Ticks, Mosquitoes, and Climate Change

In the past two weeks I have removed two tiny embedded ticks from my five year old son. Due to their very small size I assumed they were deer ticks. The second tick had not begun to feed yet so my son was safe from Lyme Disease but the first tick was fully engorged. It takes about 24-36 hours for an embedded tick to transmit the disease according to health experts so the first tick was a concern. The pediatrician sent the tick to be tested and fortunately it was a Lone Star tick which does not carry Lyme nor any other chronic disease. There are many factors that influence deer tick and mosquito populations. Human-caused global warming is one such factor and is predicted to lead to more Lyme disease and West Nile virus.

The northeastern US has experienced higher temperatures (especially during winter) and increased precipitation since the 1970s. Furthermore, the precipitation pattern has shifted to more intense downpours. The pattern of warmer weather and more intense precipitation is likely to continue because humans are dumping ever increasing amounts of heat-trapping carbon dioxide into the air each year with little sign of a slowdown.

According to Responding to Climate Change in New York State (2011), “Temperatures are expected to rise across the state, by 1.5 to 3°F by the 2020s, 3 to 5.5°F by the 2050s, and 4 to 9°F by the 2080s. The lower ends of these ranges are for lower greenhouse gas emissions scenarios (in which society reduces heat-trapping emissions) and the higher ends for higher emissions scenarios (in which emissions continue to increase). These are not the best and worst cases, however. Sharp cuts in global emissions could result in temperature increases lower than the bottoms of these ranges, while a continuation of business-as-usual could result in increases higher than the high ends.” and “Continuing the observed trend, more precipitation is expected to fall in heavy downpours and less in light rains.”

Warmer winters allow more ticks to survive and also decrease the mortality of mice – a tick’s favorite food source. Interestingly enough, acorn numbers also play a role because fewer acorns means fewer mice for ticks to feed on. When that happens ticks are going to look to our pets and our family members for their blood meal.  Studies suggest that plants produce more seeds with warmer temperatures and higher levels of carbon dioxide and that means more acorns. More acorns means more mice and more hosts for deer ticks (Huffington Post, 2012).

Ticks are just one increasing health concern. According to one of the largest West Nile studies to date, “a single rainstorm resulting in at least two inches of rain could increase infection rates by 33 percent, while smaller storms did not. Heavy rainfall increases humidity, which can stimulate mosquitoes to bite; it also creates pools of water in which mosquitoes can breed.” These types of storms are on the increase and expected to become more frequent so experts predict increasing rates of West Nile infections.

So what can we do? Immediately we can protect our pets and our families from ticks and mosquitoes by following the advice from experts. The CDC has this tick prevention info card and About.com has a very good list of tick prevention measures. For West Nile prevention, I suggest viewing this CDC web page.

We must also reduce our carbon emissions to slow global warming. To do so the United States and the rest of the world must embrace energy efficiency and smarter uses of energy such as solar, wind, geothermal, and nuclear. Until the US takes the lead we cannot expect developing countries such as China and India (major carbon polluters) to also limit their emissions. If we adopt a national energy policy that is informed by the settled science of human-caused climate change and results in the reduced use of fossil fuels such as coal and oil, we will secure our public health. Adopting such a policy will also lead to greater national security and increased economic competitiveness as these new energy technologies create well-paying high-tech jobs.  

It is a win-win-win.