Climate change has thrown our beautifully balanced planet into chaos. As oceans and forests transform and ecosystems go into shock, perhaps a million species teeter on the edge of extinction. But there may still be hope for these organisms. Some will change their behaviors in response to soaring global temperatures; they might, say, reproduce earlier in the year, when it’s cooler. Others may even evolve to cope—perhaps by shrinking, because smaller frames lose heat more quickly.

For the moment, though, scientists have little idea how these adaptations may be playing out. A new paper in Nature Communications, coauthored by more than 60 researchers, aims to bring a measure of clarity. By sifting through 10,000 previous studies, the researchers found that the climatic chaos we’ve sowed may just be too intense [Editor’s note: The researchers scanned 10,000 abstracts, but their analysis is based on data from 58 studies]. Some species seem to be adapting, yes, but they aren’t doing so fast enough. That spells, in a word, doom.

To determine how a species is adjusting to a climate gone mad, you typically look at two things: morphology and phenology. Morphology refers to physiological changes, like the aforementioned shrinking effect; phenology has to do with the timing of life events such as breeding and migration. The bulk of the existing research concerns phenology.

The species in the new study skew avian, in large part because birds are relatively easy to observe. Researchers can set up nesting boxes, for instance, which allow them to log when adults lay eggs, when chicks hatch, how big the chicks are, and so on. And they can map how this is all changing as the climate warms.

By looking at these kinds of studies together, the authors of the Nature Communications paper found that the 17 bird species they examined seem to be shifting their phenology. “Birds in the Northern Hemisphere do show adaptive responses on average, though these adaptive responses are not sufficient in order for populations to persist in the long term,” says lead author Viktoriia Radchuk of the Leibniz Institute for Zoo and Wildlife Research.

In other words, the birds simply can’t keep up. By laying their eggs earlier, they’re encouraging their chicks to hatch when there are lots of insects to eat, which happens once temperatures rise in spring. But they’re not shifting quickly enough.

This isn’t a phenomenon exclusive to human-caused climate change. Life on Earth is so diverse because it’s so adaptable: temperatures go up or down, and a species might move into a new habitat and evolve to become something different over time. But what we humans have unleashed on this planet is unparalleled. “We’re experiencing something on the order of 1,000 times faster change in temperature than what was seen in paleo times,” says Radchuk. “There are limits to these adaptive responses, and the lag is getting too big.”

Which means now more than ever, we have to aggressively conserve habitats to help boost species. “I think the results of this paper really add an abundance of caution, that we shouldn’t hope that species will adapt to changing climate and changing habitats, that we don’t need to do anything,” says Mark Reynolds, lead scientist for the Nature Conservancy’s migratory bird program, who wasn’t involved in the study.

Indeed, this paper is a terrifying window into what might be happening to ecosystems at large. A bird doesn’t live in a vacuum—it preys and is preyed upon. An ecosystem is unfathomably complex, all sorts of creatures interacting, which makes these dynamics extremely difficult to study, especially when Earth’s climate is changing so quickly.

“It’s not an Internet type of network, it’s not an electrical grid,” says Peter Roopnarine, curator of geology and paleontology at the California Academy of Sciences, who wasn’t involved in this work. “These are systems that have very specific structures and configurations to them. We have poor documentation of that.”

On a very basic level, if insects start breeding earlier in the year because the planet is warming, birds have to shift their life cycles. That means the birds’ predators do, too. “One phenological change in one species can have a ripple effect through the system,” says Roopnarine.

Another major consideration here is generation length. Species that more rapidly produce offspring tend to adapt better to change. That’s why bacteria can so quickly evolve resistance to antibiotics: they proliferate like mad, and individual bacteria with the lucky genetics to survive the drugs win out and pass those genes along. Something like an elephant, which may not reproduce until she’s 20 years into a 50-year lifespan, is working with way longer timescales and may struggle to adapt to change.

What’s so troubling about this study is that, by comparison to other animal families, birds are relatively adaptable in their phenology: they can tweak the timing of their migrations, for instance. A less mobile critter like a frog has no such luxury. But what these researchers have found is that flexibility is no longer enough for salvation.

This story originally appeared on wired.com.

https://arstechnica.com/?p=1542205