Meet the Aedes aegypti mosquito.
Actually, you don’t want to meet this little lady, who bites for blood that she needs to mature her eggs.
The Aedes aegypti spreads dengue fever, which affects about 100 million people a year. Most are in tropical and subtropical regions–South and Central America, southeast Asia and Africa. Dengue fever is rare in the U.S. except along the border with Mexico.
That’s changing–in part because of climate change.
“The range of the mosquito that causes dengue is creeping upwards,” says Andrew Monaghan, a meteorologist at the National Center for Atmospheric Research (NCAR).
I’ve been meeting with scientists like Andrew this week as part of a journalism fellowship at NCAR, which is home to some of the world’s most prominent client scientists. They are delivering mostly–but not entirely–sobering news about the dangers of climate instability.
This idea that dengue fever is spreading into temperate climates isn’t new. In 2009, the National Resources Defense Council reported that “mosquitoes capable of transmitting dengue fever can now be found across at least 28 states.”
Nearly 4,000 cases of imported and locally transmitted dengue fever were reported in the United States by the Centers for Disease Control and Prevention between 1995 and 2005; if cases along the Texas-Mexico border area are included, that number rises to 10,000.
Andrew’s group at NCAR is now studying the habits of the mosquito more closely, particularly in Mexico. He is working with colleagues at the Center for Disease Control and NASA, as well as scientists in Mexico, to model the activity of the mosquito.
These mosquitos, it turns out, have odd habits. “They only breed near humans,” Andrew said. “For the most part, this is a very urban mosquito.” The mosquitos like to breed in tires and trash, so one way of preventing the spread of dengue fever would be better sanitation and trash pickup. Another, of course, would be to take the climate threat more seriously.
The good news: Dengue fever isn’t usually fatal, and for now it’s a minor problem most in the U.S. [Below is a 2009 map tracking its spread from the Centers for Disease Control.)
The bad news: The disease is very unpleasant–symptoms include severe headaches, rash and achy muscles that last about a week.
Stepping back a bit from dengue fever, it’s been estimated by the Climate Institute, a respected nonprofit, that “climate change contributes to 150,000 deaths and 5 million illnesses each year.” It’s hard to know exactly what that claim means–many other factors (the effectiveness of public health systems, education, income) besides climate affect disease, so isolating the impact of climate change is difficult. In a new book called Changing Planet, Changing Health., Dr. Paul Epstein of Harvard Medical School and journalist Dan Ferber argue that climate change is literally making us sick.
I know I have no interest in becoming lunch for the Aedes aegypti. It’s one more reason, not that we need one, to take the climate threat seriously.