Reports link heat waves, deluges to climate change

The D.C. region has experienced intense warming in recent years as well. In the past two years, Washington has experienced its two hottest summers on record (2010 and 2011), second-warmest spring (2010) and third-warmest winter (2011-12) since records began in 1871.

Across the United States this year so far, warm weather records have outnumbered cold records by a factor of 12, according to the National Oceanic and Atmospheric Administration’s National Climatic Data Center.

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 This year has been an unprecedented one for natural disasters. By the end of June, economic losses totaled $265 billion, according to German reinsurer Munich Re. That easily exceeds the total figure for 2005, which was previously the costliest year.

Coumou used a “loaded dice” analogy popular with climate scientists. Rolling one six is not evidence of a loaded die. Rolling 10 in a row? Now you’re suspicious. Human-induced climate change has loaded the dice toward certain extreme events, Coumou said.

Environmentalists and major insurers argue that policymakers must move quickly to cut carbon emissions and devise strategies to adapt to climate impacts.

“The IPCC report is yet another reminder of the pressing need to tackle climate risk in both the near and long term,” said Mark Way, head of sustainability for the Americas at Swiss Re. In 2011, insurers paid out $35 billion to cover weather-related losses in the United States, he added.

Although extreme weather in developing countries exacts a higher human toll than in industrialized nations, the high economic cost of recent U.S. disasters is shifting more of the financial burden to taxpayers.

Cynthia McHale, who runs the insurance program at Ceres, a nonprofit network that addresses issues of environmental sustainability,said the National Flood Insurance Program now has $1.2 trillion of commercial and residential assets on its books.

“If we continue on this path, extreme weather is certain to cause more homes and businesses to be uninsurable in the private insurance market, leaving the costs to taxpayers or individuals,” McHale said.

On Wednesday, Lloyd’s of London posted its first pretax loss in six years, citing the burden of natural catastrophes in 2011. That year now ranks as the second-most expensive on record for insured disaster claims worldwide, with $100 billion to $116 billion in claims.

The IPCC report identifies “no regrets” strategies that policymakers can pursue to reduce the risk of disasters while promoting sustainable development and climate adaptation, including early-warning systems for hurricanes and better building design and regulation to lower the impact of flash floods.

“There are lots of opportunities which pay off,” said Field, who co-edited the report.

Staff writer Jason Samenow contributed to this report.