By now, it’s well known that their predicament was caused by rising floodwaters in the cave. What is less known is that the pattern of precipitation that ensnared them is in keeping with broader changes to the region’s seasonal monsoon that researchers have attributed to climate change.
“Over the South Asian landmass, we’ve seen that extreme rainfall events have become more frequent,” said Amit Tandon, a professor at the University of Massachusetts Dartmouth who studies ocean systems.
No one is suggesting that climate change itself was responsible for trapping the boys in the cave. Brief downpours have always been common during Thailand’s wet season, which runs from late May to early October. Periods of a week or two of relatively heavy rainfall are punctuated by drier periods.
The alternating dry and wet periods are called the intraseasonal oscillation, said Arnold L. Gordon, a professor of earth and environmental sciences at Columbia University. That variation has always happened, unrelated to climate change. But what has changed in recent years is that those wet periods have been wetter.
“It’s likely climate change, in the sense that there’s more moisture in the air,” Dr. Gordon said. Warmer air can hold more moisture, and “when the air has more moisture in it, you would get wetter wet bands and drier dry bands,” he said.
Flash floods were known to be a danger in the cave, and a sign at the entrance warned against entering in the rainy season. But the strongest rains normally begin in July, so the boys and their coach may have been caught off guard when they ventured inside the relatively dry cave on June 23. Though the total June rainfall in the area, 9.6 inches, was only slightly higher than average, five of those inches fell between June 21 and 28, according to Eric Leister, a senior meteorologist with AccuWeather. The resulting floodwaters trapped the team and complicated rescue efforts.
“With any individual event, it’s hard to pinpoint the blame to climate change,” Dr. Tandon said. “But it’s certainly in keeping with the trends, in the sense of, ‘Do we see, statistically, more events like this?’ And the answer is, ‘Yes.’”
Source: NY Times | 11 July 2018