The most powerful tropical cyclone ever recorded slammed into the Philippines in November of 2013. Typhoon Haiyan packed sustained winds of 195 miles per hour — the strongest of any typhoon or hurricane ever recorded at landfall. Over a few days, as it roared across the islands and then into mainland Asia, it killed as many as 7500 people and caused billions of dollars in damages.
Some recent studies say that Haiyan is part of a trend. According to one of the studies, from 1977 to 2013 the average intensity of typhoons that made landfall in parts of south and southeast Asia increased by 12 to 15 percent. And the trend may continue.
Researchers compared datasets compiled by two major typhoon-watching groups. They found that both sets revealed big changes in the intensity of typhoons that made landfall in that region. The number of storms of category 4 and 5 — the strongest of all — jumped by 40 percent. And the proportion of these storms compared to all typhoons doubled.
The researchers say that the jump is caused by warmer surface temperatures in the shallow waters on the rim of south and southeast Asia. The average temperature has jumped by about one degree Fahrenheit since the 1970s. Since tropical storms feed off warm water, the increase provides more energy to fuel bigger storms.
Those same waters are forecast to get even warmer by the end of the century. That could mean that more big storms could hit parts of Asia in the decades ahead.