The classic study for ecosystem impacts from increasing climate variability is a 2002 paper published about the checkerspot butterfly, a subspecies that was wiped out in the San Francisco Bay area, partially because of habitat loss—which made them less resilient—but also because annual precipitation and temperatures became more volatile and caused a mistiming between the emergence of larvae and the plants they feed on. Caterpillars hatch in April, but will starve if they don’t grow large enough before the onset of the summer drought, when the seasonal plants they depend on—including dwarf plantain and Indian paintbrush—die. The longer they can feed on the plant, the better their chance of survival. The butterflies feed again in November when the rains resume.
“These butterfly populations were driven to extinction because of variability” in precipitation, said John McLaughlin, an ecologist at Western Washington University who worked on the study. “We should be paying a lot more attention to these kinds of things.”