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.
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Puffins in peril

Britain’s best-loved seabird is vulnerable to global extinction.

The boatmen helped us scramble ashore and soon there were 50 people wandering on an uninhab­ited slab of sea-battered dolerite called Staple Island. It is one of the National Trust-owned Farne Islands in Northumberland and among England’s most spectacular wildlife locations. There are 100,000 pairs of breeding seabirds here and they were everywhere: at our feet, overhead, across every rock face. The stench of guano was overwhelming.

While the birds seemed to be boundless, the human beings converged on the grassy knoll where the local star attraction resides. It’s the creature that adorns the boat company’s publicity and is emblazoned on the National Trust’s website for the island, the bird that possesses what the poet Norman MacCaig called the “mad, clever clown’s beak”: the pint-sized, parrot-faced puffin.

The British love for this creature is so intense that it is, in essence, the robin redbreast of the sea. Nearly all of its breeding colonies around our coast are tourist attractions. Just across the water, along the shore from Staple Island, is the town of Amble, which holds an annual festival devoted to the puffin. From Lundy in Devon and Skomer in Pembrokeshire to the Isle of May off the Fife coast, or Fair Isle in the Shetlands, trips to puffin colonies are frequent, sometimes daily, events.

“Every tourist shop on these islands sells puffin merchandise – knitwear patterns, tumblers, carvings, coasters, cuddly toys, clothes and, of course, puffin hats,” Helen Moncrieff, the area manager in Shetland for the Royal Society for the Protection of Birds (RSPB), told me.

While the love affair is unquestionable, what seems in doubt is our ability to help the bird now that it is in trouble. Fair Isle once supported a puffin colony of 20,000 birds. In less than three decades, that number has halved. Similar declines have been reported at Britain’s most important puffin site on St Kilda, Scotland, where millions are said to have bred. Now there are fewer than 130,000 pairs, half the total recorded as recently as the 1970s.

The national picture is alarming but the news from elsewhere is even worse. Continental Europe holds more than 90 per cent – five million pairs – of the global total of Atlantic puffins but they are shared primarily between three countries: Denmark (the Faroe Islands), Iceland and Norway. Across this subarctic region, losses have been estimated at 33 per cent since 1979, when monitoring began. But the most striking figure comes from a colony on Røst, Norway, where there has been a fall over this period from nearly 1.5 million pairs to 285,000.

The Westman Islands off the south coast of Iceland hold a substantial proportion of the country’s puffins. Since 2005, breeding success there has been almost nil, and a similar failure has recurred on the Faroe Islands for more than a decade. In both places, where hunting puffins was once a staple of cultural life, catchers today have initiated a self-imposed moratorium.

Puffins are long-lived species and a life­span of between 20 and 30 years is not unusual, yet Euan Dunn, principal marine adviser to the RSPB, explains the implications of persistent breeding failure. “Puffins on Shetland or the Westmans may go on attempting to breed for years, even decades, but eventually all those old adult birds will die off and, if they haven’t reproduced, then the numbers will start to plunge.”

BirdLife International, a conservation network that classifies the status of birds worldwide, has reached the same conclusion. It judges that the Atlantic puffin is likely to decline by between 50 and 79 per cent by 2065. The nation’s most beloved seabird has been declared a species that is vulnerable to global extinction.

To unpick the story of puffin losses, marine ecologists have examined the bird’s oceanic ecosystem and looked particularly at changes in the status of a cold-water zooplankton called Calanus finmarchicus. This seemingly insignificant, shrimp-like organism plays a crucial role in North Atlantic biodiversity and has experienced a huge decline as sea temperatures have risen steadily since the 1980s. While the decline of the finmarchicus coincided with swelling numbers of a close relative, this other zooplankton species is less abundant and nutritious.

As the finmarchicus has suffered, so, too, has one of its main predators, the lesser sand eel. And it is this formerly superabundant fish that is the staple food of puffins in many areas of the Atlantic. At the root of the disruption to marine life are the hydra-headed effects of climate change.

Though no one disputes that an important shift is under way in the sea areas of northern Britain and beyond, not everyone agrees that the present puffin situation is a crisis. A leading British expert, Mike Harris, thinks it is premature to designate the bird an endangered species. There are still millions of puffins and, he says, “We need numbers to plummet before we even start to assume that things are terminal.”

Similarly, Bergur Olsen, one of the foremost biologists studying puffins in the Faroe Islands, believes that the talk of extinction is over the top. “The food situation may change and puffins may well adapt to new prey, and then their numbers will stabilise and perhaps increase,” he says.

***

On Staple Island, the extinction designation does appear bizarre. The Farne Island puffin population has increased by 8 per cent since 2008 and there are now 40,000 pairs. This success mirrors a wider stability among puffin colonies of the North and Irish Seas. The distinction in feeding ecology which may explain the birds’ varying fortunes is that, in the southern parts of the range, puffins can prey on sprats when sand eels are scarce. Sprats appear to have suffered none of the disruption that assails the other fish.

But Dunn says it is important to look at the whole picture. “It’s fantastic that puffins are doing well in places like the Farnes, but remember: Britain holds less than 10 per cent of the world total. Also, the declines that have beset puffins in Shetland and St Kilda are even worse for other seabirds.”

The numbers of a silver-winged gull called the kittiwake have fallen by 90 per cent in Shetland and St Kilda since 2000 and by 80 per cent in the Orkneys in just ten years. Shetland’s guillemot numbers have also halved, and the shag, a relative of the cormorant, has experienced falls of over 80 per cent on many islands since the 1970s – 98 per cent, on Foula. Most troubling is the fate of the Arctic skua, which feeds mainly on fish it steals from other seabirds and is reliant on their successes. Its declines are so severe that Dunn fears its eventual loss as a breeding species in Britain.

While there is disagreement about what to call the puffin predicament, there is unanimity on one issue: much of the data that informs the discussion in Britain is out of date. All of these seabirds, which are of global importance, have been monitored decade by decade since the 1970s. Yet the most recent big audit of our cliffs and offshore islands was concluded in 2000. The full census data is now 16 years old. The organisation that underwrites this work is the Joint Nature Conservation Committee; it is sponsored by the Department for Environment, Food and Rural Affairs, which has suffered deep budget cuts since the 2008 financial crisis. There is no certainty that another comprehensive census will be mounted any time soon.

“Much is made on wildlife television of how special these islands are for wildlife and how much we care about it,” Dunn says. “In the case of our seabirds, one of those claims is indisputably true. Britain holds populations of some species that are of worldwide significance. But if we lack even basic information on those birds and how they’re faring, especially at a time when our seas are in such flux, what message does that send about how much this country cares? And how can we ever act effectively?”

The plight of the puffin is shedding light on the fortunes of our marine wildlife generally and the shifting condition of our oceans as a result of rising carbon-dioxide levels. Now, puffin politics is also starting to show
this government’s indifference to nature.

This article first appeared in the 28 July 2016 issue of the New Statesman, Summer Double Issue