We’ve Got A Fever, And The Only Prescription Is Less Climate Change

from Wildlife Promise

Discover Magazine’s cover story for the month of December—which I received yesterday, presumably because I’m some kind of fancy postal service VIP—feels like a Halloween holdover. Scary CGI mosquito, backlit by a harsh, unyielding sun, globe swathed in shadow; the story: How We’ll Stop The Coming Plague.

I like Discover because it talks science in non-science terms so nimrods like yours truly can understand it. This story is a fine example of that tradition, a survey of some of the public health scourges expected to expand and intensify as climate change worsens in the coming decades. The focus is on tropical diseases. (No link available yet, so I transcribed some relevant passages for you like a moron.)

“Climate change will cause a worsening of common health problems we already see,” says John Balbus, senior adviser for public health at the National Institute for Environmental Health Sciences. “There will be incremental changes in the next 5 to 10 years, but that might not compare to what we’re going to see in a matter of decades. In trying not to be alarmist, scientists have systematically underestimated the threat.”

“Climate change is the biggest global health threat of the 21st century,” a team of British scientists and academics wrote in The Lancet  (Ed: Link here subscription required) last year. The threat has been completely neglected, marginalized, and ignored by global health community and by policymakers, according to pediatrician Anthony Costello, director of University College London’s Institute for Global Health and lead author of the report. “Yet in terms of our well-being, in terms of our survival over the next 100 years, it is absolutely the top political issue involving the ecosystem that we should be talking about,” he adds.

Among other things, the story finds more serious forms of dengue fever, usually a tropical disease, “roaring back” in the United States, probably partly due to the spread of climatic conditions hospitable to the catalyst virus’s number one vector, the Asian tiger mosquito. Warmer winters have allowed the adults and larvae to flourish in places where the first cold snap would once have wreaked havoc on the entire population. According to the Natural Resources Defense Council (NRDC), dengue-carrying mosquitoes are spreading into formerly off-limits temperate areas, some as far north as New York and New Hampshire.

From the NRDC report on mosquitoes and dengue fever (PDF):

Global warming is projected to increase the amount and variability of precipitation in many areas, which can create expanded habitat hospitable to immature mosquitoes. Higher humidity contributes to improved survival of eggs and adult mosquitoes. Drought can also lead to increased transmission in cities without adequate water and sanitation, because people store drinking water in containers that can serve as mosquito breeding sites. Finally, global warming can enhance the frequency and intensity of extreme weather events that are likely to disrupt shelter, water, sewer, and sanitation services. If window and door screens are damaged, human-mosquito contact will increase; if drinking water supplies are disrupted, people will be forced to store water in containers, leaving local populations even more vulnerable as floodwaters recede.

No wonder those little schmucks were Discover’s cover fiends.

Discover again:

Hotter, more humid weather shortens mosquito breeding cycles. Heat speeds up the incubation of the dengue virus, making it infectious much sooner and for more of the insect’s life span. Female mosquitoes bite more frequently when the thermostat rises [...]

Like so many horrifying climate change consequence analyses, it goes on and on and on.

Of course, dengue fever isn’t the only disease projected to become more prevalent as global warming marches on. Lyme disease, Rocky Mountain spotted fever, encephalitis, and other vector-borne diseases “are rapidly changing their distribution and frequency[.]“ For a little more on those with a ridiculous video to blunt the terror, see NWF’s “They Came From Climate Change” report from March.

See this guy? He actually doesn't mind global warming all that much. ( flickr | smccann )

The bottom line is that a warming climate and extreme weather patterns are projected to spread and exacerbate infectious diseases that have traditionally been confined to environmentally and climatically distinct parts of the world. Like so many climate change effects, threats like dengue fever would disproportionately affect the poor—those not living “hermetically sealed in [their] houses—with screens on the windows and air-conditioning.”

But climate change-spurred public health threats are not limited to those carried by heat-loving mosquitoes, ticks, and the like. Some folks will get sick the way they always have, albeit more intensely and frequently, from allergies and asthma. </breathes a non-congested sigh of relief, checks pants for ticks again>*

By most estimates, at least 50 million Americans already suffer from either asthma or allergies, and that number is going up. Increasing pollen, air pollution, and Ozone smog are among the main culprits, all tied to a warming climate.

(Remember when we talked about climate change/weeds/allergies last week? It really happened. )

An NWF report earlier this year found that unchecked global warming will ramp up respiratory allergies for about 25 million people in this country as “allergy triggers” worsen. Discover points out that new research shows warmer weather combined with higher emissions will actually make the pollen itself worse. USDA scientists  recently grew weeds at three different sites in my home state of Maryland (an organic farm, a suburban Baltimore park, and downtown Baltimore) and found that the urban weeds, benefiting from a smoggy, urban heat island habitat, grew to “nearly twice the size of plants on the farm” and generated more pollen which proved more allergenic.

And yet: even if you have no allergies and a foolproof tick- and mosquito-blocking plan, you’re not off the hook. Discover cites another NWF report, this one from last year, that projected more common (and more intense) heat waves as climate change worsens, especially in urban areas. That, too, would disproportionately affect the poor, elderly, infirm, and very young. More information on that here.

Peter Wilk, MD, executive director, Physicians for Social Responsibility, which partnered with NWF on the report:

The science confirms that the frequency and duration of heat waves has increased significantly over the last 50 years. In the United States, heat waves already kill more people during a typical year than floods, tornadoes and earthquakes combined. Given these worsening trends, taking decisive action to stop global warming becomes a medical necessity.

Key, that last point, and a response to Discover’s cover question–’how we’ll stop the coming plague.’

Anthony Costello, director of University College London’s Institute for Global Health:

“Current climate developments are at the very worst end of the computer model predictions,” he says. “Every year of delay increases the costs and difficulties of effective action.”

Sounds about right. For more on the public health challenges projected to emerge as climate change worsens, see the World Health Organization’s “climate change and human health” page or download their 2009 report on ‘protecting health from climate change.’

* – I found a tick in my pants after our staff paintball trip in August, so I assume ticks are pants-generated.