Ros Donald and Christian Hunt of The Carbon Brief debunk Boris Johnson's latest climate sceptic rantings.

By Ros Donald and Christian Hunt of The Carbon Brief

Mayor of London Boris Johnson bemused the world in the run up to the Olympics with a patriotic speech about table tennis’s purported ancestor ‘whiff-whaff’, an ancient game built around the idea of a good back and forth.

Johnson’s conception of climate science also seems to be based around the idea of a good back and forth – between scientists and sceptics.

He gave his latest thoughts on the subject for Telegraph readers today, as from his window in snowy Islington, he muses on the subject of snowy winters. He turns to the theories of climate sceptic meteorologist, Piers Corbyn, who believes far from warming, the globe might be heading for a “mini ice age”.

This isn’t the first time Johnson has touted this idea. In fact, any season appears to offer an opportunity to suggest we’re due an ice age. Just before the Olympics the £250,000-a-year Telegraph columnist was inspired to write another defence of Corbyn’s theory, this time after looking out of the window at the rain.

The gist of Corbyn’s theory was laid out yesterday by Johnson in a paragraph that does at least prove the mayor is a fan of recycling – it is taken almost verbatim from the earlier article.

He says:

“There are times in astronomical history when the Sun has been churning out more stuff – protons and electrons and what have you – than at other times. When the Sun has plenty of sunspots, he bathes the Earth in abundant rays. When the solar acne diminishes, it seems that the Earth gets colder. “No one contests that when the planet palpably cooled from 1645 to 1715 – the Maunder Minimum, which saw the freezing of the Thames – there was a diminution of solar activity. The same point is made about the so-called Dalton minimum, from 1790 to 1830. And it is the view of Piers Corbyn that we are now seeing exactly the same phenomenon today.”

We asked some climate scientists for their thoughts on the piece, and this argument in particular.

Joanna Haigh, a professor of atmospheric physics at Imperial College, specialises in studying the effect of the sun on climate.

She explained to us most scientists have moved on from looking out of the window to tell them what’s going on with the climate:

“I’m delighted that the mayor maintains his interest in weather and climate but he should be wary of drawing generalised conclusions from his observations. He suggests that the cold weather in London is due to declining solar activity – but actually the Sun is more active now than it has been since 2009, and about the same as it was in 2004 and 1998. “On longer timescales – decades to century – the sun may be very slowly declining in activity but this can’t explain year-to-year variations in UK winter weather. The mayor makes an interesting point about the weather during the Maunder Minimum in sunspots and, although the cooler weather then was largely confined to north-west Europe, that may quite likely have been influenced by the Sun. But at that time solar energetic output was considerably lower than it is today. “What we have is the lovely variability and uncertainty of British weather sitting on top of a long term global average warming due to greenhouse gas increases. This is not an issue of opinion but one of basic physics. We just don’t need to invoke mysterious effects of solar particles to understand long-term trends in global temperatures.”

Dr Peter Stott, who leads the Met Office’s climate monitoring and attribution unit, told us the idea the sun could override the effects of human activity on the climate doesn’t stack up:

“There is a strong scientific consensus that human-induced greenhouse gas emissions are the main cause of global warming over the last 50 years and it is misleading to the public that other theories, such as that most of the warming is caused by solar changes, carry equal weight. “In fact the fingerprint of human activity is very clearly seen in the observed pattern of temperature changes including warming in the troposphere (the lower atmosphere) and cooling in the stratosphere (the upper atmosphere above about 10km) and greater warming over land than ocean. Solar forcing on the other hand has not been increasing over the last three decades and an increasing solar contribution to global warming would have lead to warming of the stratosphere not cooling.”

Chris Rapley, professor of climate science at University College London, told us why Corbyn’s views are at odds with the broader scientific understanding of how the climate works:

“Climate science shows that the sun does have an influence on climate; this is not controversial. The planet responds to changes in the flux of energy that it intercepts from the Sun – known as the Total Solar Irradiance (TSI). What is in dispute is whether the sun has contributed to the energy imbalance (and associated energy accumulation) that the earth has experienced over the last half-century or so. “Climate scientists have concluded that the answer is no, based on the known ways in which the sun exerts its influence. “If anything, the sun (through a slightly lower TSI) has diminished the human-induced warming a little. But it may be that there are solar influences not recognised or understood. In this respect, Piers Corbyn should publish his insights so that they can be scrutinised and a judgement made about their credibility. If he has a genuine contribution to make, why would he not do so? The issue is, after all, rather important!”

Of course, BoJo is nothing if not entertaining – and a canny politician. We can’t imagine his latest column will do him any damage with the wing of the Conservative party that is less-than-keen on climate policies.

And the whole thing is done with an air of tongue-in-cheek – with Boris assuring us:

“I am not for a second saying that I am convinced Piers is right; and to all those scientists and environmentalists who will go wild with indignation on the publication of this article, I say, relax. I certainly support reducing CO2 by retrofitting homes and offices – not least since that reduces fuel bills. I want cleaner vehicles.”

Unfortunately, polling data shows a significant number of people are still confused about what’s causing climate change. Fringe scientific theories receiving more attention than they warrant from some parts of the media – and some columnists – probably doesn’t help.

Risking being wrong about the origins of whiff-whaff has limited consequences; a potential future prime minister who is easily led by fringe theories about the basics of climate change might give more pause.

This article was first published on The Carbon Brief.

See also:

• Delingpole debunked by Met Office – January 10th, 2013

As you’re here, we have something to ask you. What we do here to deliver real news is more important than ever. But there’s a problem: we need readers like you to chip in to help us survive. We deliver progressive, independent media, that challenges the right’s hateful rhetoric. Together we can find the stories that get lost.

We’re not bankrolled by billionaire donors, but rely on readers chipping in whatever they can afford to protect our independence. What we do isn’t free, and we run on a shoestring. Can you help by chipping in as little as £1 a week to help us survive? Whatever you can donate, we’re so grateful - and we will ensure your money goes as far as possible to deliver hard-hitting news.