The worst weather ever? At $200bn, it's certainly the costliest

Severe weather around the world has made 2005 the most costly year on record with unprecedented levels of insurance claims on damaged property, the United Nations Environment Programme says.

Early estimates made by the insurance company Munich Re Foundation put the year's financial losses at more than $200bn (£117bn) with insurance claims running at more than $70bn. In 2004, the previous most costly year for weather-related incidents, losses totalled about $145bn and claims reached $45bn.

The UNEP said this year's record was partly due to the highest number of hurricanes and tropical storms since records began more than 150 years ago. Some scientists believe the upsurge in cases of severe weather may be linked to climate change brought about by man-made emissions of greenhouse gases.

Thomas Loster, chief executive of Munich Re Foundation and a member of the finance initiative of the UNEP, said the global weather in 2005 was exceptional in many ways: "There is a powerful indication from these figures that we are moving from predictions of the likely impacts of climate change to proof that it is already fully under way."

"Above all, these are humanitarian tragedies and show us that, as a result of our impacts on the climate, we are making people everywhere more vulnerable to weather-related natural disasters."

The year also saw the highest recorded instance of rainfall, 944mm in 24 hours in Mumbai, India; the first hurricane to reach the European mainland; and the strongest hurricane on record. Hurricane Vince was the first to make landfall in Europe when it hit the Spanish coast in October. In November, Tropical Storm Delta hit the Canaries killing several people. It was the first tropical storm to strike the islands.

Munich Re Foundation collects some of the best data in the world on economic losses and insurance claims due to natural disasters, the UN agency said. Losses due to atmospheric-linked disasters showed a far stronger upward trend than those related to earthquakes for the past 50 years, Mr Loster said.

"We do not underestimate the human tragedy of earthquakes which can kill tens of thousands of people a year. But our findings indicate that it is the toll of weather-related disasters that are on the rise," he said.

The Atlantic hurricane season this year broke many records. Hurricane Wilma in October was the strongest storm ever recorded, and there were so many tropical storms that the US National Hurricane Centre exhausted its list of 21 alphabetically ordered names. Not all scientists are convinced climate change is responsible for the upsurge in severe weather, but many computer models predict such events could occur more frequently in a warmer world.

Klaus Toepfer, executive director of the UNEP, called on the climate change convention being held in Montreal to reach agreement and send a clear signal to business and governments.

"We must find the political will and the funds necessary to help the most vulnerable people adapt to the climate change now under way," Mr Toepfer said.