The United Nations climate panel may have to change its claim that global warming has led to more hurricanes and tropical storms in recent years.

The Intergovernmental Panel on Climate Change said the evidence that the world was warming was "unequivocal".

The London Times reports the latest research suggests that the rise in the number of hurricanes since 1995 was simply part of a natural cycle.

The study indicates that there have been many similar cycles and all of them were followed by a decline in the number of hurricanes.

The research goes on to suggest that in the decades ahead, instead of leading to more such storms global warming could actually reduce the number of tropical storms by up to 34 percent.

But some scientists are suggesting the world may not be growing warmer each year.

"The temperature records cannot be relied on as indicators of global change," said John Christy, professor of atmospheric science at the University of Alabama in Huntsville, a former lead author on the IPCC, told the Times.

Other scientists say the earth has gone through warming spells at least twice in the last 1,000 years.