A new White House strategy to combat biological threats issues a stark warning about infectious disease. But it fails to mention the many ways they can be influenced by climate change.
The National Biodefense Strategy unveiled yesterday outlines the federal approach to preventing, mitigating and recovering from disease outbreaks and other biological incidents. These events might occur naturally, through the result of laboratory accidents or as a biological terrorist attack.
“Biological threats emanate from many sources, and they know no borders,” President Trump said yesterday in a statement. “They have great potential to disrupt the economy, exact a toll on human life, and tear at the very fabric of society. My Administration will take steps to improve our understanding of the risks posed by biological threats and to respond to them effectively and efficiently.”
The new strategy emphasizes the importance of understanding the origins of biological dangers and preventing them as much as possible. It outlines a number of focus areas, including threats from drug-resistant pathogens, agricultural diseases and food-borne illnesses, laboratory accidents, and biological warfare. But despite acknowledging many specific events that can increase the risk of infectious disease, it makes no mention of climate change.
At a press briefing yesterday by national security adviser John Bolton and Secretary of Health and Human Services Alex Azar, neither official raised the topic of global warming.
Yet numerous scientists and infectious disease experts have warned in recent years that climate change could increase the risk of disease outbreaks in some locations.
Research suggests that warming may allow certain disease-carrying insects, such as mosquitoes and ticks, to expand into new areas. Multiple studies in recent years have attempted to project those changes in the U.S. for the coming decades. A 2016 study in Climatic Change, for instance, found that the mosquito species that carries Zika, chikungunya and dengue fever, among other diseases, may expand its global range by 13 percent under a severe climate change scenario.
Other research suggests that mosquitoes and other disease-carrying pests are already invading new areas. The exact links to climate change are not always clear, and other factors, such as human development, may also be playing a role. But many experts say that warming is probably an influence.
Last year, a report from the Centers for Disease Control and Prevention found that the two primary disease-carrying species of mosquito can now survive in more than three-quarters of all U.S. counties, based on climate variables like temperature and precipitation. And in May, another CDC report found that diseases carried by mosquitoes, fleas and ticks had tripled in the U.S. over the past 15 years (Climatewire, May 2).
Insects aren’t the only worry. The CDC warns that flooding also increases the risk of water-borne diseases, including everything from E. coli contamination to the bacterial disease Leptospirosis. Climate change is likely to increase the risk of flooding in many places, either through sea-level rise or an increased frequency in extreme rainfall events.
And other research suggests that tropical parasites, typically found in the global South, may start to become more prevalent in North America as the climate continues to warm. Chagas’ disease, spread by a parasite commonly known as the “kissing bug,” affects millions of people in Central and South America. It’s been known to be locally acquired in the U.S. on rare occasions—so far. But some experts have suggested that as the climate warms, Chagas-spreading parasites could start migrating farther north.
The factors affecting the spread of infectious disease tend to be complex. In addition to climate change, other forms of environmental change—such as deforestation or urbanization—may also affect the likelihood that humans could come into contact with disease-carrying pests or animals. Other aspects of human societies, including poverty, sanitation or access to clean water, can also affect the spread of disease.
Climate change is by no means the only concern, or even necessarily the biggest one, when it comes to infectious disease. But it’s certainly one of them, scientists increasingly warn.
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.