Scientists give a grim warning on climate change and insect populations

I talk a lot about the need for a climate response that’s centered around ecosystem resilience. Our best defense against the existential crises that face us is to not only stop the destruction of ecosystems, but also to actively work to build them up. The problem is, the longer we take to accomplish the first half of that plan, the harder it will be to carry out the second half. We have a much, much better chance of success if we’re helping struggling, but extant ecosystems survive, than if we’re trying to build up new ones from what’s left after total collapse.

The problem is, we seem to be getting pretty close to the “total collapse” stage. Even without climate change, ecosystems around the world are suffering from chemical pollution, and for a while now pesticides have been the prime suspect in the ongoing decline in insects (PZ did a good post on that recently). We’ve always known that climate change would be rough for many insect species, but it now we’ve got a pretty stark warning. 70 entimologists have cosigned a letter warning that climate change threatens to push us into the “total collapse” scenario, through its effects on insects alone:

In a new scientific review, a team of 70 scientists from 19 countries warned that if no steps are taken to shield insects from the consequences of climate change, it will “drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems.”

Citing research from around the world, the team painted a bleak picture of the short- and long-term effects of climate change on insects, many of which have been in a state of decline for decades. Global warming and extreme weather events are already threatening some insects with extinction—and it will only get worse if current trends continue, scientists say. Some insects will be forced to move to cooler climes to survive, while others will face impacts to their fertility, life cycle and interactions with other species.

Such drastic disruptions to ecosystems could ultimately come back to bite people, explained Anahí Espíndola, an assistant professor of entomology at the University of Maryland and one of the paper’s co-authors.

“We need to realize, as humans, that we are one species out of millions of species, and there’s no reason for us to assume that we’re never going to go extinct,” Espíndola said. “These changes to insects can affect our species in pretty drastic ways.”

Bees are probably the most well-known example of this right now, as they’re famous as pollinators, but there are many other insects that not only pollinate plants, but do a variety of things that, as part of a health ecosystem, make our own lives possible. As the paper explains, the process of responding to climate change as a population – range shifts, body changes, and behavior changes – is one that by necessity puts a strain on those populations, and makes them more vulnerable. Unfortunately, the other well-known problem with climate change and bugs is that some species seem to be fine with the change, and because we cannot catch a break, those seem to be the ones that cause us problems:

On the other hand, climate change may make some insects more pervasive—to the detriment of human health and agriculture. Global warming is expected to expand the geographical range of some disease vectors (such as mosquitoes) and crop-eating pests.

“Many pests are actually pretty generalist, so that means they are able to feed on many different types of plants,” Espíndola said. “And those are the insects that—based on the data—seem to be the least negatively affected by climate change.”

The concern about crop-eating pests is a small part of why I lean so hard on the idea of moving food production indoors. We’ll have enough trouble dealing with war, drought, heat, floods, and so on, without adding in more locust swarms. An added benefit of that would be less exposure to mosquitoes, ticks and the like for farm workers, and less exposure to, and use of pesticides.

When I have bad news to share – which seems like most days – I try to redirect focus to ways people can do something about the systemic problems dragging us towards extinction, and thankfully the authors of this warning do have a pretty clear action plan:

Though these effects are already being felt by insects, it is not too late to take action. The paper outlined steps that policymakers and the public can take to protect insects and their habitats. Scientists recommended “transformative action” in six areas: phasing out fossil fuels, curbing air pollutants, restoring and permanently protecting ecosystems, promoting mostly plant-based diets, moving towards a circular economy and stabilizing the global human population.

The paper’s lead author, Jeffrey Harvey of the Netherlands Institute of Ecology (NIOO-KNAW) and Vrije Universiteit Amsterdam, said in a statement that urgent action is needed to protect insects and the ecosystems they support.

“Insects are tough little critters, and we should be relieved that there is still room to correct our mistakes,” Harvey said. “We really need to enact policies to stabilize the global climate. In the meantime, at both government and individual levels, we can all pitch in and make urban and rural landscapes more insect-friendly.”

The paper suggested ways that individuals can help, including managing public, private or urban gardens and other green spaces in a more ecologically-friendly way—for instance, incorporating native plants into the mix and avoiding pesticides and significant changes in land usage when possible.

Espíndola also stressed the value of encouraging neighbors, friends and family to take similar steps, explaining that it’s an easy yet effective way to amplify one’s impact.

“It is true that these small actions are very powerful,” Espíndola said. “They are even more powerful when they are not isolated.”

As with the rest of our environmental problems, while it’s good to know how we can work to fix them, that knowledge will not help us without building the power for political change. Do what you can – I’m actually going to set up that pollinator garden this spring – but part of helping save the insects (and ourselves) is building collective power, so that we can create revolutionary systemic change.

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  1. Alan G. Humphrey says

    I live in the high desert of New Mexico and the recent road building and upgrades have added a lot of native plants in a xeriscape, both in the expanded medians and areas between the road and sidewalk, which shows that the city recognizes the need. The problem I have seen on my walks is that too many of these plants are pollinator attracting and the traffic moves at 35 to 45 MPH, if they follow the speed limits, which we know they do not. The flowering trees and shrubs in the medians especially are worrying because bees will have to cross through the traffic to get to those flowers. I wonder why the whole local environment is still not considered in these decisions. It is almost as if those making the decisions don’t actually ever walk along the sidewalks, among the plants, smelling the flowers, tasting the edible ones (always check for bees) and observing the wildlife and traffic they designed into conflict.

  2. Katydid says

    I’ve lived in the sae house for a number of years, and this year I saw practically zero bees. I have 1/2 acre of land including several perennial flower beds and every year I plant organic annuals. My neighbors all spray their lawns for weeds, mosquitoes, etc. Wondering if that’s why I’m not seeing the bees. Come to think of it, I didn’t see any butterflies, either.

    However, I’ve been raking leaves for the past couple of days and I can tell you, there are so many stinging and biting insects still out there.

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