Here’s a good piece at The Times Online by Bryan Appleyard, explaining how he changed from climate sceptic/denier to accepter of the scientific evidence for global warming: Global warming is real.
There are so many good reasons not to believe in global warming: summers lately have been cool and wet; since 1998 global temperatures have actually fallen; dissident scientists say it’s not happening; green believers are irritating — they wear Tibetan hats that only look good on Tibetans, and are so often wrong that they’re probably wrong about the Big One; large parts of the punditocracy say it’s all nonsense, usually that it’s a left-wing plot against capitalism; the rainforest is growing back faster than it’s being cut down and polar bears are, apparently, doing quite well. Global warming? Yeah, right!If we don’t look after it, who will?
But here’s the best reason of all not to believe, to sit back and relax. Global warming is just the latest apocalyptic story. There is always someone, somewhere predicting the end of the world.
He may be a man with a sandwich board in Oxford Street or an American Christianist who expects the Book of Revelation to happen tomorrow. But he’s equally likely to be a scientist warning about asteroid impacts, super-eruptions, molecule-sized robots turning everything into grey goo or, not so long ago, the descent of Earth into a new ice age. Taking all these possibilities into account, Sir Martin Rees, the great cosmologist, says humans only have a 50/50 chance of making it into the next century. Yeah, right!
No wonder opinion polls show a majority of the population are sceptical about global warming. Just scanning the papers, the internet or watching TV is enough to convince anyone it’s just the usual apocalyptic hype. And, if they want to dig deeper into their own disbelief, there are shelfloads of books to give them a hand. There’s Nigel Lawson, ex-chancellor of the exchequer, with An Appeal to Reason. There’s Scared to Death by Christopher Booker and Richard North. There’s Cool It by Bjorn Lomborg. There was even a very serious documentary on Channel 4 called The Great Global Warming Swindle with some serious-looking science guys pouring cold water on the warming atmosphere.
Just a couple of weeks reading and watching and you can be out there, crushing dinner-party eco-warriors with devastating arguments based on cold, hard facts. You will be a stern, hard-headed denialist, your iron jaw set firmly against the tree-hugging, soft-headed warmists in their irritating hats.
That was me, once. I thought global warming was all bog-standard, apocalyptic nonsense when it first emerged in the 1980s. People, I knew, like nothing better than an End-of-the-World story to give their lives meaning. I also knew that science is dynamic. Big ideas rise and fall. Once the Earth was the centre of the universe. Then it wasn’t. Once Isaac Newton had completed physics. Then he hadn’t. Once there was going to be a new ice age. Then there wasn’t.
Armed with such historic reversals, I poured scorn on under-educated warmists. Scientists with access to the microphone, I pointed out, had got so much so wrong so often. This was yet another case of clever people, who should have known better, running around screaming, “End of the World! End of the World!” and of less-clever people finding reasons to tell everybody else why they were bad. And then I made a terrible mistake. I started questioning my instinct, which was to disbelieve every scare story on principle.
I exposed myself to any journalist’s worst nightmare — very thoughtful, intelligent people.
I talked to some brilliant scientists and thinkers, some mainstream Greens, some truly tough-minded scientists. There was James Lovelock, the man whose Gaia hypothesis sees the world as a single, gigantic organism. There was Jesse Ausubel, director of the Program for the Human Environment at Rockefeller University in New York. There was Chris Rapley, director of the Science Museum and former head of the British Antarctic Survey. There was Myles Allen, head of the Climate Dynamics Group at Oxford. There was Sir David King, once chief scientific adviser to the British government. There were many others.
There is, I saw, a fine line between the hard-head and the bone-head. The denialist hard-head swaggers his way through life hearing only what he wants to hear, that warmism is either a hoax, a gross error or just another End-of-the-World scare story. But if you suspend your prejudices and your vanity for a moment, everything changes. You find out that the following statements are true beyond argument.
The climate is warming. It is almost certain this is caused by emissions of greenhouse gases caused by human activity. Nobody has come up with an alternative explanation that stands up. If the present warming trend continues, nasty things will probably start happening to humans within the next century, possibly the next decade. Something must be done. If nothing is done, then the benign climatic conditions that have sustained human civilisation for 10,000 years are in danger of collapse to be replaced by… well, write your own disaster movie.
You will note that there is some wiggle room in these statements. It is “almost certain” that humans are responsible; nasty things will “probably” happen. That is because all science can ever be is the best guess of the best minds. Also, the climate is a complex system, meaning it can behave in ways that are opaque beyond our most sophisticated calculations. But, as I have often been told, those statements are as true as any scientific statements can be, and nobody — I repeat, nobody — has been able to refute this. In short, to deny any of these statements is to put yourself beyond the bounds of rational discourse.
Beginning from the beginning. In 1750 there were 800m people in the world. Then came the Industrial Revolution. This required almost pure carbon, coal, oil and gas to be taken from the ground where it had lain for millions of years, burnt and tossed into the atmosphere as carbon dioxide. Now there are almost 7 billion of us and we toss 27 billion tons of carbon dioxide — 7.3 billion tons of pure carbon — into the atmosphere every year. Since the Industrial Revolution, the total amount tossed is half a trillion tons of pure carbon. It is impossible to say this didn’t happen and bone-headed madness to think it will have no effect. We are more or less certain that the effect has been a one-degree-centigrade rise in global temperature.
What do the deniers say about this? “The world’s temperature rose about half a degree centigrade during the last quarter of the 20th century,” writes Nigel Lawson, “but even the Hadley Centre for Climate Prediction and Research… has now conceded that recorded temperature figures for the first seven years of the 21st century reveal there has been a standstill.”
Actually, er, bollocks. In the staff cafe at University College London, Chris Rapley draws me a graph showing temperature fluctuations over the past million years. He draws an even rising-and-falling line. Then he corrects himself and the even line becomes a jagged landscape of peaks and troughs. But the trend line remains clear. So yes, if you start in 1998 — a very hot year thanks to an intense El Niño event in the South Pacific — and draw a line to a cool year, 2007, you get a falling line. Nevertheless, the average temperature for this decade is higher than the previous one. The trend is intact. Anyway, back to basics. Half a trillion tons of carbon came as a shock to planet Earth. Antarctic ice cores reveal that for about 1m years, atmospheric carbon fluctuated between ice-age levels of 180 parts per million (ppm) and warm levels of 280ppm. We don’t know why this narrow fluctuation was so stable. It just was.
Carbon levels are now at 387ppm and rising rapidly. The best we can hope for, if radical low-emission targets are accepted by world governments NOW, is to stabilise the figure at 450ppm. That will mean a further one-degree temperature rise. This could be nasty — more hurricanes, rising sea levels, spreading deserts, loss of arable land — but maybe manageably so.
At this point, deniers often talk about the medieval warm period. From about 800AD to 1300AD, temperatures rose by, at one point, more than they are rising now. Fair enough, except this wasn’t a global phenomenon, it was purely European. The Earth as a whole cooled.
Having lost that one, the next denialist move is the Sunspot Gambit, much in evidence in that Channel 4 documentary. Mention that show to Rapley and he loses his amiable manner. “I was scandalised. I shall never, ever, forgive Channel 4 and if I ever find a way of preventing them having public funds then I shall exercise it.”
The idea behind the Sunspot Gambit is that global temperature trends are dependent on solar activity. Well, it’s true, they are, a bit. But the idea that large-scale trends are caused by “solar forcing” is wrong. The good thing about being a Spottist is you can be right for 11 years at a time. That’s the length of the sunspot cycle, so you can construct a theory based on one cycle and be sure that it will not be knocked down by the next for 11 years.
Back to reality. Myles Allen at Oxford has a vivid way of simplifying the scale of the task involved in preventing carbon levels rising above 450ppm. The modern world has been built on half a trillion tons of carbon. At present rates of increase we will burn the next half trillion tons in 40 years. The best guess is that that will result in a one-degree rise. There are, perhaps, four to five trillion tons of burnable carbon still in the Earth. But the maximum we can burn is half a trillion tons. In Copenhagen, therefore, the talks should be about allocating that half trillion as if it were a gigantic carbon cake. To make this work and ensure we don’t burn more than that, Allen goes for a radical option. “It will only work,” he says, “in the context of a plan to get emissions down to zero by the end of the century. So I think we need what none of the politicians seems prepared to acknowledge. A rationing system for putting carbon dioxide into the atmosphere is only a temporary measure; eventually the whole practice has to be banned.”
This should give you vertigo. You are peering into a carbon-free abyss. If we stopped burning carbon now, you and I, as Rapley points out, would starve to death in a week. Burnt carbon is our money, our lifestyle, our sense of who we are. The revolution is just too big to contemplate.
Enter Bjorn Lomborg. Lomborg is not a denier, but he is a denialist hero, because he gave them their one really strong argument for doing nothing or next to nothing. Global warming is happening, he says, and it’s a problem, but it’s not a BIG problem and certainly not so big that we have to ditch our way of life. The reason this is a strong argument is that it doesn’t make the mistake of denying the science — futile, as Lomborg knows and as I hope you do by now — it just says that the outcome may not be that bad. Scientists can’t say he’s wrong because the future of a complex system — climate combined with human civilisation — is inherently unpredictable.
It’s all a question of probability and risk. Rapley once put it to me this way. You are putting your daughter on a plane. The pilot tells you there is a 1-in-100 chance it will crash. You, if you have any sense, take your daughter off the plane. Why? Because the potential loss is so great that 1 in 100 is unacceptable. So it is with global warming — except the down side probability is a good deal higher than 1 in 100.
The economist and academic Lord Stern, appointed by the government in 2005 to investigate the economics of climate change, tried to put exact figures on this. His 2006 report has become the standard document justifying action on global warming, which Stern calls the greatest market failure in history. Personally, I think the Stern report may turn out to have been a disaster. This is because Stern is an economist and economists obfuscate matters. He recommended allocating 1% of the world economy to fighting climate change and to prevent what he said would be a 20% drop in the world economy due to warming.
Stern’s figures were based on a financial assessment of the impact of global warming on future generations. The trouble with this is that it’s a very difficult and controversial calculation and one which economists love to argue and get upset about. Many queued up to trash Stern’s assumptions. This provided the denialists with a glut of ammunition and further confused the poor punters.
Put it like this. Here are these scientists telling you probably your children and almost certainly your grandchildren are going to lead screwed-up lives thanks to our carbon emissions, and here are these economists arguing about the monetary value of their screwed-upness. Case closed.
Far stronger than all this are simple, empirical observations. Rapley points out that sea temperatures are rising exactly as predicted by the climate models. Climate change, more than over-fishing, has been found to be behind the fall in North Sea fish stocks. Arctic ice is melting faster than expected. And here’s one fact that should give the most hardened bone-head pause: Arctic shipping lanes are to be re-opened. Summer sea ice in 2007 was 40% down on the average, and shipping companies are planning much faster routes between Europe and Asia using the Arctic Ocean. These guys are not exactly tree-huggers. And yet many denialists still insist on saying there’s no problem with the Arctic melt.
One big general denialist argument is about climate models. These are fabulously complicated computer programmes that attempt to model the Earth’s atmosphere. The number-crunching is so vast that Myles Allen has contracted it out to you and me. He began Climateprediction.net, which uses downtime on people’s home computers to run climate simulations. Try it. You should. The idea is to cut the uncertainties in the models. And there are, no question, huge uncertainties. All complex systems are uncertain. But, for two closely related reasons, the denialists are wrong to claim this as an argument in their favour. First, empirical evidence either shows the models are right or, especially in the case of Arctic ice, that they are understating the problem. Lovelock, in particular, says this understatement has given us a model-based false sense of security. The disaster is coming much sooner than we thought.
Secondly, the very inadequacy of the models is a reason for even greater caution. The big picture the models show is simple — carbon is rising and temperatures are rising. This is known as a linear system. It’s like a multiplication table: 2 x 2 = 4, 2 x 3 = 6 and so on. So add half a trillion tons of carbon to the atmosphere and the temperature rises by one degree. Technically, the output bears a fixed relation to the input.
But we know the atmosphere is subject to non-linearity. You may get the same result over and over again until, one day, you don’t. Suddenly 2 x 2 = 5. Then the output-input relationship varies wildly. This can happen in any complex system. Imagine a pile of sand. You keep dropping extra grains on top. You might drop a million grains and nothing happens. Then you drop a million and one and it collapses. If you push any such system hard enough, it will slip into non-linearity. At which point steal tents, canned food and assault weapons.
In other words, pushing another half trillion tons of carbon into the atmosphere should raise temperatures by a degree or so, but it might raise them by much more. Or it could start climate flickering in which climate changes repeatedly from one state to another every few years. It’s happened in the past. Either way, you can kiss your way of life goodbye.
The reality of non-linearity and complex systems is actually the most basic and irrefutable argument for cutting emissions. As Nassim Nicholas Taleb, author of The Black Swan, put it to me, it doesn’t matter about the exact rights or wrongs of the science, it doesn’t matter whether you think warming is caused by human activity. What matters is the general principle that you do not disturb complex systems. Half a trillion tons is a disturbance and Nassim is a real Green.
In the end, it comes down to August 14, 1959. That was when the US satellite Explorer 6 sent back the first picture of Earth from space. The enormity of this moment, however, did not sink in. Many people still think the first picture came almost a decade later, in December 1968, when Apollo 8 sent back its beautiful “Earthrise” photograph. Either way, it was a moment when something we knew in our heads became thrillingly, terrifyingly real in our hearts.
The pictures showed a small planet lost in darkness. A thin film of life interacting with a narrow band of atmosphere produced the astonishing, swirling pattern of clouds, the dark seas and the darker continents. We have, in spite of our vanities and intergalactic dreams, nothing and nowhere else. If we don’t look after it, who will?
Go to that dinner party, wear a Tibetan hat if you must, and look for the iron-jawed bone-head. There’s usually at least one, and it’s usually a man. Look him in the eye, smile and ask him one question: “Who on Earth do you think you are?” He’ll get it on the sixth attempt.