Posted: 4:35 pm Tuesday, July 10th, 2012
By John Nelander
On a statewide basis, Florida had the wettest June on record. (Credit: NOAA/ NCDC)
For the second month in a row, another consecutive 12-month temperature record was set in the U.S., according to the National Climatic Data Center.
The period from July 2011 through June 2012 was the warmest year-long period since record keeping began in 1895, with a national average temperature of 56.0, or 3.2 degrees above the long-term average. That’s also 0.05 degrees warmer than the last 12-month record from June 2011 through May 2012.
Every state in the lower 48 had above average temperatures except Washington, where temperatures were near normal.
Also, the January-June six-month period was the warmest first half of any year on record in the U.S.
Thanks to Tropical Storm Debby, June was the wettest on record in Florida overall, although much of that was focused in the Big Bend area and the eastern panhandle.
Some might be tempted to conclude that this is global warming finally coming home to roost. But researchers say there’s not enough evidence to make that assumption.
“This is always the million-dollar question, but unfortunately, there’s no definitive way to answer it,” says Steve Vavrus, a senior scientist in the Nelson Institute Center for Climatic Research at the University of Wisconsin-Madison.
“We’ve experienced extreme heat, drought, floods, wildfires and windstorms throughout history, so in a sense this is nothing unusual. We need time to assess whether this year’s set of extreme weather events falls outside of normal variations.”
There’s science, and then there’s gut feeling. And Varvus told a university interviewer: “I think it’s a harbinger of what’s to come under greenhouse warming. Virtually all climate models simulate more intense and frequent heat waves as the climate warms, and most of the world has experienced increases in extreme heat during the past several decades.”
One impact of the hot spell the climate has entered — whether you’re convinced it’s due to global warming with human intervention or believe it’s more of a natural phenomenon — is air quality. Air quality has been taking a hit across the country this summer, according to another University of Wisconsin researcher, Tracey Holloway.
June was particularly bad, she said. “In the last week of June, moderate or unhealthy air covered a third to half of the continental U.S.”
Air quality was an issue earlier this month as well. Trouble spots included, since July 1, coastal Delaware and New Jersey as well as parts of Tennessee and the Ohio Valley. These areas were marked Unsafe for Sensitive Groups, one step below Unhealthy, by AirNow, a consortium of air quality experts with the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA).
By the end of the Eastern U.S. heat wave last Friday, more unsafe areas sprouted up near Washington, D.C., Detroit, Mich., Chicago and Milwaukee, and Atlanta. A few Moderate readings were creeping into South and Central Florida.
The definition of Moderate pollution: ”Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.”
By Sunday, air quality readings had returned to the “Good” range throughout most of Florida and the Northeastern U.S.
The air quality index is based on the presence five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide.
About the Author
John Nelander is a freelance writer, book editor and publisher in West Palm Beach. Weather Matters features news and observations about the weather with a focus on what's happening in South Florida. The blog also looks at the latest studies on climate change as well as what's happening in the weather forecasting biz. His website is www.pbeditorialservices.com.