Animals Are Getting Smaller as the Planet Warms

One of the many effects of human-driven climate change is that, on average, the bodies of animals are getting smaller — birds, fish, deer, frogs, rodents, insects. And these changes could have large and unpredictable consequences.

“That’s the problem with human-driven climate change. It’s the rate of change that’s just orders of magnitude faster than what the natural world has had to deal with in the past. Size is really important to survival, and you can’t just change that indefinitely without consequence. For one thing, I don’t think it’s feasible that species are going to be able to continue to get smaller and maintain things like a migration from one hemisphere to another.”

And since smaller bodies can hold fewer eggs, they result in fewer offspring, and a lower population size in the long run. For amphibians who need to keep their skin wet in order to breathe, shrinking can mean higher chances of drying out in a drought because their bodies absorb and hold smaller quantities of water.

But the more concerning consequences have to do with how this could destabilize relationships between species. Because shrinking plays out at different rates for different species, predators might have to eat more and more of shrinking prey, for example, throwing a finely-tuned ecosystem off balance.

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