Hot summers

Paul Newman and Joanne Woodward in The Long, Hot Summer [1958].

Here we go with a scare headline and words like "could be" and "might actually be". All you can derive from this is incomplete statistical data, wild speculation, and a weak cause and effect. We simply don't know the Earth's climate history to make objective statements about future climate conditions.

"Think this summer is hot? Get used to it"

by

Doyle Rice

August 11th, 2010

USA TODAY

This summer's stifling, deadly heat along the Eastern Seaboard and Deep South could be a preview of summers to come over the next few decades, according to a report about global warming to be published Wednesday by the National Wildlife Federation and the Asthma and Allergy Foundation of America.

In fact, according to NWF climate scientist Amanda Staudt, the summer of 2010 might actually be considered mild compared with the typical summers in the future. "We all think this summer is miserable, but it's nothing compared to what's in store for us," she says.

The East just sweltered through one of its hottest Julys on record, the National Oceanic and Atmospheric Administration reported Monday. Every state from Maine to Florida endured one its top-10 warmest Julys since records began in 1880. Two states, Delaware and Rhode Island, had their hottest July ever.

The report, a supplement to a 2009 report on heat waves, notes that more extremely hot summer days are projected for every part of the country by the year 2050: "Summers like the current one, or even worse, will become the norm by 2050 if global warming pollution continues to increase unabated."

A federal report by the U.S. Global Change Research Program in 2009, which much of this report was based on, found that average temperatures in the USA have increased more than 2 degrees Fahrenheit in the past five decades, largely as the result of emissions of heat-trapping greenhouse gases such as carbon dioxide, which are produced by burning fossil fuels.

But can this summer's heat be directly attributed to global warming?

Staudt concedes that it can't, as does Chris Fenimore, a physical scientist at the National Climatic Data Center, who was not part of the study: "It's not really possible to pin a single event on climate change."

However, Fenimore notes that the frequency at which these extreme weather events are occurring — such as extreme heat or cold — are on the increase.

"Most locations have had about twice as many days with temperatures exceeding 90 degrees than they typically would by the end of July," the NWF report states about this summer's heat. "For example, Washington, D.C., had 39 days with temperatures in the 90s by July 31, compared to 18 days for an average year."

Additional heat waves will be especially dangerous for vulnerable populations, Staudt says. "Air pollution in urban areas could get worse, bringing increased risk of heart attacks, strokes and asthma attacks. Children, the elderly, poor and people of color are especially vulnerable to these effects."

The report states that global warming could increase asthma-triggering ground-level ozone by 10 parts per billion or more during heat waves by 2050 in the Midwest and Northeast. "For a city like Washington, D.C., that means about 42 excess deaths for each day that there is elevated ozone," the report notes.

Now, about 4,000 to 5,000 Americans die each year because of asthma, says Mike Tringale of the Asthma and Allergy Foundation of America.