Worldwide, the number of intense tropical storms has increased 80%, according to an article published by Science magazine in 2005.

According to recent studies, while the total number of hurricanes per year did not increase, the percentage of category 4 and 5 hurricanes did sharply increase during the last 35-40 years.

Most researchers agree that the warming oceans are the result of rising amounts of greenhouse gases in the atmosphere, also known as global warming. This process occurs when there are high levels of carbon dioxide in the atmosphere.

Global warming and hurricanes are linked because heat essentially is the fuel of these storms. Researchers have described hurricanes as heat engines that draw their energy upward from the warm ocean water to drive their winds; the increase in ocean temperatures is like throwing a log on a fire.

• Typhoon Tip, October 1979: largest and most intense tropical cyclone ever recorded with wind speeds of 190mph, killed 99 people in its path across the Pacific, mostly in Japan
• Hurricane Allen, August 1980: strongest Atlantic hurricane by wind speed, with sustained winds of 190mph, caused nearly 300 deaths in Haiti and severe damage in the US state of Texas
• Bangladesh cyclone known as 02B, April 1991: at least 138,000 died and up to 10 million made homeless after a 20ft storm surge
• Odisha or Paradip cyclone, October 1991: the strongest ever recorded in the northern Indian Ocean, killed about 10,000 people, mostly in India
• Hurricane Katrina, August 2005: killed at least 1,836 people after striking states of Louisiana and Mississippi and was the costliest storm in history, causing $81.2 billion in damage (with wind speeds of 175mph)
• Hurricane Wilma, October 2005: most intense tropical cyclone in the Atlantic basin with wind speeds of 185mph, killing 87 people on its path through the Caribbean and Gulf of Mexico
• Typhoon Haiyan, November 2013: the strongest storm recorded at landfall, with one-minute sustained wind speeds of 197mph, it devastated parts of the Philippines, killing at least 6,300 people