OSLO Likely headlines predicting a global warming "catastrophe", "disaster" or "cataclysm" after a U.N. report due on Friday risk sapping public willingness to act by making the problem seem too big to tackle, some experts say.
The world's leading climate scientists, meeting in Brussels, are set to warn of more hunger in Africa, rising seas, species extinctions and a melting of Himalayan glaciers in the April 6 report about the regional impacts of climate change.
But the United Nations' Intergovernmental Panel on Climate Change (IPCC), grouping 2,500 scientists, does not use words to sum up the forecasts -- unlike some politicians or headline writers who describe it as a "crisis", "terrifying" or "Armageddon".
"I'm a bit preoccupied that the media, having contributed to every day making another doomsday news headline, then in six weeks time will declare it hysteria and move on," said Achim Steiner, head of the U.N. Environment Program.
Still, Steiner said it was clearly right to use words like "catastrophe" to describe effects such as a projected rise in sea levels in coming centuries that could swamp Pacific island states or cities from Shanghai to Buenos Aires.
"It is legitimate to use those words in specific scenarios," he told Reuters. "But does that mean that the whole climate change debate should be about doom and gloom? No, because we are finding that we can do something about it."
Mike Hulme, head of the British Tyndall research Centre, said headlines in the British media after a previous U.N. report in February, giving an overview of global warming science, used adjectives such as "shocking", "terrifying" or "devastating".
"Such appeals often lead to denial, paralysis, apathy and even perverse reactive behavior," he wrote in a letter to the journal Nature. He said U.S. media used less startling language.
"Campaigners, media and some scientists seem to be appealing to fear in order to generate a sense of urgency," he wrote. "If they want to engage the public in responding to climate change, this is unreliable at best and counter-productive at worst."
And skeptics, meanwhile, say strong words exaggerate dangers. U.S. Republican Senator James Inhofe in 2003 called the threat of "catastrophic global warming ... the greatest hoax ever perpetrated on the American people".
U.N. officials say the IPCC wants to avoid allegations of scaremongering in its reports that link greenhouse gases from burning fossil fuels to warming. That means many people need a dictionary to read IPCC reports.
The IPCC's main conclusion in its February report was that it was more than 90 percent probable that mankind was to blame for most global warming since 1950.
It wrote: "Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations." Anthropogenic means caused by humans.
Some U.N. agencies use clearer language.
"The matter is serious," according to the U.N.'s Climate Change Secretariat in Bonn. "Predictions of future climate impacts show that the consequences could vary from disruptive to catastrophic."
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