of warming matters, but the IPCC does not draw a “planetary boundary” at 1.5°C beyond which lie climate dragons.

What about the other interpreta­tion of the IPCC’S 12 years: that we have 12 years to act? What our report said was, in scenarios with a one-in-two to two-in-three chance of keeping global warming below 1.5°C, emissions are reduced to around half their present level by 2030. That doesn’t mean we have 12 years to act: it means we have to act now, and even if we do, success is not guaranteed.

And if we don’t halve emissions by 2030, will we have lost the battle and just have to hunker down and survive? Of course not. The IPCC is clear that, even reducing emissions as fast as possible, we can barely keep temperatur­es below 1.5°C.

So every year that goes by in which we aren’t reducing emissions is another 40 billion tonnes of CO₂ that we expect today’s teenagers to clean back out of the atmosphere

– a giant industry of the future that presents particular opportunit­ies for Scotland – in order to preserve warm water corals or Arctic ice.

Assuming people will still want to feed themselves and not turn the world over to biofuels, then scrubbing CO₂ out of the atmosphere currently costs £150£500 per tonne, plus the cost of

permanent disposal. So those 40 billion tonnes of CO₂ represent a clean-up liability accumulati­ng at a cool £8 trillion per year, more or less what the world currently spends on energy.

So here is a conversati­on young activists could have with their parents: first work out what the parents’ CO₂ emissions were last year (there are various carbon calculator­s online – the average is about seven tonnes of fossil CO₂ per person in Europe). Then multiply by £200 per tonne of CO₂, and suggest the parents pop that amount into a trust fund in case their kids have to clean up after them in the 2040s. If

the parents reply, “don’t worry, dear, that’s what we pay taxes for”, youngsters should ask who they voted for in the last election and whether spending taxes on climate change featured prominentl­y in that party’s manifesto. Get angry by all means, but get angry for the right reasons.

Action is long overdue, but to a British public sunbathing in February it doesn’t feel like an emergency. Middle-aged critics would much rather quibble over the scale of climate impacts (as if they have any right to say what climate young people should have to put up with) than talk about the clean-up bill.

Climate change is not so much an emergency as a festering injustice. Your ancestors did not end slavery by declaring an emergency and dreaming up artificial boundaries on “tolerable” slave numbers. They called it out for what it was: a spectacula­rly profitable industry, the basis of much prosperity at the time, founded on a fundamenta­l injustice.

It’s time to do the same on climate change.

Myles Allen is professor of geosystem science and leader of ECI Climate Research Programme at Oxford University. This article is republishe­d from The Conversati­on website under a Creative Commons licence.

 ?? PICTURE: JEFF J MITCHELL/GETTY ?? 0 Extinction Rebellion protesters staged a rally on Edinburgh’s North Bridge
PICTURE: JEFF J MITCHELL/GETTY 0 Extinction Rebellion protesters staged a rally on Edinburgh’s North Bridge
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