RIPTON — After 20 years of warnings from climate scientists, environmentalists and Al Gore, many would argue that the predicted consequences of global warming are being realized.
But whether or not a person believes that fossil fuels and deforestation have created a greenhouse effect that has increased temperatures on the earth by one degree so far, the fact that the climate is improving for mosquitoes is undeniable. And, two recent human cases of mosquito-borne Eastern equine encephalitis in the area have upped the ante and brought the issue to the backyards of Addison County and Brandon.
For renowned environmentalist and educator Bill McKibben it’s sobering to watch his predictions come to pass. The author of the very first book on global warming, “The End of Nature” in 1989, and more recently a “The Global Warming Reader,” said in a phone interview Monday that combatting arboviruses like EEE and West Nile virus carried by mosquitoes is the new reality.
“It’s the new world, in a sense,” the Ripton resident said. “Often, no one wants to believe this stuff is true, but this is it — mosquitoes like wet, warm places.”
The one species of mosquito that carries the EEE virus, the Culiseta melanura, has traditionally been found farther south along the Eastern seaboard in Florida, Louisiana and Georgia. But it has steadily moved north; it was first found in Massachusetts as far back as the 1930s. According to Erica Berl of the Vermont Health Department, after that, EEE cases would emerge in the Bay State for a decade, then disappear for years at a time. Then cases of the disease were diagnosed more frequently.
“Something has changed over the last decade,” she said at a meeting at Middlebury College last week. “Now, we’re finding it every year.”
Climate scientists predicted that as the earth’s temperature rises due to the greenhouse gas effect, there would be an increase in extreme weather, more flooding due to increased torrential rainfall, and milder winters and fewer hard frosts. Those conditions have been seen in Vermont over the last decade, making the evolution of deadly mosquito-borne illnesses like EEE and West Nile virus a given.
This has been a record year for West Nile virus in Texas, with 1,276 cases and 58 deaths from the disease so far.
Many would argue that this part of Vermont has been battling a mosquito problem for decades, and that global warming has nothing to do with it. But it’s hard to explain why, according to state entomologist Alan Graham, there were 20 species of mosquitoes in Vermont 20 years ago, and now there are 45.
Harsh winters and cold autumns with hard frosts can be relied on to kill off mosquito larvae laying in wait for the spring. Without that cold weather, the larvae live to hatch and bite another day, by the thousands.
McKibben said from the outside looking in, we’ve created the perfect mosquito habitat.
“If you’re looking at our galaxy through a telescope, a reasonable observer would assume that we’ve embarked on a mosquito farming initiative,” he said. “And the odds go up.”
McKibben said just as the chance of floods increases with the amount of rainfall, so do the odds of arboviruses hitting the human populations in record numbers.
“I wish I could say it just comes out of the blue, because it’s easier to deal with,” he said. “But this kind of thing does have a rhyme and a reason.”
And, McKibben pointed out, it’s not just mosquitoes we are fighting, but an explosion in the tick population as well. The number of cases of Lyme disease, a debilitating tick-borne illness, has skyrocketed in the state.
According to the Vermont Department of Health, the number of confirmed Lyme disease cases in Vermont rose from 40 annually to more than 500 a year between 2000 and 2011.
McKibben also said that the real cost of using fossil fuels can also be figured into the call for increased funding to combat mosquitoes and ticks.
“When people talk about the cost of climate change, we don’t figure in all of the other costs to figure just how expensive gas is,” he said. “We have a lot of other things we’d rather do like educate kids and heal sick people and it’s a great shame because we were careless with fossil fuels.”
Ultimately, McKibben said, it is human nature to adapt and we are, whether it means building better to combat future floods, covering our bare skin when we go outside, or applying bug spray to avoid EEE.
“But it’s not the same,” he said. “One thing we lose is the carefree sense of the world around us. In Vermont, we thought we had refuge from many of these things because of the cold. We’ve lost a lot of that protection, and we will lose more.”