Has global warming really stopped?

Mark Lynas responds to a controversial article on newstatesman.com which argued global warming has s

On 19 December the New Statesman website published an article which, judging by the 633 comments (and counting) received so far, must go down in history as possibly the most controversial ever. Not surprising really – it covered one of the most talked-about issues of our time: climate change. Penned by science writer David Whitehouse, it was guaranteed to get a big response: the article claimed that global warming has ‘stopped’.

As the New Statesman’s environmental correspondent, I have since been deluged with queries asking if this represents a change of heart by the magazine, which has to date published many editorials steadfastly supporting urgent action to reduce carbon emissions. Why bother doing that if global warming has ‘stopped’, and therefore might have little or nothing to do with greenhouse gas emissions, which are clearly rising?

I’ll deal with this editorial question later. First let’s ask whether Whitehouse is wholly or partially correct in his analysis. To quote:

"The fact is that the global temperature of 2007 is statistically the same as 2006 as well as every year since 2001. Global warming has, temporarily or permanently, ceased. Temperatures across the world are not increasing as they should according to the fundamental theory behind global warming – the greenhouse effect. Something else is happening and it is vital that we find out what or else we may spend hundreds of billions of pounds needlessly."

I’ll be blunt. Whitehouse got it wrong – completely wrong. The article is based on a very elementary error: a confusion between year-on-year variability and the long-term average. Although CO2 levels in the atmosphere are increasing each year, no-one ever argued that temperatures would do likewise. Why? Because the planet’s atmosphere is a chaotic system, which expresses a great deal of interannual variability due to the interplay of many complex and interconnected variables. Some years are warmer and cooler than others. 1998, for example, was a very warm year because an El Nino event in the Pacific released a lot of heat from the ocean. 2001, by contrast, was somewhat cooler, though still a long way above the long-term average. 1992 was particularly cool, because of the eruption of a large volcano in the Philippines called Mount Pinatubo.

‘Climate’ is defined by averaging out all this variability over a longer term period. So you won’t, by definition, see climate change from one year to the next - or even necessarily from one decade to the next. But look at the change in the average over the long term, and the trend is undeniable: the planet is getting hotter.

Look at the graph below, showing global temperatures over the last 25 years. These are NASA figures, using a global-mean temperature dataset known as GISSTEMP. (Other datasets are available, for example from the UK Met Office. These fluctuate slightly due to varying assumptions and methodology, but show nearly identical trends.) Now imagine you were setting out to write Whitehouse’s article at some point in the past. You could plausibly have written that global warming had ‘stopped’ between 1983 and 1985, between 1990 and 1995, and, if you take the anomalously warm 1998 as the base year, between 1998 and 2004. Note, however, the general direction of the red line over this quarter-century period. Average it out and the trend is clear: up.

Note also the blue lines, scattered like matchsticks across the graph. These, helpfully added by the scientists at RealClimate.org (from where this graph is copied), partly in response to the Whitehouse article, show 8-year trend lines – what the temperature trend is for every 8-year period covered in the graph.

You’ll notice that some of the lines, particularly in the earlier part of the period, point downwards. These are the periods when global warming ‘stopped’ for a whole 8 years (on average), in the flawed Whitehouse definition – although, as astute readers will have quickly spotted, the crucial thing is what year you start with. Start with a relatively warm year, and the average of the succeeding eight might trend downwards. In scientific parlance, this is called ‘cherry picking’, and explains how Whitehouse can assert that "since [1998] the global temperature has been flat" – although he is even wrong on this point of fact, because as the graph above shows, 2005 was warmer.

Note also how none of the 8-year trend lines point downwards in the last decade or so. This illustrates clearly how, far from having ‘stopped’, global warming has actually accelerated in more recent times. Hence the announcement by the World Meteorological Organisation on 13 December, as the Bali climate change meeting was underway, that the decade of 1998-2007 was the “warmest on record”. Whitehouse, and his fellow contrarians, are going to have to do a lot better than this if they want to disprove (or even dispute) the accepted theory of greenhouse warming.

The New Statesman’s position on climate change

Every qualified scientific body in the world, from the American Association for the Advancement of Science to the Royal Society, agrees unequivocally that global warming is both a reality, and caused by man-made greenhouse gas emissions. But this doesn’t make them right, of course. Science, in the best Popperian definition, is only tentatively correct, until someone comes along who can disprove the prevailing theory. This leads to a frequent source of confusion, one which is repeated in the Whitehouse article – that because we don’t know everything, therefore we know nothing, and therefore we should do nothing. Using that logic we would close down every hospital in the land. Yes, every scientific fact is falsifiable – but that doesn’t make it wrong. On the contrary, the fact that it can be challenged (and hasn’t been successfully) is what makes it right.

Bearing all this in mind, what should a magazine like the New Statesman do in its coverage of the climate change issue? Newspapers and magazines have a difficult job of trying, often with limited time and information, to sort out truth from fiction on a daily basis, and communicating this to the public – quite an awesome responsibility when you think about it. Sometimes even a viewpoint which is highly likely to be wrong gets published anyway, because it sparks a lively debate and is therefore interesting. A publication that kept to a monotonous party line on all of the day’s most controversial issues would be very boring indeed.

However, readers of my column will know that I give contrarians, or sceptics, or deniers (call them what you will) short shrift, and as a close follower of the scientific debate on this subject I can state without doubt that there is no dispute whatsoever within the expert community as to the reality or causes of manmade global warming. But even then, just because all the experts agree doesn’t make them right – it just makes them extremely unlikely to be wrong. That in turn means that if someone begs to disagree, they need to have some very strong grounds for doing so – not misreading a basic graph or advancing silly conspiracy theories about IPCC scientists receiving paycheques from the New World Order, as some of Whitehouse’s respondents do.

So, a mistaken article reached a flawed conclusion. Intentionally or not, readers were misled, and the good name of the New Statesman has been used all over the internet by climate contrarians seeking to support their entrenched positions. This is regrettable. Good journalism should never exclude legitimate voices from a debate of public interest, but it also needs to distinguish between carefully-checked fact and distorted misrepresentations in complex and divisive areas like this. The magazine’s editorial policy is unchanged: we want to see aggressive action to reduce carbon emissions, and support global calls for planetary temperatures to be stabilised at under two degrees above pre-industrial levels.

Yes, scientific uncertainties remain in every area of the debate. But consider how high the stakes are here. If the 99% of experts who support the mainstream position are right, then we have to take urgent action to reduce emissions or face some pretty catastrophic consequences. If the 99% are wrong, and the 1% right, we will be making some unnecessary efforts to shift away from fossil fuels, which in any case have lots of other drawbacks and will soon run out. I’d hate to offend anyone here, but that’s what I’d call a no-brainer.

Mark Lynas has is an environmental activist and a climate change specialist. His books on the subject include High Tide: News from a warming world and Six Degree: Our future on a hotter planet.
Show Hide image

Sadiq Khan interview: “London can’t have somebody stuck in the 1980s or 1990s”

The Labour London mayoral candidate on why he is the "modern" figure the city needs, Tessa Jowell's "control freakery", and Islamist extremism. 

"You’ve brought the sun out!" says Sadiq Khan as he greets me on the rooftop of Boxpark in Shoreditch, east London. I quickly slake my thirst with the water provided by his aide but Khan does not. The Tooting MP and devout Muslim has begun fasting for Ramadan, abstaining from food and drink for 19 hours a day.

If Khan, who is 44, is low on energy it does not show. The former shadow justice secretary speaks fluently and passionately about his bid to become Labour’s London mayoral candidate and his vision for the capital.

He reveals his intention, if he wins, to establish the Bazalgette Award, named in honour of Joseph Bazalgette, the Victorian creator of the city's sewer network. "We know London's got huge problems in relation to infrastructure, in relation to environmental concerns, in relation to simple things like not having air conditioning on the tube ... 150 years ago London also had problems and people with foresight designed sewers, for example, fit not just for the 19th century but still working in the 21st century ...

"What it will be is an award for innovation, for solutions, so I’ll be saying to Londoners and those around the world, 'Look, here are some of our problems, if you come up with a solution not only will you get an award, not only will you get reward money, we’ll spend money to do feasibility studies, we’ll spend money to consult, we’ll spend money to make sure that your ideas bear fruit.'" 

He also vows to introduce "Skills for Londoners" - a partnership between business, the mayoralty and educational institutions, modelled on programmes such as New York mayor Bill de Blasio’s Jobs for New Yorkers and Tech Talent Pipeline. Khan promises to "train Londoners for the skills of tomorrow: tech, creative industries, low carbon, manufacturing". He notes that Tech City, where we are sitting, "now rivals the finance sector in relation to what it contributes to our country” and asks “What about the next Tech City? I’m going to be the mayor who thinks about tomorrow’s jobs."

Khan continues: "London’s a modern city and it needs a modern mayor ... What I think we can’t have as a city is somebody stuck in the 1980s or 1990s, we need somebody who’s thinking about the 2020s." His words are a coded attack on rival candidates Diane Abbott, the MP for Hackney North and Stoke Newington since 1987, and Tessa Jowell, who served in Tony Blair’s cabinet. "Tessa and Diane have been in politics since I was at school and I’ve got a huge amount of respect for them, it’s on their shoulders that many of us stand,” he tells me. “I don’t think [Jowell’s] got the answers for the 2020s, the future business, we’re a modern city, we’re young, we’re diverse." I ask if he is suggesting that Jowell, who is 67, is simply too old to be mayor. "For me, it’s not about age, it’s about asking the right questions, it’s about understanding tomorrow’s problems," the 44-year-old replies.

It is the former Olympics minister who is Khan’s main opponent in the Labour nomination contest. A recent YouGov poll found that he had narrowed her lead among party supporters (who will select the candidate in a primary) from 15 points to just three and several bookmakers have installed him as the favourite. But Jowell’s allies eagerly cite a survey putting her 14 points ahead of the most likely Conservative candidate, Zac Goldsmith (57-43), with Khan merely tied (50-50). "Two weeks after launching my campaign I’m neck-and-neck," he says when I reference the poll. "I’m confident that over the next few weeks and months I’ll show that I’m not only the only candidate that can win, I’m winning for a purpose."

One of Jowell’s biggest hindrances is her association with Tony Blair, who she once declared she would “jump in front of a bus to save”. Jowell recently denied making the remark only to be contradicted by a 2009 video in which she affirmed her pledge. When I mention the imbroglio to Khan he laughs and says “It’s no secret how close Tessa and Tony Blair are. It’s for Tessa to answer that question. I was surprised when I read the tweet in which she said that she hadn’t said that. It’s for Tessa to explain her local difficulty.” He goes on to accuse her of New Labour "control freakery" - "When your supporters turn up to a hustings to cheer you on, that’s just so 1990s. [In fact, Ed Miliband's supporters did the same for him at the 2010 New Statesman Labour leadership hustings.] The idea you have people turning up to a CLP [Constituency Labour Party] meeting, organising so other candidates are nominated, that’s just so 1990s. My criticism is not her age, it’s the way that sort of politics is done, I think it’s past its sell-by date." 

But what does Khan say to those who brand him "the union candidate" and "the Ed Miliband candidate"? "The fact that other people who are running to be mayor are being negative speaks volumes for them," he says. "I’m really proud that nurses, bus drivers and lollipop ladies are supporting me in my candidature to be mayor of London," he adds in reference to his trade union endorsements. "I’m also really proud, by the way, that chief executives, business owners and entrepreneurs are supporting me as well. I’m really proud that Muslims, Sikhs, Hindus, Jews and Christians are supporting me."

He says that Miliband, who appointed him as shadow London minister in 2013 and whose leadership campaign he managed, should remain an MP for the next five years.

"One of the first things I said to Ed after the results was what you cannot do is step down from parliament, you’ve got a lot to offer. He’s 45-years-old, he’s got a huge amount to offer and it’s really important that he does so." But he adds: "The important thing for me though is I’m my own man, I’m Sadiq Khan. Ed and others will offer ideas, some of them I’ll take on, some of them I won’t and I’ve got to be allowed to be my own man. What's been great about the last few weeks is I’ve been able to get people to know me."

Sadiq Khan was the first British Asian and the first Muslim to attend cabinet. He speaks with justifiable pride of his background. "As the son of a bus driver, as somebody who’s the son of immigrants, as somebody who was raised on a council estate, as somebody who slept on a bunk bed when he was 24, I get aspiration," he says in reference to the political word du jour. He criticises those in Labour who "give the impression that only those who shop in Waitrose have aspiration".

He reflects on how London has changed since his father arrived as an immigrant from Pakistan. "When my dad first came here there were signs up literally saying 'No blacks, no Irish, no dogs.' Thirty years on, my dad would have to pinch himself and my mum still does, that their son is on the cusp of being elected as mayor. And their pride isn’t in me, their pride is in London, their pride is in Tooting for electing their son MP, their pride is in London for being on the cusp of choosing their son to be the mayor of this great city."

On the day that I meet Khan, David Cameron has argued that some Muslim communities have "quietly condoned" Islamist extremism. "You’ve got to be very careful with language, you don’t want to inadvertently help others do the job for them," says Khan, adding that he believes "Cameron’s intentions are noble". His message to "anybody thinking about going to Syria or Iraq" is that "you can do far more good for the people of Syria and Iraq, getting involved in a mainstream charity, giving money to good causes, helping us try and influence foreign policy, helping us reach a resolution to the problems of the Middle East, you can do far more as an active citizen here than going to Syria and Iraq, especially if you’re a woman."

He continues: "I say this as the father of two daughters who’s worried about what goes on the internet. It is the case that in many Muslim majority countries women don’t have equality ... I say this to my daughter: you’ve got far more chance of fulfilling your potential here than in Syria and Iraq. That’s why it’s so important for someone like me to be the mayor of this great city, to send a message, to be a beacon."

Khan has announced policies including a new "London living rent", a four-year freeze on Tube and bus fares, and opposition to a third runway at Heathrow. He supports far greater devolution to the capital. "I want to be in charge of skills, I want to be in charge of back-to-work, Londoners should be much more in charge of housing. I think Londoners should be in charge of infrastructure, I think Londoners should be in charge of the NHS in London, we’re already in charge of public health. The more power London’s got over its own destiny, the better we’ll do and the better the country will do as well." 

When I mention that another rival candidate, David Lammy, has accused him of opportunism over his stance on Heathrow ("If the facts change, I change my mind," Khan tells me), he replies: "David Lammy, Diane Abbott and Tessa Jowell all may be saying beastly things about me, I take that as a badge of pride. If they’re rattled that’s for them to be rattled. I’m really not taking an interest in what they’re saying about me that’s negative. I want to have a positive campaign, I want to have an open campaign, I want to have a campaign that’s very much fraternal." 

And should he fall short, will he seek to return to the shadow cabinet? "I’m an optimist. I’m in this to win this and I’m confident that I’ll be selected as Labour’s candidate and I’m confident that I’ll be mayor of London after 5 May."

George Eaton is political editor of the New Statesman.

This article first appeared in the 26 June 2015 issue of the New Statesman, Bush v Clinton 2