PARIS — Climate change isn't making cyclones like Bangladesh less frequent, but it's making them more intense and destructive, according to climatologists and weather experts. These extremely powerful natural phenomena have different names depending on the area they hit, but cyclones, hurricanes and typhoons are powerful tropical storms that can generate 10 times more energy than the atomic bomb that hit Hiroshima. They are divided into different categories according to their maximum sustained wind strength and the extent of damage they can potentially cause. "A cyclone is a low pressure system that forms in the tropics in an area hot enough to develop," said Emmanuel Clopet of the French weather office Meteo France. "It is characterized by rain/thunder clouds that begin to rotate and generate intense rain and winds, and wind-induced surges," he added. These huge weather phenomena - averaging several hundred kilometers across - are made even more dangerous by their ability to travel long distances. Tropical cyclones are categorized by wind intensity, from a tropical depression (below 40 mph), to a tropical storm (40 mph to 75 mph) and a major hurricane (above that). They are called cyclones in the Indian Ocean and South Pacific, hurricanes in the North Atlantic and Northeast Pacific, and typhoons in the Northwest Pacific. The weather agencies that monitor them use different scales to categorize them, depending on the ocean basin in which they occur. The best-known scale for measuring their intensity and destructive potential is the five-point Saffir-Simpson wind scale. (The Straits Times)