Global warming is spurring epic drought, irreversible sea level rise, and record-breaking wildfires, sure—but it's also rewiring our biosphere in much less visible and more complex ways. Like, it's turning bugs white.
A new study published in Nature Communications reveals that insect populations across Europe are being whitewashed. Darker-colored butterflies and dragonflies are losing out to their lighter-colored counterparts, which are thriving in hotter climes.
As with reptiles, the color of an insect largely determines how they absorb energy from the sun—darker bugs can absorb more of it, in order to increase their body temperatures. In hotter locales, insects need to stave off overheating, and would rather absorb less solar energy; the lighter colors bounce the sunlight off their insectoid bodies and wings.
New research, led by Imperial College London's Professor Carsten Rahbek, examined the distribution of 473 butterfly and dragonfly populations, and determined that a mass shift in insect color is underway.
“For two of the major groups of insects, we have now demonstrated a direct link between climate and insect colour, which impact their geographical distribution,” Rahbek said in a statement. "We now know that lighter-coloured butterflies and dragonflies are doing better in a warmer world, and we have also demonstrated that the effects of climate change on where species live are not something of the future, but that nature and its ecosystems are changing as we speak."
Warming climes are driving darker bugs north, into smaller and smaller territories, and lighter bugs are on the rise; the white Dainty Damselfly was spotted in England in 2010 for the first time in 50 years.
The finding is another reminder of the profound ecological transformations climate change is initiating around the world; I'm not sure I'd describe it as the "end of nature," as Bill McKibben did in his early, influential, and prescient 1990 book of the same name. But his point stands—the carbon humankind burned for power is now influencing just about every iota of the wild—it's making the oceans just acidic enough to dissolve sea snails' shells. It's shrinking mammals.
And it's changing the color of insect populations. What impact might that actually have on insect species worldwide? As always, it's almost impossible to say. There could be knock-on effects; the lighter insects could be more vulnerable to certain predators, or, conversely, could risk overabundance. We just won't know for sure until the rise of the light bugs is complete.