Tags Current Affairs

Issue

An analysis of satellite imagery from the past four decades suggests that global warming has increased the chances of storms reaching Category 3 or higher.

 

Background

Some scientists say that long-term natural variability in sea surface temperatures, on a time scale of decades, has played the major role in affecting storm activity.

 

Details

• But in the North Atlantic, where hurricane activity has increased in recent decades and storms have caused tens of billions of dollars of damage in the United States and the Caribbean, factors other than climate change may have played more of a role in the increase in intensity

• Physics suggests that as the world warms, hurricanes and other tropical cyclones should get stronger, because warmer water provides more of the energy that fuels these storms. And climate simulations have long showed an increase in stronger hurricanes as warming continues.

• But confirming that through observations has been problematic, because of the relatively small number of hurricanes every year and the difficulty of obtaining data on their wind speeds and other characteristics. 

• Researchers got around the limitations by using satellite images of storms worldwide and using computers to interpret them with a long-accepted pattern-matching algorithm, or set of instructions.

• The study looked at tropical storms worldwide because that provided a lot more data than looking at those in just one region.

• And every region has natural variability or other factors that can affect storm intensity and make it more difficult to tease out the effects of warming.

• The trend isn't universal. There are regions like the North Pacific, where cyclones haven't gotten stronger, likely because climate change has also moved their average storm tracks northward, to cooler regions with less ocean energy to feed them.