‘Humanity faces simultaneous climate disasters’

PARIS: By century’s end, many parts of the world may have to cope with up to six climate catastrophes at once, ranging from heat waves and wildfires to diluvian rains and deadly storm surges, researchers warned on Monday.

"Human society will be faced with the devastating combined impacts of multiple interacting climate hazards," said co-author Erik Franklin, a researcher at the University of Hawaii’s Institute of Marine Biology. "They are happening now and will continue to get worse," he told AFP.

Overloading the atmosphere with carbon dioxide, methane and other greenhouse gases has unleashed a maelstrom of life-threatening forces. It begins with rising temperatures, which -- in normally dry regions -- lead to drought, heatwaves and deadly wildfires, such as those ravaging California. In wetter climes, the result is heavy rainfall and flooding.

Over the oceans, global warming creates larger superstorms whose destructive power is enhanced by rising seas. Up to now, scientists have mostly studied these climate change impacts one-by-one, obscuring the possibility -- and soon the likelihood -- that human communities will be hammered by more than one at a time, the study found.

Last year, for example, Florida experienced extreme drought, record-high temperatures, more than 100 wildfires, and Hurricane Michael, the most powerful storm to ever hit its Panhandle. "A focus on one or few hazards may mask the impacts of other hazards, resulting in incomplete assessments of the consequences of climate change on humanity," said lead author Camilo Mora, a professor at the University of Hawaii.

The future risk of dealing with multiple climate impacts at once depends on geography and whether humanity succeeds in rapidly drawing down greenhouse gas emissions.

If, against the odds, humanity manages to cap global warming at two degrees Celsius (3.6 degrees Fahrenheit) above preindustrial levels, for example, New York City will likely face a single climate hazard -- a powerful storm, perhaps -- in any given year at the end of the century. The Paris climate treaty, inked by 195 nations in 2015, calls for holding the rise in temperature to "well below" 2C.