Year 2050

Get Ready for More Mosquitoes and Ants Thanks to Climate Change

An expert explains how the world's insect population will change by 2050.

by Mike Pearl
30 March 2017, 9:30pm

Illustration by Corey Brickley

This story is part of VICE's ongoing look at how climate change will have altered the world by the year 2050. Read more about the project here.

Bugs are everywhere—you're surrounded by them right now, wherever you are, and as the news is always eager to remind us, they could team up to destroy us at any moment they wanted. Insect species make up an estimated 80 percent of all species on Earth, and an estimated 80 percent of plants rely on insects to help them reproduce. Humans, in turn, would starve without those plants. So when you wonder how insects will be affected by climate change, what you're really asking is how everything will be

In fact, we're already experiencing the effects of climate change via bugs in surprising (and potentially catastrophic) ways. Last summer in California unusual levels of fire danger, at least partly because rising temperatures force certain native beetles into different environments, and the trees in those environments that can't handle beetles die by the thousands. When a forest has thousands of dead trees just chillin, without having fallen over yet, that forest becomes a tinderbox.

Though we might not immediately notice how climate change is affecting bugs, and how that in turn will affect us, by 2050 our world will be subtly altered. There's mundane stuff, like potato bugs showing up earlier in the year, which could lead to problems with farming, alongside really scary consequences like increases in diseases spread by the ticks and mosquitoes that will start wandering outside their normal habitats. There will also be fallout due to increases in invasive wasps, certain butterflies, and crop-destroying aphids. One upside to climate change? We'll have fewer fruit flies to deal with.

As for spiders—which are colloquially "bugs" though not insects—those are already cropping up in new places, and climate change is getting blamed. Horrifyingly, some research indicates that at least one species of already very large spider will get even larger, though some species will get smaller.

To get a sense of what the larger trends are, I called up Clint Penick, an integrative biologist who performs climate change experiments on the local insects at North Carolina State University and the North Carolina Museum of Natural Sciences. Penick told me what bug-related patterns are emerging in the next three decades thanks to climate change. Most of them don't sound very fun.

VICE: How will climate change hit bugs by the year 2050?
Clint Penick: It's hard to say a blanket statement about how climate change is impacting insects. For one, it's just that the sheer number of insect species on Earth [is too high]. There's been over a million species of insects described, and to understand how the bulk of the species respond to something as complex as climate change is a challenge, and it's impossible with the amount of time, and the amount of researchers that are working on these.

OK I'll narrow it down: Will any bugs be physically different in the next few decades?
We've been studying the 17-year cicadas—really long-living insects that live in rural areas and cities. One thing that happens with a lot of insects is that they just grow bigger when it's warmer. So, we're actually finding changes in cicada size with urban warming. You could predict something similar might be happening as we have climate change, we might get bigger cicadas.

Will any bugs die off?
The main thing that people have looked at is called the "critical thermal maximum." That's really just the temperature at which a species goes into heatstroke. Humans get to a certain temperature go into heat stroke, and the same thing goes for insects. You can measure the temperature that an insect gets heat stroke for a whole bunch of species, and then make broad generalizations about how they might be impacted by warming. Unsurprisingly, there are species that can tolerate warmer temperatures, and they tend to do better in climate change.

Could you tell me about some of those sweeping generalizations?
What we think will happen—and what is happening already—is that when it gets warmer, a species that can't tolerate the heat will either move north, or it's going to move up the slope of the mountain, where it's cooler.

Watch: The hidden effects of climate change

Makes sense. But what about bugs that already live in northern climates?
The species of bugs in northern areas can actually tolerate pretty broad temperature span. Because they experience really big swings in the north, it gets pretty hot in the north, then really cold in the winter, they can tolerate wide spans. But, if you go to a warm place like Florida, the average bug you pick up on the street can't even tolerate the same breadth of temperature change. If you look at the tropics, there's also much less room for species to migrate. So in an area like the eastern United States, there's a lot of room for species to move up the mountains that are in lowland areas or ways to move further north.

So possibly more bugs at higher altitudes, and higher latitudes. But what about heat-intolerant bugs who can't escape?
So if you go to a place like Costa Rica, where they don't really have very much room to move, and it turns out they can't tolerate temperatures that are much higher than what they're already living in. So, that's one of the big things that we're having to deal with. Everyone originally predicted that northern species were going to be at risk, but [in] tropical areas, the species that live there don't really have anywhere to go.

Aren't there bugs already living at the tops of mountains that are fucked too?
Yes, exactly. If you're a species that really can't take very warm temperatures and you're at the top of a mountain already, and now you have all these other migrants in your territories, you're going to get knocked off.

Let's get specific. What are some bugs who will move around in the next few decades?
In the Smoky Mountains, for instance, there's a warm-tolerating species of ant that's moving it's way up the mountain over the last couple decades. So these things are already happening on a small scale.

What about the bugs around our houses?
Good question. So down here in the South, everyone hates fire ants. They were about at their northern limit here in North Carolina—so they're limited by heat. In a warmer world, you would predict that fire ants are going to go a little bit more north, whether that's ten miles or a hundred miles north. [So] some people that were just out of the range to find fire ants might find that in the next decade or so that they have fire ants in their yard.

Can we say anything about the bugs living north of the Mason-Dixon Line?
You could expect things like the odorous house ant—which is the species that's on kitchen countertops especially in New York—to come out sooner. But I don't know if we can say too much about how warming is going to affect them. For one thing, if they're living in your house and you have A/C, the environment they experience is going to be a little bit different than it is outside.

In your area, what effects have you studied that don't involve ants?
The bulk of all the other insects after you remove ants are these things called fungus gnats.

I know the bastards very well. What about them?
They were the most abundant insect outside of ants in our study, and they [experienced] the strongest negative impact from warming, particularly in spring.

Should I care? Gnats suck.
[I] started to read through old literature about what fungus gnats do, what we know about their biology, and almost nothing is known about them. I think that's one of the craziest things we find with insects: [They] could be spore-dispersers, they could really be doing important things but we don't know.

Ah, so you're going to tell me that even the loss of an annoying insect has an unpredictable butterfly effect, right? Like when Homer Simpson goes back in time?
That's what we talk about a lot! Like this wildflower, trillium: Their seeds actually have a little thing stuck to them that's ant food. They eat that part of the seed, then chuck the seed somewhere far once they eat it. There's mutualism between ants and these wildflower species in eastern forests. And that's going to get broken, potentially.

The 800-pound gorilla in the room here here is disease-carrying insects. I recall there being warnings about an increase in malaria because the climate will be better for mosquitoes, but there's been a decline in malaria instead.
It doesn't have to do with the mosquitoes moving. It has to do with aid.

Could we still see more malaria in the near future because of mosquitoes?
One example I think you might look into is in Ethiopia. to escape disease, what a lot of people do is just move to the top of a mountain where it's too cold for mosquitoes. So people built larger communities on tops of mountains, and they had lower malaria rates. So now you have deep human populations, and now that mosquitoes are starting to move up to the tops of mountains with warming temperatures, they're at new risk with malaria due to climate change.

This conversation has been edited and condensed for length and clarity.

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