---

Hurricanes and global warming - a link?
...Take the president of the world's most powerful nation. Add two intense and damaging natural storms which bring destruction to that country; then mix in the widely held view that the same nation's environmental policies are partially responsible for those storms.

In the polarised world of climate change, this cocktail has proved an irresistible temptation to organisations which campaign against President Bush's administration in support of enhanced action to curb greenhouse gas emissions.

The latest to succumb was the British newspaper The Independent, which screamed on its front page: "This is global warming", above an alarmingly portentous graphic of Hurricane Rita's projected path.

But is it global warming? What is the evidence that the growing concentrations of carbon dioxide and other greenhouse gases in the atmosphere are changing weather systems in such a way that hurricanes become more powerful, or more frequent?

Certainly, 2005 appears to have been an unusually active year.

The US National Hurricane Center/Tropical Prediction Center comments in its August summary that "thus far in 2005, there have been 12 named storms and four hurricanes.

"These numbers are well above the long-term averages of 4.4 storms and 2.1 hurricanes that would normally have formed by this date."

But a single year's observation does not permit the divination of a long-term trend, or the attribution of that trend to a cause such as climatic warming.

"Based on recent research, the consensus view is that we don't expect global warming to make a difference to the frequency of hurricanes," explains Julian Heming, from the UK Meteorological Office.

"Activity is naturally very variable in terms of frequency, intensity and regional occurrence; in the Atlantic, there are active phases and not so active phases, and currently we're in the middle of an active phase.

"It's very dangerous to explain Rita or Katrina through global warming, because we have always had strong hurricanes in the USA - the strongest one on record dates back to 1935." ...

... Now that climate scientists are being taken seriously, they are also under pressure to produce instant answers.

One problem is that not all of those answers exist. Another problem is that some scientists - not to mention lobby groups, environmental organisations, politicians, newspapers and commentators - will go much further in their public statements than the data allow.

With such incendiary material, that is unlikely to change; but it is difficult to avoid the conclusion that we would all benefit from people on both wings of the issue looking rather more to research, however laboured its progress, and rather less to screaming headlines and easy quotes.