New research from the National Science Foundation suggests a warming Earth could mean a significant increase in voracious, plant-eating insects.
Scientists studying the Paleocene-Eocene Thermal Maximum (PETM), a period about 55 million years ago when global carbon dioxide levels spiked rapidly, found that plant fossils from that time show noticeably more insect damage than plants from before or after the PETM. They found no evidence that the plants themselves had become more appetizing to insects, or that insect species themselves changed. Rather, it appears that the PETM simply was a time when insects became more voracious and destructive.
Part of the reason might be that plants grown in high-carbon dioxide conditions are less nutritious than they otherwise would be. Some scientists have speculated that might have been the reason dinosaurs grew so large: to be able to take in large enough volumes of plant material to sustain them.
The high-temperature PETM lasted about 100,000 years.
“Our study convincingly shows that there is a link between temperature and insect feeding on leaves,” said Ellen Currano, the study’s lead author and a researcher with Pennsylvania State University and the Smithsonian Institution. “When temperature increases, the diversity of insect feeding damage on plant species also increases.”
Today’s tropics already illustrate that phenomenon, as insects there eat more plants than do their temperate-zone counterparts. Insects are also among the warm-weather species now expanding their ranges as average temperatures around the globe rise.
The researchers’ findings suggest that insects could wreak greater damage to crops and forests around the planet as the climate continues to change.
Shirley Siluk Gregory, a transplanted Chicagoan now living in Northwest Florida, represents the progressive half of Green Options' Red, Green and Blue segment. She holds a bachelor's degree in Geological Sciences from Northwestern University but graduated in 1984, just when the market for geologists was flatter than the Florida landscape. Just as well, though: she had little interest in spending her life either in a laboratory or, heaven forbid, an oil field. So, of course, she went into journalism. After extremely low-paying but fun and educational stints at several suburban Chicago weeklies and dailies, Shirley and her then-boyfriend/now-husband Scott found themselves displaced by a media buyout and spending the next several years working as freelancers. Among their credits: The Chicago Tribune, a publication for the manufactured-housing industry, and Web Hosting Magazine, a now-defunct publication that came and went with the dotcom era. Shirley's always been concerned about nature and conservation (and an avid pack-rat, as her family can attest to), but became even more rabidly interested in the environment primarily due to two factors: the growing signs that global warming was real and threatening, and the birth of her son, Noah, in 2003. Suddenly, the prospect of a world that might not be quite as habitable in 40 or 50 years took on a whole new, and personal, meaning. Living where she lives now also helped light the fire of Shirley's environmental awareness: her hometown was severely damaged by Hurricane Ivan in 2004, and beaten up again by Hurricane Dennis in 2005. That, and the fact that she and her family were vacationing in New Orleans until the day before Katrina -- and spent 12 hours driving home for a trip that normally takes 3 -- has made Shirley deeply appreciate how fragile our lifestyles are, and how dependent they are on sound management of natural resources and sustainable living practices. That's why she's become a passionate reader and writer about all things green and sustainable.