UNITED NATIONS

The economic cost of disasters in 2011 was the highest in history — with a pricetag of at least $380 billion, mainly due to earthquakes in Japan and New Zealand, a U. N. envoy said Monday.

Margareta Wahlstrom, the secretary-general’s special representative for disaster risk reduction, said the figure was two-thirds higher than the previous record in 2005 when Hurricane Katrina struck the southern United States.

In addition to the earthquakes,

Wahlstrom said major floods in Thailand and other countries caused extensive damage.

“The main message is that this is an increasing — very rapidly increasing trend with increasing economic losses,” Wahlstrom said.

Despite the rising costs, she said, deaths from disasters are proportionally declining because countries are getting much better at instituting early warning systems and preparedness measures.

“But the economics of disasters is becoming a major threat to a number of countries,” Wahlstrom said.

“We say today that 50 percent of the world’s population is exposed to disaster risks because they live in the highly vulnerable areas,” she said.

Wahlstrom said Japan has the highest economic exposure and the second-highest population exposure to potential disasters.

She praised Japan for its preparedness efforts but said there are lessons to be learned from the magnitude 9.0 earthquake and tsunami on March 11.

While buildings generally withstood the massive quake, the tsunami that followed engulfed the northeast, wiped out entire towns, and inundated the Fukushima nuclear powerplant, triggering the worst nuclear accident since Chernobyl.

Wahlstrom said the risk of disasters is increasing globally because of climate change, the depletion of natural resources, poor land use, and worsening environmental problems.