Put your money where your ‘myth’ is

Meet the Ivy League professor and expert on forecasting who is challenging Al Gore to a $20,000 bet that he is wrong on global warming.

Spiked, June 25, 2007

http://www.spiked-online.com/index.php?/site/printable/3533/

By Brendan O’Neill

Al Gore’s doom-mongering documentary An Inconvenient Truth - in which he turned his rather drab PowerPoint presentation on climate change into a cinematic warning to the world about man’s toxic impact on the planet - has generated miles of newspaper column inches. He’s won widespread praise from greens for converting ‘ordinary people’ (ie, the previously uncaring popcorn-chomping masses) to the green cause. He’s been given a telling-off by some climate scientists for twisting the data in order to send a moral message about mankind’s destructiveness (1). Others have accused him of being a hypocrite: apparently Gore, who has two very big homes, used 221,000 kilowatt hours of electricity in 2006, 20 times the American national average (2). And now, in the latest post-Truth twist, Gore has been challenged to a $20,000 wager that he is wrong on global warming.

‘The aim of the bet is really to promote the proper use of science, rather than the opinion-led science we have seen lately.’ Scott Armstrong is professor of marketing at the Wharton Business School at the University of Pennsylvania, and an international expert on forecasting methods. Last week he faxed and posted (to be on the safe side) his ‘Global Warming Challenge’ to Gore. He challenged the former US vice-president to a 10-year bet in which both parties will put forward $10,000. Gore would put his money on his forecasts that temperature will rise dangerously in the coming decade, while Armstrong will put his money on what is referred to as the ‘naïve model’: that is, that temperatures will probably stay the same in the coming years. ‘Gore says there are scientific forecasts that the Earth will become warmer very rapidly. But I have not found a scientific forecast that supports that view. There are forecasts made by scientists, of course, but they are very different from a scientific forecast’, says Armstrong.

Armstrong got the idea for the climate change wager from the late Julian Simon, an economist at the University of Maryland who was a friend of Armstrong’s. In 1980, Simon bet the population scaremonger Paul Ehrlich that natural resources were not scarce and shrinking, as Ehrlich and other Malthusian environmentalists claimed. Ehrlich accepted: he chose five metals (copper, chrome, nickel, tin and tungsten) and bet Simon that in 10 years’ time the price of these metals would have risen exponentially due to their continued depletion by human adventure. In fact, when 1990 arrived, the price of all of Ehrlich’s metals had fallen. Simon won the bet and Ehrlich handed him a cheque for $576.07. Armstrong expects to win his bet with Gore, too (that’s if Gore accepts; he hasn’t responded yet). But even if he were to lose, ‘at least I will have started a debate about forecasting’, he tells me.

Armstrong and his colleague Kesten Green, senior research fellow at Monash University in Australia and also an expert on forecasting, have been conducting research into the global-warming forecasts put out by Gore and organisations such as the Intergovernmental Panel on Climate Change (IPCC). And they discovered that most climate-change forecasters use bad methodology. They are set to present their findings at an International Symposium on Forecasting in New York on Wednesday. ‘What we have is climate forecasters effectively translating their own opinions into maths’, says Armstrong. ‘Their claims are not built on clear and thorough scientific forecasts but on their own outlooks.’ In Global Warming: Forecasts by Scientists versus Scientific Forecasts – the paper they are presenting at the symposium, which spiked has seen – Armstrong and Green point out that the IPCC’s Working Group One Report predicted ‘dramatic and harmful increases in average world temperatures over the next 92 years’, and they ask: ‘Are these forecasts a good basis for developing public policy?’ The answer provided in their paper is an emphatic ‘no’ (3).

Armstrong and Green – whom I’m sure won’t mind being referred to as forecasting geeks – argue that those who predict sweeping changes in the climate break many of the golden rules of forecasting, as laid out in the 2001 book The Principles of Forecasting. In their paper, they assessed ‘the extent to which long-term forecasts of global average temperatures have been derived using evidence-based forecasting methods’. They surveyed 51 scientists and others involved in making global-warming predictions, asking them to provide scientific articles that contained credible forecasts to underpin their view that temperature will rise rapidly. Most of those surveyed – 30 out of 51 – cited the IPCC Report as the best forecasting source. Yet according to Armstrong and Green, the forecasts in the IPCC Report are not the outcome of scientific forecasting procedures – rather the Report presents ‘the opinions of scientists transformed by mathematics and obscured by complex writing’ (4). Indeed, in their ‘forecasting audit’ of the IPPC Report, Armstrong and Green found that it violated 72 of the principles of forecasting.

Such as? ‘Well, some of the principles of forecasting can appear counterintuitive, so bear with me’, says Armstrong. ‘One of the principles is that agreement amongst experts is actually not a very good measure of accuracy. This is especially true if experts are working closely together, and towards a certain goal, as they do in the IPCC. Such an atmosphere does not tend to generate reliable or accurate forecasts. Another principle of forecasting is that when there is uncertainty, your forecasts should be conservative, you should hedge your bets a little bit. The IPCC and others do exactly the opposite: despite their uncertainty, the fact that they don’t know for certain what will happen, they are radical in their predictions of warming and destruction and so on.’

The IPCC Report violated these two principles of forecasting, claims Armstrong, and 70 more. As an example of why forecasting needs to be done properly, in their paper for the symposium he and Green point to various headlines that have appeared in the New York Times over the past 80 years. On 18 September 1924: ‘MacMillan Reports Signs of New Ice Age.’ On 27 March 1933: ‘America in Longest Warm Spell Since 1776.’ On 21 May 1974: ‘Scientists Ponder Why World’s Climate is Changing: A Major Cooling Widely Considered to be Inevitable.’ (5) ‘Those forecasts were made with a high degree of confidence, too’, he says. ‘Where are they now? It is very important that forecasts are built on proper forecasting principles, and that uncertain forecasts are treated as such.’

Armstrong and Green may have a point about the IPPC Report consisting more of scientists’ opinions rather than scientifically validated forecasts of temperature change. And it will be interesting to see if Gore accepts their bet. But I can’t help wondering if one of the main problems with the debate about climate change today is precisely the focus on forecasting, whether it is the allegedly wild forecasting contained in the IPCC Report or the more principled forecasting proposed by Armstrong and Green.

To debate the future on the basis of scientific forecasts about temperature is to denigrate human activity and impact. Humans don’t, or at least shouldn’t, sit around waiting for the inevitable to occur; we are capable of shaping our world and of addressing and solving problems as they arise. The Forecast View of History – which takes climatic developments of the past and measures them against the present, in order to make predictions about the future – tends to be fatalistic, viewing humans as objects of history rather than as creators of change. Perhaps we should spend less time forecasting what will (allegedly) happen, like modern-day tealeaf-readers, and more time making things happen in the way we want and need them to. I would put my money on human ingenuity over scary weather forecasts any day of the week.

CSPP Note: Professor Armstrong’s paper, “Auditing Public Policy Forecasting: Climate Change, Gun Control, and Other Issues,” which he presented at the 27^th International Symposium on Forecasting, is available in this issue of Climate & Environment Review.