How Caterpillars Are Contributing to Carbon Emissions

It's no secret that carbon emissions come from all sorts of places, from the meat industry to large production companies. But a recent study revealed another carbon source, and this one's got us quite surprised: caterpillars.

Researchers led by the University of Cambridge connected caterpillars to increased carbon after studying 32 years of water chemistry data from twelve lakes and their surrounding areas in Ontario, Canada. Their conclusion? Two aspects of the caterpillar's lifestyle lead to carbon emissions in their habitats: the insects' love for munching on leaves and their droppings.

The researchers found that caterpillars eat so many leaves every year that their consumption actually changes the environment's nutrient cycle. Their eating habits increase greenhouse emissions since the amount of greenery available to cycle carbon from trees to the surroundings is decreased. Add to that their nitrogen-filled poo, and it's a recipe for carbon disaster. As the insects' droppings fall into Canada's lakes, the material enriches carbon dioxide-creating bacteria and decreases carbon-absorbing algae.

And according to the study, the situation will only worsen as climate change continues. Changing temperatures and ecologies have led to more of the hungry caterpillars and more of their carbon-causing actions. "These insects are basically little machines that convert carbon-rich leaves into nitrogen-rich poo," explained one of the researchers and University of Cambridge's plant scientist Andrew Tanentzap. "The poo drops into lakes instead of the leaves, and this significantly changes the water chemistry."

Tanentzap added, "We think it will increase the extent to which lakes are sources of greenhouse gases." Another one of the paper's writers, Sam Woodman, explained, "Outbreaks of leaf-eating insects can reduce the carbon dissolved in lake water by almost a third when the trees around the lake are mainly deciduous."

"It's just amazing that these insects can have such a pronounced effect on water quality," Woodman continued. "From a water quality perspective, they're a good thing, but from a climate perspective, they're pretty bad - yet they've been completely overlooked in climate models."

You can read the complete study in Nature Communications.