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Ex-IPCC Head: Prepare for 5°C Warmer World

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By Alex Kirby, Climate News Network

LONDON  The world has missed the chance to keep greenhouse gas emissions below the level needed to prevent the temperature climbing above 2° Celsius, according to the British scientist who used to chair the IPCC, the Intergovernmental Panel on Climate Change.

The scientist, Sir Robert Watson, chaired the Panel from 1997 until 2002, when he was ousted after U.S. pressure for his removal.

Watson said there is a 50-50 chance of preventing global average temperatures rising more than 3°C above their level at the start of the industrial age, but a 5°C rise is possible. That would mean the Earth warming more than it has since the end of the last Ice Age.

Scientist Sir Robert Watson said there is a 50-50 chance of preventing global average temperatures rising more than 3°C above their level at the start of the industrial age, but a 5°C rise is possible.
Credit: flickr/Several seconds

Speaking at a symposium at the London School of Hygiene & Tropical Medicine, Watson said: "All the promises in the world, which we're not likely to realize anyway, will not give us a world with only a 2°C rise. All the evidence, in my opinion, suggests we're on our way to a 3°C to 5°C world.

"Some people are suggesting that we try to geo-engineer our way out of the problem, intervening in the climate system to moderate warming.

"I'm very, very nervous about that," he said "It shows a level of arrogance that we know how to manage our environment. It certainly needs a lot of research."

Watson concluded: "There are cost-effective and equitable solutions to address climate change, but political will and moral leadership is needed, and the changes in policies, practices and technologies required are substantial and not currently under way."

Watson told the Climate News Network: "We're going to have more people in the world and they'll be wealthier, so energy demand is bound to rise.

"We look like having huge quantities of gas from shale. That can be a useful transitional tool: it emits half the carbon you get from coal. But it's not a long-term solution, unless you can use it with carbon capture and storage, CCS. I'm optimistic that CCS can work, but it's got to be shown to work, and what costs and energy penalties it will entail.

"We now know we can't rule out a possible 5°C temperature rise, and we need to start preparing for it.

"Some people are suggesting that we try to geo-engineer our way out of the problem, intervening in the climate system to moderate warming," said Sir Robert Watson.
Credit: Yale Center for Environmental Law & Policy

"When I was chairing the IPCC we were all very optimistic that we'd have a global agreement to limit emissions, though we knew it would be difficult. But we were hopeful that emissions would not go up at the tremendous rate they are rising now."

A world 5°C warmer than today could expect falling harvests in developing and developed countries, sea level rise threatening many major cities, and significant water shortages.

More species would be facing extinction (10 percent of species are thought to be at risk for every 1°C of warming), there would be more (and more intense) extreme weather, and a growing risk of abrupt and major irreversible changes in the climate system.

Watson was voted out as the IPCC's chair in 2002. The weekly New Scientist reported that the year before, shortly after the inauguration of U.S. president George W. Bush, an ExxonMobil executive wrote to the White House asking: "Can Watson be replaced now at the request of the U.S.?"

Watson is now science director of the Tyndall Centre for Climate Change Research at the University of East Anglia, UK, and chief scientific adviser to the UK Government's Department of Environment, Food and Rural Affairs.

Sir Andy Haines, former director of the London School of Hygiene, told the Climate News Network: "We're not making much progress on climate change at the moment. We need more arguments combining environment and health – cutting coal-burning, for instance, improving access to clean energy, walking and cycling instead of using cars.

"We need to look not just at population, but at consumption in the developed countries. A lot of vested interests don't want to go down that road. We can change by paying for externalities, like the adverse effects of air pollution.

"We can address the inequalities which are evident in areas like heart disease rates and diet. And we need to influence the UN's new sustainable development goals to include both health and environment indicators."

Alex Kirby, a former BBC environment correspondent, is a founding journalist of Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.


By Philip Chapman (UK)
on February 17th, 2013

5°C by when? I assume 2100, but really such predictions should come with a date.

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By Lewis Cleverdon
on February 18th, 2013

I’m hoping that scientists at Climate Central can clarify quite what Watson said, for Kirby’s report above leaves him looking both incoherent and an odd mixture of cynicism and complacency.

Watson’s expectation of a 50% chance of staying below 3.0C presumably refers to an emissions-control-only mitigation outcome, but it has to exclude both warming from the accompanying loss of the sulphate parasol and also that from the major feedbacks, of which at least six out of seven are already accelerating under just 0.8C. Given that several of the feedbacks each have the potential to dwarf anthro-CO2e outputs, it is hard to see a rationale for assuming that warming would stop at Watson’s upper bound of 5.0C.

Yet a scientist of his standing has to be aware that what happens in the latter half of this century is largely irrelevant - either mitigation is successful in its first half or our global civilization collapses into mass famine, die-off and strife. The recent report (which surely warrants a CC post) : “Food Security: Near future projections of the impact of drought in Asia” (see ‘reports’ at ) details the probability of extreme drought causing crop failures across Asia within a decade, particularly hitting Turkey, Pakistan, India and China, under about 1.0C of global warming. The resulting loss of global food security (with Asia already outbidding the West on oil, and western agriculture already under intensifying disruption) would predictably have highly destabilizing effects geopolitically, thereby diminishing the feasibility of the close global co-operation that is essential for mutual commitments to commensurate mitigation of AGW. To overlook the fact that such crop failures have begun, and are liable to become critical during the 2020s, seems like a grand complacency.

Watson’s reported dismissal of geo-engineering, characterizing as arrogant the scientists who research it, is at odds with the predicament we face. Emissions Control alone cannot touch the potentially ruinous warming in the 2020s, and longer term it patently cannot control the terminal acceleration of the feedbacks (with a 30yr timelag after a 2050 goal, it would be 2080 before anthro-warming peaked its acceleration of those feedbacks). Thus the properly supervised rapid research of both Carbon Recovery and Albedo Restoration modes of geo-engineering is pre-requisite to any chance of effective mitigation - in reality that research is now the most critical priority, as Watson ought to be well aware.

So please could some clarification be provided as to whether his speech has been fairly reported ?






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By Gary
on February 18th, 2013

I would rather another solution to rouse people from there stupor, But Governments are not the ones making the decisions everyone knows this. So i think our best option is total economic collapse this is my prefrence before ecologilcal catastrophe.

Thank you

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By Hartog van den Berg (Hobart)
on February 19th, 2013

Can somebody share this with Sir Watson?

The story of the two-degree target began in the German Advisory Council on Global Change (WBGU). Administration politicians had asked the council for climate protection guidelines, and the scientists under Schellnhuber’s leadership came up with a strikingly simple idea. “We looked at the history of the climate since the rise of homo sapiens,” Schellnhuber recalls. “This showed us that average global temperatures in the last 130,000 years were no more than two degrees higher than before the beginning of the industrial revolution. To be on the safe side, we came up with a rule of thumb stating that it would be better not to depart from this field of experience in human evolution. Otherwise we would be treading on terra incognita.”
As tempting as it sounds, on closer inspection this approach proves to be nothing but a sleight of hand. That’s because humans are children of an ice age. For many thousands of years, they struggled to survive in a climate that was as least four degrees colder than it is today, and at times even more than eight degrees colder.
This means that, on balance, mankind has already survived far more severe temperature fluctuations than two degrees. And the cold periods were always the worst periods. Besides, modern civilizations have far more technical means of adapting to climate change than earlier societies had.

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By Bob (Richmond, VA 23060)
on February 19th, 2013

I agree with an earlier commenter that this really is an incoherent speech or report of a speech.  Some of the former, I believe.  50-50 chance of warming to 5°C, maybe 3°C with no time specified.  I thought climate “scientists” had learned to make predictions so far out in the future that no one could check them, but at least gave a date.  This prediction is some indeterminate time in the future.  Since climate “science” has been short on measurable prediction success, why should we believe this?

The argument loses me when I have to accept that the climate can be controlled, kept static at some as yet to be defined set of conditions and humans suddenly cannot adapt to change after doing so for a very long time under worse climatic conditions than now.  We need better arguments and a science that makes verifiable predictions.

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By Eline van Oostrom (Amsterdam, The Netherlands)
on February 20th, 2013

In my opinion at least two of the commenters are consciously misreading or misrepresenting what little is reported about Bob Watson’s speech at the the London School of Hygiene & Tropical Medicine. Please consider this is a speech, not a report or a paper, and it contains Watson’s personal - but expert - views on the topic.

One commenter mentions: “50-50 chance of warming to 5°C, maybe 3°C with no time specified.” That is not what was actually said, and the proper wording is in the article: “Watson said there is a 50-50 chance of preventing global average temperatures rising more than 3°C above their level at the start of the industrial age, but a 5°C rise is possible.

Rather obviously this translates to a 50% chance of < 3 °C and a 50% of > 3 °C, with a possibility (!) of a 5 °C rise. Considering what little action is undertaken, Watson said, I quote: “All the evidence, in my opinion, suggests we’re on our way to a 3 °C to 5 °C world.”

When? Well, as far as I can see, Watson based his speech partly on the new CMIP5 simulations for IPCC 2013. These simulations show equilibration of temperatures under the RCP 8.5 and RCP 6.0 emission pathways considerably later than the year 2100, although RCP 8.5 already covers the 3.3 - 5.0 °C temperature range by 2100. Please note those are Global Mean Surface Temperatures: averages over land and ocean and all four seasons.

Actual temperature increases will be higher above land, and closer to the Arctic. RCP 8.5 shows a 4 - 5 degrees temperature increase over 2081-2100 above mainland USA during summer, and maybe a bit more during winter. The RCP 6.0 scenario shows only about 60% of this increase, so yes, it would make a difference.

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By Greg (London)
on February 20th, 2013

Bob, the speaker is clearly talking in relation to the IPCC goal of no more than 2degrees rise by the end of the 21st century.

Your use of scare quotes around ‘scientist’ marks you as a certain type of commenter (your quotes are meaningless- Watson is a professional scientist, there is no doubt in his job title), however I’m going to assume you’re a rational human being, and tell you two facts that do not disagree with your comment at all, and should give you pause:

1) 2 degrees warming is not ‘safe’ and is no longer even likely (it will probably be worse)
2) Uncertainty works both ways- it could be not as bad as predicted, but equally could be much worse. Recent weather trends suggest the latter, and scientists in general have a tendency to be cautious in their predictions.

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By steve jones (santa cruz, california USA)
on February 20th, 2013


5 degree increase will DESTROY our world!
We need to REDUCE CO2 to 350 now!!!!

Join Us!

Steve Jones
Santa Cruz 350


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By Frits Rincker (Holland)
on February 24th, 2013

This post is so unhelpfull. It is advertisement for shale gas, it doesn’t mention the huge food crisis that’s coming, it demoralizes and makes it seem like a viable option to have 5 degrees warming, while it’s the end of life on earth.

With 5 degrees there is no escaping methane release from oceans and tundra, oceans will be dead, soon they will turn poisonous and all things on land will die from the H2S gasses. So for an IPCC member to take some kind of intellectual distance and talk about it this way is disgusting.

If you want the scenario, which is not a doom scenario but the track we are on because we like rich people selling oil so much, is that of the End Permian Extinction.

I have a blog called

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By Copie
on March 1st, 2013

Robert Watson you are a disgrace, trying to convince gullible people that severe cold is really global warming is just sick. Get a real job where you don’t have to lie!

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