Gabriel Levy made the point that scientists are not infallible.
Some are more sceptical than others about the Intergovernmental Panel on Climate Change (IPCC), but all see it as an essential outlet for their research.
When pushed to question some of the IPCC’s ludicrous assumptions on negative emissions technologies, some are readier than others to criticise.
These were my impressions from an all day conference in London yesterday, where scientists presented the IPCC’s three recent reports – on limiting warming to 1.5 degrees, on oceans and ice sheets, and on land and agriculture.
All the scientists who spoke had felt a shot in the arm from the school climate strikes and Extinction Rebellion. “People now feel the urgency in a more visceral way”, Andy Challinor of Leeds university said, opening the event.
Earth, from space. No land is visible because that is the Pacific Ocean. Corinne Le Quere showed
this photo at yesterday’s conference: a reminder that the oceans cover 70% of the earth’s surface
Speakers repeatedly urged political and social action, which they are convinced can avert the worst impacts of global warming. But there was no mention of radical social change: the appeals were, rather, for “joined-up government policy”.
The event was organised by the Royal Meteorological Society of the UK. It was free to get in and open to all. There was a deluge of useful information, clearly and thoughtfully explained. (The presentations and other relevant stuff are on its web site here.)
To be honest, I could not understand why it wasn’t over-booked, and was disappointed that there were empty seats. One scientist I talked to in a coffee break saw it differently: he had been at previous “tell-the-public” events that attracted just a handful of non-scientists, and was pleased by the turnout.
Science includes uncertainty
Media reports often miss the uncertainties in climate science, because the scientists provide sound-bites designed to combat climate science denial. But the uncertainties were mentioned in the frank, open discussions at yesterday’s event.
The scientists basically have no clue as to whether, over the 21st century, it will turn out bad, extremely bad, or catastrophic – for one thing, because that depends to a large extent on human society and how it acts.
Mike Meredith of the British Antarctic Society, introducing the IPCC report on oceans and the cryosphere (that’s ice, to us non-scientists), said: “The level of sea level rise [in coming decades] depends on choices we make. There are strong, policy-relevant issues.”
London, where the event was taking place, will face sea level rise of anything between 29 cm and 115 cm by 2100. “The greatest contribution will coming from melting ice sheets and glaciers. The greatest uncertainty is Antarctica.”
The IPCC report calls for “timely, ambitious and coordinated action”, Meredith added, and should be used to “empower people, communities and governments”. Many of the speakers used similar phrases.
Mat Collins of the Exeter university, asked about the speed with which the Arctic could become ice-free, said: “If we stopped emitting carbon today, we might get some ice back.” That will not happen, so: “The answer is: we do not know.” There are multiple feedbacks, some positive, some negative.
Collins said that the idea of rapid destabilisation of marine ice sheets had been under discussion in the IPCC group that drafted the oceans report. “We feel that the science is uncertain. If it wasn’t in the headline statements, it doesn’t mean we didn’t think about it. It means the science wasn’t clear.”
Don’t forget, dear readers, that, despite these difficulties, the IPCC report is frightening enough. The summary for policymakers says:
Between 1979 and 2018, Arctic sea ice has very likely decreased for all months of the year. September sea ice reductions are very likely 12.8 ± 2.3% [that is 12.8%, plus or minus 2.3%] per decade. These sea ice changes in September are likely unprecedented for at least 1000 years. Arctic sea ice has thinned, concurrent with a transition to younger ice: between 1979 and 2018, the areal proportion of multi-year ice at least five years old has declined by approximately 90% (very high confidence).
Feedbacks from the loss of summer sea ice and spring snow cover on land have contributed to amplified warming in the Arctic (high confidence) where surface air temperature likely increased by more than double the global average over the last two decades.
The words in italics indicate the scientists’ consensus view about how sure they are of each prediction.
Over the long term (the next two or three centuries), the sea level rise that scares the scientists most is not from the Arctic, but from the Antarctic ice sheet melting. (I also wrote about this here.)
Jane Rumble, a scientist who works at the UK Foreign Office, said it is “quite likely” that the western Antarctic ice sheet will collapse. “Once it’s gone, that’s not going to re-grow. It will not come back.” Asked whether there was any point to international climate agreements, she said: “Well, if it wasn’t on the governments’ agenda, governments wouldn’t insist on studying, for example, the rate of melt of the Thwaites glacier [a key element of the west Antarctic picture.]”
Projections of sea level rise and ice mass loss from the IPCC oceans and cryosphere report.
Blue = the IPCC’s RCP 2.6 scenario, which assumes that action is taken to tackle climate change.
Red = the RCP8.5 scenario, which assumes “business as usual”
Rumble explained how she had been to an international meeting of government officials and presented research from the Grantham Institute on the effect of warming. The Japanese and Chinese delegates “denied that warming was happening at all”, and the American delegates “could not comment”. “We could not get the research endorsed.”
I am not blind to the fact that the UK government, Rumble’s employer, is anxious to paint itself as leading the fight on climate, although its policies (discussed elsewhere on this blog) show otherwise. But her insights on Antarctica, on oil exploration in the southern ocean, and other issues, were valuable.
Questions about NETs
From the audience – a pretty well-informed mix of students, campaigners, researchers in related areas and others – the biggest suspicion of the IPCC (which I share) concerned the assumptions in its scenarios about the large-scale future use of negative emissions technologies (NETs).
Many people, including many climate scientists, think these are drastically inflated, to make the scenarios look as though warming can be limited with less rapid action to cut fossil fuel emissions than would otherwise be needed.
Answering a question on this, Philip Williamson of the University of East Anglia, an oceanographer, said that the drafting group for the IPCC oceans report was “instructed not to consider NETs” (which feature in the larger five-yearly IPCC assessment reports). “There are a few paragraphs on ocean fertilisation. It’s quite speculative.”
He added: “Personally I don’t think they are going to work.” In general, large scale geo-engineering solutions do not have “political and public acceptance”.
Supposed climate “solutions” such as planting seaweed – claimed to be effective for soaking up carbon – should not be called solutions, “unless you put double quotation marks around it”,
Williamson said. Whereas seaweed rots and the carbon sequestrated ends up back in the atmosphere, mangrove forests have roots in the sediment and retain carbon more effectively.
Land mammals by weight. Andy Challinor showed this to yesterday’s conference:
a reminder of the devastating human impact on land
Pete Smith of Aberdeen university, a soil and ecosystems researcher, said bluntly: “If we use an area the size of India for BECCS, then we no longer have that area for food production.”
If BECCS was ever used on the scale implied by IPCC scenarios, “that would mean we are in big trouble”, he added.
The criticism of the IPCC was implied, not explicit. It was left to an audience member, in another session, to denounce the use of BECCS in the scenarios as “a fantasy”.
Perhaps the ultimate audience question was: “It’s so strange to hear this report. Why is this not reacted to? Why is there not an emergency? Why no Manhattan-style project?”
Corinne Le Quéré of the University of East Anglia, an oceanographer and one of the founders of the Global Carbon Project, said this was a good question. “How many IPCC reports do we need?”
Le Quéré said that over the last twenty years she had battled against climate science deniers – and now witnessed the rise of the Fridays for Future movement and Extinction Rebellion. There is “no voice in the middle”, and what government actions are taken are “not at the necessary scale”.
There had been “incredible support” for climate action, she said, but also opposition to government measures – such as by the French yellow vests and Dutch farmers, who demonstrated against diesel price rises, and demonstrators in Ecuador who opposed the removal of subsidies.
This showed that “transition needs to be fair” and people had to be won over.
In my view, this went to the heart of the conference’s politics. Most of the speakers saw government, and business, as the prime movers of political change. For Le Quéré, the most pressing measures to forestall climate change are market-based ones, and government’s job is to balance the interests of those penalised by them with those who want action on climate.
This is a false dichotomy. It takes as given neoliberal economic policies, such as those of the French government that triggered the “yellow vests” protests.
There was no suggestion that radical social change that could be combined with measures on climate change, in such a way as to penalise the big corporations that bear the lion’s share of the responsibility for it.
Le Quéré’s view was, I think, representative of the scientists at yesterday’s conference. Many of them complained that government policy was ineffective because it was incoherent, and that different government departments were moving in different directions. But no-one dared breathe the word “regulation”, which is surely a basic minimum for any effective climate policies.
It is not that climate scientists do not talk about these things. Some are politically outspoken: in the UK, most obviously, Kevin Anderson of the Tyndall Centre at Manchester university. In 2013, the centre organised a more explicitly political event than yesterday’s, a “radical emissions reduction conference”. (The word “radical” referred both to swingeing emissions cuts and the policies needed to produce them.)
Campaign organisations and social movements could, and should, have picked that initiative up and run with it, in my view. We might have found ways of widening the space for dialogue between scientists and movements. We didn’t, and that’s our collective failure.
Together is better
My humble suggestion would be that we who are active in social movements try harder to work together with climate scientists.
It has become fashionable among some climate campaigners simply to denounce the IPCC as fundamentally flawed, and quote only those scientists who publish more radical policy proposals. I think that’s a bad mistake – not because such proposals are wrong, or because we should read the IPCC reports uncritically, but because we should engage with the scientists whose work is aggregated there.
Science is not neutral. It is done in a social context; the power and wealth that dominates society also dominates science; and those relations are played out not only through the IPCC but through the whole university system.
But, while constrained by that context, climate scientists are doing work on which all of us depend. The event yesterday was a reminder of the titanic efforts they put in, the incredible complexity of the process – and also of the way that all sorts of pressures, from departmental memos to high-level political pressure on the IPCC, are used to control their work.
Another lever is funding by fossil fuel companies – an issue raised at yesterday’s event by a student campaigner who challenged Emily Shuckburgh of Cambridge university about a recent £6 million grant from Shell to some of her colleagues.
The challenges are not (usually) about outright censorship, but about massaging the message, fitting the science in with economic arguments that slot into the neoliberal agenda, and imposing political assumptions that gel with governments’ attempts to avoid acting on the consequences of the science.
This is a difficult battle. Scientists and social movements should fight it together.
■ Climate change must be a thing. It’s on prime time TV (April 2019)
■ Climate scientists go for “human tipping point” (May 2014)
■ Stop tailoring global warming scenarios to make them “politically palatable” (interview with Kevin Anderson, July 2013)
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