Weather Blog: The link between ticks, poison ivy and climate change

Reports of Lyme disease have doubled over the past two decades. Is climate change to blame?
Is a warming climate leading to more ticks and more toxic poison ivy? Find out in this week's...
Is a warming climate leading to more ticks and more toxic poison ivy? Find out in this week's weather blog.(WRDW)
Published: Aug. 19, 2020 at 11:03 AM EDT|Updated: Aug. 19, 2020 at 3:49 PM EDT
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AUGUSTA, Ga. (WRDW/WAGT) - While scientists are confident that being outside reduces the risk of transmitting COVID-19 there are still some threats to be aware while you are spending time in the great outdoors. Among those threats are ticks and poison ivy. The bad news is that both of them may be getting worse due to climate change. Graphics courtesy of Climate Central.

Warmer average temperatures in between January and May since 1970 have made conditions more...
Warmer average temperatures in between January and May since 1970 have made conditions more favorable for ticks.(WRDW)

Rising temperatures are associated with faster tick development and population growth which allows ticks to become active earlier in the year and spread to areas that were once too cold for them to inhabit.

Lyme Disease has been on the rise in the U.S. for most years since 1996.
Lyme Disease has been on the rise in the U.S. for most years since 1996.(WRDW)

Reports of Lyme disease have doubled over the past two decades to upwards of 30,000 cases per year. The disease is primarily transmitted by the “blacklegged tick” also known as the “deer tick”, which is native to the Central Savannah River Area (CSRA). This significant uptrend is a result of multiple factors with one of the largest factors being our warming climate according to the Environmental Protection Agency (EPA). From ticks emerging earlier in the year to ticks multiplying faster, warming temperatures can cause changes in tick behavior that increase our risk of catching Lyme disease.

Source: Center for Disease Control
Source: Center for Disease Control(CDC)

A long-term study of the blacklegged tick in New York found that rising temperatures between January and May were associated with a peak in activity that was almost three weeks earlier for juvenile ticks. These ticks are the ones most likely to transmit Lyme disease. As temperatures warm, ticks are able to develop faster and emerge earlier. This does not necessarily mean that ticks will stick around longer but faster development could increase the odds of them surviving to adulthood which would also increase the rate at which they multiply and spread towards areas they are typically not found.

Poison Ivy has become more potent as a result of increases in CO2 levels since the 1950s.
Poison Ivy has become more potent as a result of increases in CO2 levels since the 1950s.(WRDW)

Another component of climate change is elevated levels of CO2. These elevated CO2 levels have been shown to stimulate the growth of larger and more toxic poison ivy plants. Note to self: the next time you’re dodging ticks on your next venture outdoors, don’t forget about poison ivy. CO2 levels have risen rapidly in recent decades which has already brought about a significant change in poison ivy plants. From around 1950 (300 ppm) to today (400 ppm), the increase in CO2 was associated with the surface area of poison ivy leaves more than doubling. The levels of toxic oil in poison ivy known as urushiol increased even more dramatically (by 173%) in the same period.

While many species struggle to adapt with a changing climate and conditions, pests and weeds unfortunately find a way to thrive which ultimately causes overall biodiversity to suffer. In order to maintain the healthiest ecosystems and societies possible for human life, we must slow down widespread temperature change and work towards stabilizing our climate by lowering greenhouse gas emissions.

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