Poison Ivy Just Got Superpowers, Thanks to Climate Change

I was pregnant when poison oak first got me. Since I grew up in England, where stinging nettles are as bad as it gets, I had no idea what was going on.

But I woke up one morning with weeping blisters all over my arms, an oozing rash on my neck and what looked like a black eye, and my whole body felt maddeningly itchy. Worse still, my doctor forbade any kind of medication because of what it might to do my unborn child.

So yes, I am highly allergic to poison oak (and poison ivy and poison sumac, as it turned out), but then so are 80 percent of the population.

This means that the news that poison ivy plants are getting bigger and nastier due to climate change is unwelcome news to a whole lot of people. That’s right: climate change is not just heating up the oceans and creating extreme weather events, it’s also increasing your chances of getting a bad case of poison ivy or poison oak.

A study published in 2006 found that a rise in carbon dioxide both fueled the growth of these weeds and increased the potency of urushiol, the oil at the root of the rash. Poison oak and poison sumac also contain urushiol, and all three can cause the blistering rash, as many of us sufferers know.

More CO2 Means More Poison Ivy

From PBS:

That study involved planting PVC pipes into six plots of North Carolina’s 7,000-acre Duke Forest. Carbon dioxide was blown through holes in the pipes, which stretched to the tops of the tree canopies, while another control group of pipes vented normal air. Of all the plants, poison ivy was the hands-down winner, said Jacqueline Mohan, assistant professor at the University of Georgia and the study’s lead author.

“It was the most responsive species to the higher carbon dioxide in the atmosphere,” Mohan said. “The average little tree that I measured grew 8 percent faster. And poison ivy grew 149 percent faster than it would have under ambient, normal carbon dioxide conditions.”

Since this first study, two other reports have found that as the level of carbon dioxide in the atmosphere increases, it’s boosting the growth of poison ivy plants.

“Initial data suggests that there may be a more [powerful] form of urushiol being produced with increasing carbon dioxide,” says Lewis Ziska, PhD, a weed ecologist at the U.S. Department of Agriculture in Beltsville, Md., and a co-researcher of both studies.

Growth Rate of Poison Ivy Doubled in Last 50 Years

In the last 50 years, Ziska says, the growth rate of the poison ivy plant has doubled. “The chances of encountering poison ivy and coming down with a rash are greater than they used to be,” he tells WebMD.

At the very least, getting poison ivy or poison oak can doom you to a week or more of miserable itching. At the worst you will end up in the emergency room. Neither is a pleasant prospect.

One solution is to never venture outside. On a more reasonable note, here’s what you need to know before you head out to the woods, or even the backyard.

Preventative Measures

Knowing what the evil weed looks like, so that you can avoid it, is the best plan.”Leaves of three, let it be” is the motto repeated by the experts. Each leaf of the poison ivy and poison oak plant has three leaflets.

If you suspect you might be in a poison ivy area, there are over-the-counter products, such as Technu and IvyBlock that can be effective if applied before exposure. They create a physical barrier, so the oil can’t penetrate the skin. You can also try applying even after you have been exposed.

Wearing long pants and long-sleeve shirts, even in the summer heat, is also recommended, as well as wearing socks and shoes to garden.

And always take a long shower (not a bath) if you think you may have been exposed to these nasty weeds.

Now, can someone tell me what is the point of these plants?

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Photo Credit: Thinkstock


Carrie-Anne Brown

signed, thanks for sharing :)

Virginia B.
Virginia B4 years ago

P.S. UnfortunatelyI learned that the bare branches/twigs of p. -i. can pass on allergic reactions, too. My daughter came down with a bad case of p.i. allergic reaction, after cavorting as a little kid in the bare branches of a roadside patch of this plant during December, when no tell-tale leaves were there to warn us away!

Virginia B.
Virginia B4 years ago

A reader may already have added these comments, but just in case, here goes: not only does poison ivy have "leaves of three", but these leaves have a shiny, oily appearance (as well they should, since it is their oil which "gets'"us). The second fact: some of that oil can come off on one's clothes, so it is wise to put gloves on, before you remove your clothes, which have had contact with p.-i., and as you are putting them into the washer (hot soapy water recommended. Strange fact: horses seem unfazed by eating the stuff, as they often "snacked on" p.-i. as we rode them through our p.-i. -infested woods.

Jasmine Summers-Evans


Bruno Moreira
Bruno Moreira4 years ago

Oh well interesting I do not know that. Like this I guess we're always learning every single day of our lives

Lindsey O.
Lindsey O4 years ago

It's poison ivy the author is discussing with relation to allergies, Nikolas. And for that it is a matter of an allergic reaction. Not everyone has the allergy but the majority of us unfortunately do.

Nikolas Karman
Nikolas K4 years ago

What a bull shit article. Plants all use carbon dioxide to grow and in return give us oxygen just look how green it is by the roadside compared to the adjoining paddocks and it has nothing to do with global warming which is just another fear mongering scam to raise /introduce more taxes for the banksters. I wonder just where they get these authors from who cant even understand how things really work like Osmosis for starters. Of coarse if you come in contact with stinging nettles your going to be stung so why be stupid and do so in the first place and just being stung has nothing to do with allergies. Hmmm i got hit by a car once so according to this writer I must be allergic to cars.

Sheila M.
Sheila M4 years ago

As a child I had horrible reactions to poison oak that would often keep me home from school with bleeding oozing sores. We camped a lot and spent most of our summers at my grandfather's "ranch" so it was really easy to come in contact with the plant. We would have to take off all our clothes when we came in from out doors and we took showers with
fels-naptha soap and then our clothes and bedding (if we had been camping) was washed in the laundry soap. I was sent to an allergy Doctor who had me drink drops of the urushiol oil that is in all three of the poison plants. Every summer for about three years I would drink 2 drops every morning for a week then 4 drops and so on until I was up to 32 drops. The first year I had only two very mild reactions to the poison oak then the second year I had one very slight case of poison oak. I have never had another reaction to any of the plants and over the years I have come in contact with all three depending what part of the country I have lived in. I have actually seen this remedy sold where homeopathic products are available.

Lindsey O.
Lindsey O4 years ago

I've had to live with the presence of poison ivy all my life (it flourishes here in the South.) And unlike the author I can't begin to remember my first itchy exposure to it (since it probably happened in babyhood - and continued at regular intervals throughout my life). It is a misery.

One other piece of good advice: never burn poison ivy plants, however tempting and easy a way it may seem to get rid of them. The smoke also contains the same poison particles - and can land you in the hospital from being exposed to it (as my mother found out when she unwisely burned a patch.) Burning them just spreads the poison farther and faster.

I'd imagine our superabundance of kudzu here in the South also loves global warming (though, of course, kudzu would thrive in any and all situations - it takes on all threatening environmental challenges with Luciferian glee....)

Jonathan Harper
Jonathan Harper4 years ago