Nicholas Stern

03/09/2009

‘We were too cautious… we underestimated the risks from global warming’

Stern – a Knight, Lord and Fellow of the British Academy – was chosen by Gordon Brown to carry out a review of potential economic impacts of climate change in 2006. As the Copenhagen Climate Conference approaches he tells The Big Issue that the planet is in much more danger than he anticipated

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Did the Stern Review, released in 2006, underestimate the scale of the difficulties we face?
I think we probably did underestimate the risks. CO2 emissions have been growing faster than we assumed and the absorptive capacity of the planet – the oceans and forests – seems less than we thought. We were relying on the evidence of the IPCC [Intergovernmental Panel on Climate Change], and the IPPC is quite cautious about the kind of risks they include. If they couldn’t quantify it, they would exclude it. So the thawing of tundra and the emissions of methane, for example, could be more important [than predicted]. So we were probably a bit cautious – the risks are probably a bit bigger than we said.

What do we face if carbon emissions remain unchecked?
The magnitude of the risks is very worrying. If we go on with business as usual, we’d have a 50 per cent chance of reaching, over the next century, an increase of 5C. That’s somewhere we’ve not been as a world for 30 million years. We’ve no idea how we humans could cope with that because we’ve only been around for one or two hundred thousand years. We do know that 5C the other way – during the last ice age – completely rewrote the rules of where people could live. We know enough to know the risks
are huge. The message is to cut right back
on emissions.

The Stern Review tried to show that unless we invested one per cent of global GDP per annum in measures to prevent climate change, it would eventually cost us 20 per cent of global GDP. So it’s short-term sacrifice for long-term gain?
I think that’s right, but I prefer to use the language of investment. We would be investing in new ways of doing things, which would in themselves be exciting and attractive, as well as cutting down on the unacceptable risks we’d be running if we’d didn’t do very much. We can invest in new technologies. It can bring us big returns not just in climate change but on other fronts: productivity, energy security, a cleaner environment with more biodiversity. We can actually have quite an exciting period, with a lot of opportunities. So as well as cutting back on our emissions, it can be a period of dynamism, growth and new discoveries.

How awkward is it for scientists and policy experts to recommend targets? Is there a temptation to only recommend what’s expedient?
People like me who try to analyse problems and try to propose ways forward have to start with the problems and what policies make sense. I’m not a politician – I’m a member of the House of Lords, but I’m a cross-bencher. But we do have to be sensitive to what can be done; what people find most acceptable. Our job is to outline what the range of policy options are, and allow politicians to make the choices. If there’s a framework – a constant emphasis on the amount of emissions reduction we need, where we say “look everybody, here’s where we need to get to” – then each country works out the best way of doing things.

Many people have highlighted the difficulty in curbing emissions in China, India and the developing world. Is traditional economic growth in these parts of the world inevitable?
We probably need to grow for a while. For the next few decades, the challenge of overcoming poverty does need growth in material standards. But it also needs more than that – education, access to water, health and so on. However, growth in material standards for the developing world is essential. The challenge is finding a very low-carbon way of growing for the next few decades.

Is it likely the US will pass emission reduction legislation before the international climate change summit in Copenhagen in December?
It is quite possible they will have a climate bill. Their cap-and-trade bill with some domestic targets will be a good first step for the US. If they do get it through before Copenhagen, it would give the whole process a tremendous boost. I know that’s what they [the Obama administration] are trying to do. Their plans after 2020 will be important too, as will their plans for technology investment, support for the developing world and stopping deforestation.

Are you in favour of a new generation of coal power stations in Britain? The controversial Kingsnorth plant proposal involves traditional coal-fired units.
I think it would be quite irresponsible to have any new coal power plants without carbon-capture storage. The technology is there in prototype on a small scale, so the challenge is to move to a bigger scale. We can only find out about the potential problems by trying it. The UK and Europe will be very important in that, as will Australia and the US. We need a lot of demonstration on how it can work.

Are scientists getting closer to a detailed mapping of how a hotter planet will effect each region of the world?
We are getting closer, but it’s tough to know precisely. It’s much easier to estimate at the global level – the overall amount of greenhouse gases and temperature changes. When the temperature changes get translated into changes to the climate and environment it does get quite complex and scientists are still working on these things. If you’re talking about predicting to a few square kilometres, which you’d have to do if you’re talking about the flood plains in London for example, it’s an enormous task to model the entire globe like that.

Do any of the geo-engineering schemes, to alter the amount of CO2 in the atmosphere, excite you?
I think these are the kinds of things we should research, as long as they’re not reasons to back off from our emissions reduction targets. There are things like biomass with carbon capture and storage. If we grew a lot more of our fuels in forests, in a managed way, and if we burned a lot of [agricultural] waste from rice and wheat [production] and capture the carbon emitted this way, then we could probably use bio-fuels a lot more. I have some friends in Columbia University who are investigating how to get the carbon out of the air and into rocks. Some people in California are hoping to make building materials out of CO2. There are lots of exciting experiments. Let’s hope some of them work.

Should we be concerned some schemes may have unintended consequences?
I do worry about people who want to shoot dust in the air to have less solar energy coming in, or messing around with the ocean. The possibility that these things could be tried by one or two countries could be very undemocratic. There are big, difficult issues.

Are you optimistic we can keep global temperature at less than 3C hotter?
Yes, I think the target should be keeping it at a maximum of 2C hotter. I think we’ve got a decent chance. It involves people being collaborative; pulling together. We’ve got to the point where the politics have changed sufficiently, that we have a good chance of getting there. We would be derelict as a country, as a world, if we didn’t.

by Adam Forrest