We can thank our clouds for saving us from a fate worse than Venus's

Clouds are essential as they reflect and scatter sunlight back into space - but nobody knows how hot the planet can become before the clouds no longer help us.

No one wants to think about cloudy skies in August but if they’re up there, be grateful. According to research published in Nature Geoscience on 28 July, we can thank clouds for saving us from a fate worse than Venus’s.

Venus – a barren, hot planet – suffered from the “runaway greenhouse effect” when its temperature rose past a critical point. That, it seems, arose from having too much thermal insulation resulting from the heat-storing greenhouse gases in the planet’s atmosphere.

On Venus, as on earth, carbon dioxide was an important contributor. Our planet is wet and heating it creates a lot of water vapour, a far more potent insulator than carbon dioxide. The more water vapour there is, the faster warming occurs.

Once you hit the point of no return at which the runaway effect starts, it would take only a few thousand years for life on earth to become untenable.

The recently published calculations show that the Venus effect could happen here – if it weren’t for clouds. They look white and fluffy to us because they scatter light. The tops of the clouds do the same, scattering and reflecting sunlight back into space before it has the chance to warm the earth and take it into the runaway scenario.

There’s still some uncertainty in the calculations, however: we don’t know exactly how hot we can let the planet become before the clouds can no longer help us. Unfortunately, uncertainty in other areas is pushing us in the right direction to find out.

The Intergovernmental Panel on Climate Change (IPCC) will publish its fifth assessment report next year. A draft report of some of its data, leaked to the Economist, suggests that increasing carbon-dioxide levels won’t warm the atmosphere as much as we had previously thought. In 2007, the IPCC stated that concentrations of between 445 and 490 parts per million (ppm) of carbon dioxide were likely to result in a rise in temperature of 2° to 2.4° Celsius above the temperatures before the Industrial Age. The new data suggests that 425 to 485ppm would give a rise of 1.3° to 1.7° Celsius.

The Economist threw in plenty of caveats (“The two findings are not strictly comparable”; the data comes “from a draft version of the report, and could thus change”) but evidently felt the burden of reducing carbon emissions is not as onerous as it once seemed. “It is clear,” the paper declared, “that some IPCC scientists think the projected rise in CO2 levels might not have such a big warming effect as was once thought.”

As it turns out, it’s not just carbon dioxide that we need to worry about. US researchers have been mapping the gas leaks from pipelines in urban areas. Boston has more than 3,000 leaks in the pipelines that deliver gas to homes and industries. Preliminary data from Washington, DC indicates that the capital is just as prone to leaks. It’s of huge concern because methane is 25 times more potent as a greenhouse gas than carbon dioxide. If similar figures apply to every other major city with an ageing gas infrastructure, perhaps the chances of earth slipping into a runaway greenhouse effect need revising upwards.

We can be sure those figures won’t be in the IPCC report, however. As for the ones in the Economist, we’ll just have to wait and see. In many ways, it doesn’t matter: the numbers are out there now and will be put to work by those keen to make sure we don’t punish carbon emitters. Such a leak is not going to make governments feel inclined to do something about the problem – they can just keep their head in the clouds.

Sunset over Tiananmen Square after a day of heavy pollution in Beijing. Photograph: Getty Images.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 12 August 2013 issue of the New Statesman, What if JFK had lived?

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David Blunkett compares Labour membership to failed revolution “from Ukraine to Egypt”

The Labour peer and former home secretary says new members need a “meaningful political education”, and accuses unions of neglecting their “historic balance”.

There are three sorts of opposition. There’s the civil society opposition, with people campaigning in their own specific areas, people who’ve got an interest group or are delivering social enterprise or a charity. I don’t think we should underestimate that because we're going to have to hang on to it as part of the renewal of civil society.

The second is the opposition formally, within the House of Commons: those who have agreed to serve as the formal shadow ministerial teams. Because of what I’d describe as the turmoil over the last two years, they’ve either not been able to be impressive – ie. they’re trying very hard but they don't have the coherent leadership or backing to do it – or they’ve got completely different interests to what it is they’re supposed to be doing, and therefore they’re not engaged with the main task.

Then there’s the third, which is the informal opposition – Labour linked sometimes to the Lib Dems and the SNP in Parliament on the opposition benches as a whole. They’re not doing a bad job with the informal opposition. People getting on with their work on select committees, the departmental committees beginning to shape policy that they can hopefully feed to the National Executive Committee, depending on the make-up of the National Executive Committee following this year’s conference. That embryo development of coherent policy thinking will be the seed-bed for the future.

I lived through, worked through, and was integrally involved with, what happened in the early Eighties, so I know it well. And people were in despair after the ‘83 election. Although it took us a long time to pull round, we did. It’s one reason why so many people, quite rightly in my view, don't want to repeat the split of 1931 or the split of 1981.

So they are endeavouring to stay in to argue to have some vision of a better tomorrow, and to persuade those of goodwill who have joined the party – who genuinely believe in a social movement and in extra-parliamentary non-violent activity, which I respect entirely – to persuade them that they’ll only be effective if they can link up with a functioning political process at national level, and at townhall and county level as well.

In other words, to learn the lessons of what’s happened across the world recently as well as in the past, from the Ukraine to Egypt, that if the groundswell doesn’t connect to a functioning party leadership, then, with the best will in the world, it’s not going to achieve its overall goals.

How do we engage with meaningful political education within the broader Labour party and trade union movement, with the substantially increased rank-and-file membership, without being patronising – and without setting up an alternative to Momentum, which would allow Momentum to justify its existence as a party within a party?

That's the challenge of the next two years. It's not just about someone with a vision, who’s charismatic, has leadership qualities, coming forward, that in itself won’t resolve the challenge because this isn't primarily, exclusively about Jeremy Corbyn. This is about the project being entirely on the wrong trajectory.

A lot depends on what the trade unions do. They command effectively the majority on the National Executive Committee. They command the key votes at party conference. And they command the message and resources that go out on the policy or programmes. It’s not just down to personality and who wins the General Secretary of Unite; it’s what the other unions are doing to actually provide their historic balance, because they always have – until now – provided a ballast, foundation, for the Labour party, through thick and thin. And over the last two years, that historic role has diminished considerably, and they seem to just be drifting.

I don’t think anybody should expect there to be a party leadership challenge any time soon. It may be that Jeremy Corbyn might be persuaded at some point to stand down. I was against the challenge against him last year anyway, purely because there wasn't a prepared candidate, there wasn't a policy platform, and there hadn’t been a recruitment drive to back it up.

People shouldn’t expect there to be some sort of white charger out there who will bring an immediate and quick end to the pain we’re going through. I think it’s going to be a readjustment, with people coming to conclusions in the next two years that might lead the party to be in a position to fight a credible general election in 2020. I’ve every intention of laying down some good red wine and still being alive to drink it when the Labour party is elected back to power.

David Blunkett is a Labour peer and former home secretary and education secretary.

As told to Anoosh Chakelian.

This article first appeared in the 30 March 2017 issue of the New Statesman, Wanted: an opposition