The Philippines sees an average of 20 tropical cyclones a year, with eight or nine making landfall. - AFP
MANILA: A warming climate fuelled the blitz of six powerful storms that hit the Philippines within a matter of weeks this year, according to a new study.
The conditions that enabled the unusual string of tropical cyclones late in the season, including higher sea surface temperatures, were made nearly twice as likely by human-induced climate change, according to World Weather Attribution, an international group of scientists that examines the link between extreme weather and climate change. That’s compared with a scenario where global temperatures remained at pre-industrial levels, it said.
"The barrage of typhoons was supercharged by climate change,” Ben Clarke, one of the study’s authors and a researcher at Imperial College London’s Center for Environmental Policy, said in a statement.
Rising greenhouse gas emissions are increasing the frequency and intensity of extreme weather events across the planet, according to many top climate scientists. Such volatile weather patterns have battered developing and developed countries alike, leading to calls for more financing to improve preparedness and adaptation to climate change.
Of the six tropical cyclones that hit the South-East Asian country over a three-week period in October and November, five made landfall. At least 150 people were killed, crops were ravaged, swathes of the country were drenched, and GDP growth took a hit.
"Having five typhoons in less than a month was extraordinary and our study found that climate change made them much more destructive,” said Philippine weather agency climatologist, Joseph Basconcillo, who contributed to the WWA study.
Using observational and model data, scientists found that human-driven climate change increased the potential intensity of the storms by 7.2km (4.5 miles) per hour. Potential intensity is the theoretical maximum wind speed of a tropical cyclone depending on conditions that allow such storms to form and strengthen.
The Philippines sees an average of 20 tropical cyclones a year, with eight or nine making landfall. Because of global warming, the likelihood of at least three major typhoons directly striking the archipelago in a single year has increased by 25% compared with a climate that’s 1.3 degrees cooler, as it was in the pre-industrial era, the study found.
Such events would only have occurred once every 19 years, while in the present climate this is now expected once every 15 years. The scientists defined a major typhoon as having the equivalent strength of a Category 3 hurricane or above on the five-step Saffir-Simpson scale.
The WWA’s report echo findings by other academics.
"Warming sea surface temperatures due to human activities intensify tropical cyclone wind speeds, making them potentially more damaging,” said Rafaela Jane Delfino, a professor at the University of Philippines’ Institute of Environmental Science and Meteorology. She has also found that warmer sea surface temperatures cause wetter storms, bringing up to 15% more rainfall and raising the risk of flooding. - Bloomberg
