Climate change fuels extreme rainfall and stronger typhoons

Climate warming is altering rainfall patterns around the world, scientists claimed in a research published on Friday, potentially worsening typhoons and other tropical storms.

The year’s most powerful typhoon hit Taiwan, the Philippines, and then China this week, closing schools, companies, and financial markets as wind gusts reached 227 kph (141 mph). Hundreds of thousands of people were evacuated along China’s eastern coast ahead of Thursday’s storm.

Stronger tropical storms are part of a larger trend of weather extremes caused by rising temperatures, according to scientists.


Researchers from the China Academy of Sciences, lead by Zhang Wenxia, examined historical meteorological data and discovered that “precipitation variability,” or greater swings between wet and dry weather, had increased throughout around 75% of the world’s geographical area.

Warming temperatures have increased the atmosphere’s ability to hold moisture, resulting in larger swings in rainfall, according to an article published in the Science journal.

“(Variability) has increased in most places, including Australia, which means rainier rain periods and drier dry periods,” said Steven Sherwood, a scientist at the Climate Change Research Centre at the University of New South Wales who did not participate in the study.

“This is going to increase as global warming continues, enhancing the chances of droughts and/or floods.”

Fewer, but more powerful storms.

Scientists believe that climate change is altering the behavior of tropical storms, particularly typhoons, making them less common but more intense.

“I believe higher water vapour in the atmosphere is the ultimate cause of all of these tendencies toward more extreme hydrologic phenomena,” Sherwood told the news agency Reuters.

Typhoon Gaemi, which made landfall in Taiwan on Wednesday, was the most powerful to strike the island in eight years.

While it is difficult to link particular weather events to climate change, models suggest that global warming strengthens typhoons, according to Sachie Kanada, a researcher at Japan’s Nagoya University.

“In general, warmer sea surface temperature is a favourable condition for tropical cyclone development,” she further stated.

In its “blue paper” on climate change, issued this month, China stated that the number of typhoons in the Northwest Pacific and South China Sea had decreased dramatically during the 1990s, but they were becoming more powerful.

Taiwan likewise stated in its climate change study, issued in May, that climate change was projected to reduce the overall number of typhoons in the region while increasing their intensity.

Feng Xiangbo, a tropical cyclone research scientist at the University of Reading, explained that the drop in the number of typhoons is due to an uneven pattern of ocean warming, with temperatures rising quicker in the western Pacific than in the east.

Water vapour capacity in the lower atmosphere is predicted to grow by 7% for every 1°C increase in temperature, with tropical cyclone rainfall in the United States increasing by up to 40% for every single degree rise, he said.