Unchecked Global Warming Could Collapse Whole Ecosystems, Maybe Within 10 Years
Global warming is about to tear big holes into Earth's delicate web of life, pushing temperatures beyond the tolerance of thousands of animals at the same time. As some key species go extinct, entire ecosystems like coral reefs and forests will crumble, and some will collapse abruptly, starting as soon as this decade, a new study in the journal Nature warns.
Many scientists see recent climate-related mass die-offs, including the coral bleaching of the Great Barrier Reef and widespread seabird and marine mammal mortality in the Northeastern Pacific linked to a marine heat wave, as warning signs of impending biodiversity collapse, said lead author Alex Pigot, a biodiversity researcher at University College, London. The new study shows that nowhere on Earth will escape the impacts.
"In the U.S., the southern states from Texas to Florida, the Appalachians and the West Coast are projected to be at particularly high risk, with between 20 and 40 percent of species facing conditions beyond anything they have previously experienced," Pigot said.
In those regions many species live in small geographic areas under a narrow range of climatic conditions. As global warming heats their habitat to the point that it is intolerable, many species have no place to go. Some will go extinct, with a domino effect that affects scores of other species. If it gets too hot for bumblebees, for example, it affects the reproduction of plants. If it gets too warm for insects and reptiles, it affects food supplies for birds and mammals.
"I hope our predictions are wrong. But increasingly, what we're observing around us are the signs of this happening," Pigot said, referring to research showing how global warming affects individual species. "I think these studies are showing that many species are already living very near their thermal limits. Our results suggest that these losses are likely to involve multiple species near simultaneously rather than happening gradually, one species at a time," he said.
At the current rate of warming, abrupt exposure events in tropical oceans will begin before 2030 and spread to tropical forests and higher latitudes by 2050. The risks decrease and arrive more slowly if global warming is capped at less than 3.6 degrees Fahrenheit, as per the goals of the 2015 Paris climate agreement, the study concluded.
"If we can avert the worst of the warming we can buy extra time," Pigot said. "Even if we can get a few extra decades, it gives us time to work on expanding protected areas, or deciding on whether to try things like assisted migration and assisted evolution."Read the full and original article at Inside Climate News