The United States has already tied its yearly record for billion-dollar weather disasters and the cumulative tab from floods, tornadoes and heat waves has hit $35 billion, the National Weather Service said on Wednesday.
And it’s only August, with the bulk of the hurricane season still ahead.
“I don’t think it takes a wizard to predict 2011 is likely to go down as one of the more extreme years for weather in history,” National Weather Service Director Jack Hayes told journalists on a conference call.
The number of billion dollar disasters in any year, by itself, isn’t a scientific measure of climate change, since many factors influence the cost of weather disaster. On the other hand, the scientific literature has been clear for a while that human emissions are making the weather more extreme, as predicted by climate scientists (see “Two seminal Nature papers join growing body of evidence that human emissions fuel extreme weather, flooding that harm humans and the environment“).
And last year, Munich Re, one of the world’s leading reinsurers, issued a news release in late September, “large number of weather extremes as strong indication of climate change,” which concluced:
Munich Re’s natural catastrophe database, the most comprehensive of its kind in the world, shows a marked increase in the number of weather-related events. For instance, globally there has been a more than threefold increase in loss-related floods since 1980 and more than double the number of windstorm natural catastrophes, with particularly heavy losses as a result of Atlantic hurricanes.
The rise in natural catastrophe losses is primarily due to socio-economic factors. In many countries, populations are rising, and more and more people moving into exposed areas. At the same time, greater prosperity is leading to higher property values. Nevertheless, it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.
A related story by the Omaha World Herald, “So long, ‘500-year flood’?” explains:
As the Missouri River flood of 2011 unfolded, federal officials said the slow-motion disaster was caused by a once-in-500-year combination of rain and snow.
While some found comfort in that number, many who live along the river have seen too many big floods in too few years to trust that statistic.
They are on to something.
World-Herald interviews with experts show the bases of such terms as “500-year flood” are constantly evolving and increasingly questioned….
“As humans we are too tied to preparing for what we have observed or witnessed before. This year may not be as bad as it gets,” said Mark Anderson, director of the USGS South Dakota Water Science Center. “Much larger floods are possible, especially if we look beyond the historical record.”
… Like the USGS, the National Oceanic and Atmospheric Administration is noticing changes in the watershed that feeds the Missouri.
Anderson said a changing climate only compounds the shortcomings of using existing data to estimate the frequency of floods.
“If the climate is shifting, all those earlier records may not be as relevant today,” he said. “The point is, the future isn’t always a reflection of the past.”
How about “since”?
We ain’t seen nothing yet.