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.
Miles Cole for New Statesman.
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The pugilist: Sadiq Khan’s quest to become mayor of London

Can the Tooting MP complete the journey from council home to City Hall? 

One recent morning, Sadiq Khan entered the ring at Earlsfield Amateur Boxing Club in Wandsworth, south London. He ­began sparring with one of the regulars: ducking, weaving, throwing jabs. Khan learned to box as a boy, partly for self-defence; two of his brothers are coaches at the volunteer-run academy near Tooting, the constituency he has represented since 2005. Among those pictured on the wall is Frank Bruno, the club’s most famous son.

Khan had invited me to join him, and soon after I arrive at 10am, Pop, the youngest of his seven siblings, inducts me in the ring and we begin 90 minutes of training. “Boxing isn’t fighting,” Khan told me when I interviewed him two days earlier. “It’s a classic mistake people make – boxing is a sport. The skills you learn are life skills: being magnanimous, what to eat, how to keep fit, how to look out for each other. The first thing you learn in boxing is defence – you’ve got to defend yourself . . . We all boxed [in my family] and that gives you confidence if you get into bother on the street.”

The only one of his brothers not to compete at amateur level, Khan preferred football and cricket (he had trials for Surrey). But he moves with an agility seldom associated with MPs – many of whom are more likely to be found in the Palace of Westminster’s bars than its gym. As a devout Muslim, Khan does not drink, and in 2014 he ran the London Marathon.

During our warm-down we pass a road on which his father drove the number 44 bus. A few minutes away is the council estate where Khan grew up. He doubts that bus drivers today could afford to live in the area, and speaks with sadness at how gentrification has frayed the bonds of community. It was the fear that working-class Londoners were being denied the opportunities ­afforded to his family that partly inspired his candidacy for mayor of London.

***

In eight weeks, on 5 May, Sadiq Khan will compete in the UK’s biggest bout of all. With the exception of the French president, no European politician has a larger personal mandate than the mayor of London. The city's leader controls a £16bn budget and housing, planning and transport policy. If the government lives up to its devolutionary rhetoric, the next incumbent will acquire still greater powers.

For the past eight years, London has been led by Boris Johnson, who twice defeated his Labour predecessor, Ken Livingstone. But Khan is predicted to win back City Hall for Labour. Zac Goldsmith, the Tory MP for Richmond Park, whose billionaire father founded the Eurosceptic Referendum Party, was the candidate that many in Labour feared: telegenic, green (he edited the Ecologist magazine) and socially liberal. The Tories’ hope was that, like Johnson, Goldsmith would attract non-Conservative voters. Yet in a city that leans ever more towards Labour – the party won 45 of its 73 seats in last year’s general election – few believe he can emulate his predecessor. Fellow Tories have criticised his campaign as “low-energy”. The most recent poll, published by Opinium on 8 March, gave Khan a 10-point lead in the final round.

“I’m the least complacent person you’ll find but I’m quietly confident,” he told me.

Khan, colleagues often say, is “a winner”. At the 2010 general election, he defended his Tooting seat from an aggressive and well-funded Conservative challenge. In the same year, he managed Ed Miliband’s leadership campaign, masterminding the defeat of Miliband’s elder brother, David. In the 2014 local elections, after Miliband rewarded him with the post of shadow minister for London, Khan achieved Labour’s best result in the capital since 1971. At last year’s general election, on an otherwise morose night, the party gained seven seats in London, its strongest performance since 2001.

When Khan announced in May last year that he would stand to be Labour’s mayoral candidate, many expected him to be defeated by Tessa Jowell, the popular former Olympics minister. It was not an assessment that Khan ever shared. As David Lammy, who finished fourth in the selection contest, told me: “I remember Sadiq sitting in his office – it would have been six months before the campaign got going. He looked me in the eye and said, ‘You know, I am going to do this.’ He was steely about it and very clear in his own mind.”

Khan’s team emphasised an ­elementary but overlooked truth: it was Labour Party members and supporters who would choose the candidate. The party’s leftwards trajectory gave him the advantage. Unlike Jowell, an unashamed Blairite, Khan opposed the Iraq War, a totemic issue for activists. He worked hard to win the endorsements of Ken Livingstone, the Unite, GMB and CWU trade unions and his fellow London MPs. Khan’s nomination – if not support – of Jeremy Corbyn for the Labour leadership and his opposition to the Welfare Reform and Work Bill gave him further credibility among the party’s selectorate. His policies included a London Living Rent (based on a third of average local income) and a four-year freeze on Tube and bus fares.

While Jowell and other candidates attempted to appeal to existing party members, Khan recruited new ones. Over the four-month campaign, he made more than 200 visits to workplaces, community centres, churches, temples, mosques and shopping malls. “The thing that should never be underestimated with Sadiq is his ability to campaign,” Lammy told me. “He’s a bit like a terrier; when he gets his teeth into something he’s not going to let it go.” Jowell simply told me that Khan was a “formidable campaigner” and that “all the signs are that he’s going to win”.

When the selection result was announced on 11 September 2015, with Khan beating Jowell 59-41 in the final round of voting, many were stunned by his landslide victory. But not him. “I never thought it was going to be a close race,” he told me just after the result was announced at the Royal Festival Hall. “I always knew – irrespective of what respectable London newspapers may write and who they’re going to endorse – when it comes to voters seeing what the candidates stand for and what their vision is, I’d win.”

No one I spoke to doubted Khan’s political skill, but some questioned his integrity. “He has got a tendency to want it so much that he slightly overeggs it,” a senior Labour MP told me. “Some of that mud will get thrown at him: that he changes his position, that he is politically expedient – and that then goes to trust. What does he really stand for?”

Having nominated Corbyn for the leadership, Khan was derided for sharply rebuking the new Labour leader in a Mail on Sunday interview on 20 September. He warned that Corbyn’s meetings with Hamas and Hezbollah reinforced Labour’s “anti-Jewish” image, criticised him for failing to sing the national anthem (“He was very unwise. You are trying to be the British prime minister”) and vowed to “work closely with a Tory government if it is in London’s interest”.

Such comments, opponents suggested, would never have been made during the selection contest for the mayoral candidacy – when he needed the Corbynites. But he insists there was no inconsistency. “I was quite clear when I nominated Jeremy that I wasn’t going to vote for him [Khan endorsed Andy Burnham]. Look on my Twitter timeline. And, George, in the selection process I was asked whether I would serve in his shadow cabinet, if I wasn’t successful, and I said no – because we come from different parts of the party. We believe in different things.”

Without the help of Khan and other non-supporters, Corbyn would not have made the ballot. Khan insisted that he had no regrets. “Jeremy Corbyn, to give him some credit, won among Labour Party members, among Labour Party supporters and among trade union supporters . . . You can have an analysis of why the other candidates failed to inspire, enthuse and engage with the membership, whereas Jeremy did, and that’s a conversation for them to have.”

He rejected the suggestion that his victory was a by-product of Corbynism. Were that the case, he said, one would have expected Diane Abbott or Christian Wolmar (both of whom voted for the eventual leader) to win. “The reason why that didn’t happen was because in my campaign I managed to enthuse, inspire and engage the selectorate. My mandate is similar to Jeremy’s, almost 60 per cent ... We were fizzing with energy, we had ideas and we won.”

His attempts to distance himself from the Labour leader have led the Tories to label him “Corbyn’s man”. At a Goldsmith rally on 26 January, David Cameron warned voters that they would be “lab rats in the first Corbyn economic experiment in public life” if Khan won.

However, in tacit acknowledgement of the risk posed by Corbyn’s unpopularity, Khan does not plan to appear in public with him in the lead-up to May (to the consternation of Corbyn’s allies). The leader’s role will be limited to voter mobilisation: leafleting, fundraising and phone banking. Yet Corbyn has more cause than most to hope that Khan is successful. Labour is forecast to become the first opposition since 1982 to lose council seats in a non-general-election year; retaking the mayoralty would provide crucial consolation.

Khan is also avoiding campaign appearances with Livingstone and has ruled out giving him a job if he wins. “If you’re running for mayor, your job is to represent London – you’ve got to stand up for London,” Livingstone said of Khan. “You often have to disagree with a Labour government, as I had to. It’s a campaign between Zac and Sadiq; it’s not a rerun of me and Boris. We should keep out of it.”

***

The day after Corbyn made the Labour leadership ballot on 15 June last year, Khan was again accused of expediency when he announced that he opposed a third runway at  Heathrow Airport in favour of Gatwick. “Sadiq was for Heathrow expansion in 2008; he was for it when he was transport minister in 2009. Zac Goldsmith has announced he is running [the Tory candidate is a long-standing opponent], and suddenly he’s against it,” Lammy told a mayoral hustings. But Khan denied that his stance was born of opportunism. “It was born out of the facts. Unlike Zac Goldsmith, I accept the case for an increase in flight capacity in this part of the country. I think the case has been made for jobs and growth.

“But in the last full year for which there’s data almost 10,000 Londoners died because of air pollution. There are children in parts of London whose lungs are underdeveloped. The UK Supreme Court last April held that the air-quality directive had been breached. So air is a killer – it makes you sick and it’s illegal. In those circumstances, you can’t say yes to a new runway at Heathrow.”

At Gatwick, he added, far fewer people were affected by air and noise pollution.

The Tories have recently levelled a far graver charge than that of Corbynism or opportunism: that Khan is a friend of Islamist extremists. On 7 February the Sunday Times reported that Khan had attended four meetings of the group Stop Political Terror (while campaigning against the US-UK extradition treaty), which had the support of Anwar al-Awlaki, the late al-Qaeda cleric. On 12 February, across two pages, the London Evening Standard noted that Khan’s former brother-in-law, Makbool Javaid, had attended events organised by the extremist group al-Muhajiroun in the 1990s (the pair have not spoken for a decade). Four days later, MailOnline reported that Khan had given a speech at the 2008 Global Peace and Unity festival while the “black flag of jihad” was flying.

Nick Timothy, a former chief of staff to the Home Secretary, Theresa May, told me: “Khan wants to be the mayor for millions of Londoners at a time when the terror threat is very real. An attack could happen at any time and he would have to respond and unite the city in those circumstances – he will be responsible for policing and community relations. He’s campaigned against the role of the police and allowed himself to share platforms with people who very definitely have the wrong kind of views. It’s not very good judgement if he wants to be the mayor of a city like London.”

Such comments frustrate Khan. “People who understand politics understand what happens at these things,” he said. “What happened was very simple.

“Many MPs from all parties, including Boris Johnson and Zac Goldsmith himself, had objections to the US-UK extradition treaty . . . Now, often when there are meetings happening about a cause, what happens is you’re very busy; the meeting may have been taking place for two, three, four hours; you’re doing other stuff. You go along, you take the stage, you do your spiel, you speak and more often than not just leave to do your next event.

“Often you’ve got no idea who was speaking before you, who’s speaking after you. Nobody could honestly, hand on heart, think I agree with the sort of views spouted by other people who spoke at the same meetings: that’s not the way it worked.

“I’ve been quite clear in my views in relation to extremism and radicalisation. I’ve been quite clear in my views in relation to people who claim to follow the same faith as me but have views that are abhorrent.”

He added: “So, what are you implying by your nudge-nudge and your wink-wink? What are you saying either about me or about the one million Londoners of Islamic faith? I get people approaching me all the time who are Muslim who say, ‘If they’re doing this to you, what chance have I got?’ or, ‘You’re encouraging us to get ­involved in mainstream politics yet this is how you’re treated’ or, ‘If they’re digging around, as they’ve been for months, about your extended family – about who used to be related to you, or whatever – what chance have we got?’”

He spoke of his dismay that Goldsmith, who some believed would shun such tactics, had pursued this path. “Those advising Zac to do this sort of stuff, it’s foolish advice. I thought Zac was bigger than this.”

Khan has received death threats from extremists for his involvement in democratic politics and, more recently, for supporting equal marriage. Friends say that despite the political and physical risks posed by taking this stance, he never hesitated. As a former human rights lawyer and champion of civil liberties (he chaired Liberty for three years), it was an automatic choice.

In a speech to the Parliamentary Press Gallery in November, a week after the Paris terror attacks, Khan spoke of how “successive governments had tolerated segregation in British society” and had allowed “the conditions that permit extremism to continue unchecked”.

He warned: “We’ve protected people’s right to live their cultural life at the expense of creating a common life. Too many British Muslims grow up without really knowing anyone from a different background, without understanding or empathising with the lives and beliefs of others.”

None of this has prevented his rivals making the claim that he is a friend of extremists and, by implication, one himself. But unlike Livingstone, who responded vociferously to accusations of anti-Semitism, Khan has maintained his composure.

“I’ve watched him go through this extremism row two or three times quite closely,” an MP told me. “He’s extraordinarily calm under that level of pressure. He draws on a well of inner stability that is really impressive. Tony Blair could obviously do it in spades but there are not that many senior politicians who can do it.”

***

Sadiq Aman Khan was born on 8 October 1970 at St George’s Hospital in Tooting. His grandparents emigrated from India to Pakistan following Partition; his parents emigrated from Pakistan to London shortly before his birth. Khan was the fifth of eight children (he has six brothers and one sister). His late father, Amanullah, was a bus driver for more than 25 years; his mother, Sehrun, was a seamstress.

Khan attributes his work ethic to his upbringing. “My dad worked all the hours that God sent as a bus driver. If he got overtime he’d take it. My mum not only raised eight children but was sewing clothes in the house while raising us, while cooking.

“I was surrounded by my mum and dad working all the time, so as soon as I could get a job, I got a job. I got a paper round, a Saturday job – some summers I laboured on a building site.”

He was taught to support those in need. “My mum and dad would send money to their relatives back in Pakistan. My mum still does, because we’re blessed being in this  country.”

The family grew up on the Henry Prince council estate in Earlsfield, where Khan and his seven siblings squeezed into a three-bedroom home. He did not travel abroad until he was 23 and slept in a bunkbed until he was 24. He attended the Ernest Bevin comprehensive school (named after the former Labour foreign secretary), which Independent editor Amol Rajan described as “the dreaded second choice ... the staple of local news reports about drugs, gangs and local hoodlums.” I asked Khan if this Tarantino-esque description was accurate.

“Listen, I’m very careful of speaking about certain things because it gives the impression ... Look, it’s still a school and children still go there, you don’t want to tarnish the reputation of the school. It was a great school, it fulfilled my potential. I’m not one of these people who moans that I could have been this if I’d gone to this school. It was a great school, the teachers worked their socks off.” He added: “It was a tough school, though, you had to be streetwise, you had to look after yourself.”

Racism was a feature of the family’s life. Bus passengers referred to his bearded father as “Paki Santa” and assaulted him. Such insults sometimes prompted Khan to use his boxing skills. “We went down on the floor hitting each other,” he told the Mail on Sunday of one fight. “He didn’t call me the ‘P-word’ again.”

Khan and his brothers also encountered racism on the football terraces. “I experienced Wimbledon, my brothers experienced Chelsea,” he told me. “At Stamford Bridge there’s a place called ‘the shed’. The NF [National Front] would sell newspapers and wear boots and the green bomber jackets and chase people like my brothers away, call them names.

“I didn’t support Chelsea because I didn’t want to support a club that had racist fans. Plough Lane was down the road ... I remember going to watch Wimbledon vs Spurs, it was an FA Cup game. Although I was a Wimbledon fan, at the Wimbledon end, after the game I was racially abused by fans using the Y-word and the P-word.

"I didn’t go back to Plough Lane.”

He then spoke movingly of the extent to which London had progressed. “My daughters [Anisah and Ammarah] are 16 and 14 and they’ve basically grown up in the same area that I grew up in and my wife grew up in. They’ve never been called the P-word – they’ve never been the victim of overt racial abuse. That shows the progress we’ve made.”

At school, a teacher told Khan, who studied biology, chemistry and maths at A-level, “You’re always arguing. Why don’t you be a lawyer, rather than a dentist?” It was this, as well as LA Law on television, that inspired him to join the Bar. He studied at the University of North London (now London Metropolitan), where he became a visiting lecturer, and took his finals at the Guildford College of Law. Having joined Labour at the age of 15, he was elected as a councillor in Wandsworth in 1994. That same year, he married Saadiya Ahmed, a fellow solicitor.

Khan told me he made a conscious decision to specialise in human rights law (“acting for the underdog”), rather than corporate law. “It wasn’t work for the sake of becoming a millionaire. It was working hard and giving something back.”

He became a trainee solicitor in 1994 at Christian Fisher under the renowned human rights lawyer Louise Christian. Three years later, he was made a partner – a precocious achievement for someone of his age and background. In 2004 he left the company, which had been renamed Christian Khan, to become the Labour candidate for Tooting. Khan and his former partner, who was aggrieved by his sudden departure, have not spoken since.

As a human rights lawyer, he acted for what he recently described as “unsavoury individuals”, such as Louis Farrakhan, the leader of the Nation of Islam, and Babar ­Ahmad, who pleaded guilty in the US in 2013 to “providing material support to terrorism”. Ahmad, whose extradition was opposed by Khan and other MPs (including Goldsmith), was a childhood friend. Khan’s opponents have sought to exploit this.

“We never went to each other’s houses. We weren’t close friends but we knew each other growing up – we’d see each other at mosques,” Khan told me. “When you see people at the mosque you don’t discuss politics and stuff. It’s, ‘How you doing? How’s things?’ You may play cricket together, as most kids do at the park and stuff. I can’t remember having an argument about his views in detail. What I do know is that when he was arrested it was a big deal because he was the victim of police misconduct. He brought a claim and won damages in relation to how he was treated – he suffered serious injuries.” Khan has seen Ahmad twice since he was released from prison in the US: at a funeral at Balham Mosque and on the Tube with his lawyer.

In 2005, Khan was elected as the MP for Tooting, his lifelong home. He was praised by former shadow business secretary Chuka Umunna, who represents neighbouring Streatham, as a constituency champion. "In spite of the fact that he's had a national role he was never seen to have taken his eye off the ball of the local situation," he told me. 

Six months after entering parliament, Khan rebelled over Tony Blair’s attempt to introduce 90-day detention for terror suspects, the first of several clashes with the then prime minister. In 2006 he signed an open letter warning that the government’s foreign policy provided “ammunition to extremists”. On the tenth anniversary of the 7 July 2005 London bombings, he spoke of how Blair had “called the four MPs of Islamic faith in to No 10 and sat us round a table and said – to Mohammad Sarwar, Khalid Mahmood, Shahid Malik and myself – it was our responsibility.

“I said: ‘No it’s not. Why have you called us in? I don’t blame you for the Ku Klux Klan. Why are you blaming me for the four bombers on 7/7?’” (This account is contested by Mahmood and Malik, who accused Khan of “self-serving revisionism”.)

“They’re allowed to recollect things how they like,” he told me. “I’m quite clear in my recollection . . . It reinforces my view that we’ve got to defeat radicalisation and extremism by all of us working on this – this isn’t a uniquely Muslim problem. There’s a great saying, which is, ‘It takes a village to raise a child.’ Similarly, it will take a village to defeat terrorism and extremism.”

In Gordon Brown’s 2008 reshuffle, Khan was appointed communities minister, becoming the second Muslim to serve in government. The following year he was made transport minister: the first Muslim to attend cabinet and become a privy counsellor. “The palace called me and said, ‘What type of Bible do you want to swear on?’ When I said the Quran, they said, ‘We haven’t got one.’ So I took one with me.”

Of his faith, he told me: “It’s part of who I am – that’s the best way of describing it, because I’ve been asked this a lot. We all have multiple identities: I’m a Londoner, I’m British, I’m English, I’m of Asian origin, of Pakistani heritage, I’m a dad, I’m a husband, I’m a long-suffering Liverpool fan, I’m Labour, I’m Fabian and I’m Muslim.”

I asked him how he felt when an LBC/YouGov poll was published showing that 31 per cent of Londoners would be “uncomfortable” with a Muslim mayor. “That was during the selection campaign. When I saw it I was thoroughly depressed.

“When you’re the candidate in a campaign, you’ve got to be strong; you’re the leader. I went to the campaign – we’ve got lots of volunteers – three of my volunteers of Islamic faith were devastated. Two of them were crying. They just didn’t want to carry on because they were devastated that the impression was given that three out of ten Londoners are somehow Islamophobes.

“That’s not what the survey was about. With surveys, with polls, it’s how you ask the question. If I ask you the question, ‘Wouldn’t it be great if the mayor of London was of Islamic faith?’, what sort of message would that send? It elicits a very different answer to, ‘How comfortable are you with the mayor of London being a Muslim?’ And so I’ve spoken to people at LBC who on reflection realised that the question maybe shouldn’t have been asked, or at least asked in a different way.

“You can slice and dice it whichever way you want, this is a great, great city. There is no other city I’d rather raise my daughters in. I’ve got cousins in Pakistan, ethnic majority and religious majority, and they say to me they couldn’t achieve in Pakistan what I’ve achieved here.

***

For some politicians, campaigning is mere business; for Khan it is a pleasure. I joined him in east London as he visited start-ups hosted by the Bootstrap Company in Dalston: a film-maker, a bakery, a dressmaker. “Are you making a profit yet?” he asked. At a time when his party is increasingly perceived as “anti-business”, Khan takes every opportunity to present himself as a friend of enterprise. He has been aided by Goldsmith’s decision to support Brexit.

“We’re a city where literally more than 500,000 jobs are directly dependent on us being a member of the EU,” he said. “We’re a city where 60 per cent of the world’s companies choose their headquarters. Forty-three per cent of London’s exports go to the European Union. In those circumstances, if you want to be a good mayor, how can you be in favour of leaving?”

Goldsmith has argued that a Conservative mayor will invariably get a better deal from the government, a notion that Khan dismisses. “To give the current government their due, they do business with a Scottish Parliament, which is not Tory . . . they do deals with the Welsh Assembly, which is not Tory. They’ve given greater devolution to Greater Manchester, which is not Tory and probably never will be.

“I actually get on with George Osborne and other members of the government. Many of them sponsored me when I did the marathon. I think I’m friends with some of them.” Osborne, a fellow Londoner, personally congratulated Khan when he won the mayoral nomination.

Khan’s name is often mentioned alongside that of Sajid Javid, the business secretary and fellow bus driver’s son (“I’m the son of a bus driver. I used to love that line ... then Sajid fucking Javid came along,” Khan quipped during his press gallery appearance). “I saw him the other night, actually,” he said. “I think one of the great things about politics now is if you’re an ethnic minority the sole party for you to choose isn’t the Labour Party. That’s fantastic, I think, it’s really encouraging that both mainstream parties have embraced the importance of reflecting society.”

During his time in the shadow cabinet, Khan was one of Ed Miliband’s closest allies and a tribune of the soft left. But he told me that he no longer supports signature policies such as a 50 per cent income-tax rate or a “mansion tax”.

“It’s really important to understand that we had a manifesto, which we fought the 2015 election on, and we lost – we lost badly for the second time in a row.

“In the Eighties when we were losing elections, members of my party had a phrase, which I think was wrong, which is ‘no compromise with the electorate’. The electorate are always right.”

In his book If Mayors Ruled the World, Benjamin Barber writes that “a preference for pragmatism and problem-solving over ideology” is a feature of successful city leaders. It is a model that Khan – like Ken Livingstone before him, a socialist who forged an alliance with big business – has embraced.

If Sadiq Khan wins the race to lead London, he will capture a prize that increasingly eludes Labour outside the city: elected office. The election of a British Muslim mayor would be an event of international significance, and a symbol of London’s cosmopolitanism. “I’m fed up of losing. I don’t believe in heroic failure,” he told me. “I’ve got the policies, I’ve got the principle. We need the power to improve London.”

George Eaton is political editor of the New Statesman.

This article first appeared in the 10 March 2016 issue of the New Statesman, American Psycho