Politicians Outstrip Science In Race To Be Green.
Politicians are convinced they must save the world from global warming, but scientists are hesitating, saying nothing has been proved yet.
And some experts say heavy-handed measures to stop warming may do more harm than good. World leaders at last month’s United Nations Earth Summit in New York called for sharp cuts in emissions of so-called greenhouse gases like carbon dioxide (CO2).
Europe’s call for a cut in emissions of 15 per cent below 1990 levels by 2010 implies a drastic change in lifestyles. Car use would have to be slashed, and tough energy conservation measures undertaken.
Britain’s Prime Minister Tony Blair leapfrogged his European partners, aiming for a 20 per cent cut.
Some U.S. industrial groups and trade unions have said such cutbacks would merely export jobs and pollution to Latin America and Asia, which would not initially have to conform to emission limits while their less developed economies catch up with the West.
But while the politicians compete to flaunt their green credentials, they are racing way beyond science. Most scientists are still reluctant to say there is a definite link between the works of man and the increase in global temperatures of about half a degree Celsius since the late nineteenth century.
Many politicians and environmental activists point to a report by the U.N.’s Intergovernmental Panel on Climate Change as the basis for their fears about the future of world temperatures.
But this report has been criticised by some scientists who say the conclusions exaggerate the research findings.
An IPCC report published in 1996 concluded that the influence of man on climate change had been proven. But critics said this was not backed up by the detail of the report.
Even prominent authors of the report have backed away from hard and fast conclusions.
Balance Of Evidence
“‘The balance of evidence suggests the influence of man’ is a relatively cautious phrase, suggesting evidence both for and against,” said Dr Ben Santer, lead writer of the IPCC report.
“We concluded that if you looked at the totality of the scientific evidence, yes, more of it points towards a human effect on climate than against, but there are still significant uncertainties.
“There is a distinction between detection and attribution,” said Santer, atmospheric scientist at the Lawrence Livermore National Laboratory, in Livermore, California.
“This doesn’t give the cause of change, attribution is very difficult. No scientist can claim unambiguous attribution, it is not settled beyond a doubt,” Santer said in a recent interview.
“To be unambiguous it would convince a majority of scientists (warming) was only due to human causes and nothing else, and we are some way from that,” Santer said.
Some academics say government action is justified because there is enough statistical evidence to demonstrate that the climate is warming.
Waiting could be fatal, they say.
“It might take from 15 to 50 years to prove conclusively that mankind is warming the planet, and by then it may be too late. It’s like lung cancer and cigarettes. The statistical link was established. You wouldn’t wait to get lung cancer before you said it was proven would you,” said Ron Beard, head of Geography at the University of Luton, in central England.
But researchers continue to back down from scenarios which had pointed to disaster.
The British Meteorological Office’s Hadley Centre for Climate Change forecast in 1989 that a world with twice the pre-industrial level of carbon dioxide would warm from 1.9 to a devastating 5.2 degrees.
Chopping And Changing
It recently upgraded its computer model and said temperatures would probably rise three degrees over the next 100 years, assuming just over twice the level of CO2 in the atmosphere than in pre-industrial times.
The IPCC said in 1990 that average temperatures would rise an average 3.2 degrees by 2100. In 1992 this was cut to 2.5 degrees.
Critics say computer models have been hopelessly inadequate and do not promise much improvement in the foreseeable future.
Predictions have failed to use satellite data and, because most measurements are centred on towns and cities, may simply reflect increased urbanisation. No measurements have reflected weather over the oceans, which cover about 70 per cent of the world’s surface.
Michael Warby, public affairs manager for the Tasman Institute, in Melbourne, Australia, said in a recent article in the Wall Street Journal that the cost of cutting back CO2 emissions would be so severe on world economies that it would damage human health, life expectancy and welfare more than global warming.
More Important Issues Than Global Warming
“There are much more important environmental issues than global warming, such as water purity, air pollution, land and other resource management and coastal protection that are affecting the health, life expectancy and prosperity of people,” he told Reuters.
Livermore National’s Santer agrees that computer models lack credibility but suggests evidence is beginning to build up that may justify action.
“The unreliability of models is a problem, but greenhouse gases are up by 30 per cent since the end of last century. It is indubitable that human activity has changed the chemical content of the atmosphere, that’s not in dispute. But how much impact will that have on the climate of the future?” Santer said.
“There are some things that we seriously have to sorry about– sea level, the amount of precipitation — that could hurt societies and economies in very important ways.
“There is uncertainty. Should we wait for absolute certainty?”
Neil Winton – July 1997