Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

Record Heat Means Hurricanes Gain Ferocity Faster

Climate
Record Heat Means Hurricanes Gain Ferocity Faster
The Copernicus Sentinel-3A satellite saw the temperature at the top of Hurricane Harvey on August 25, 2017. European Space Agency / CC BY-SA 3.0 IGO

By Tim Radford

Hurricanes are becoming more violent, more rapidly, than they did 30 years ago. The cause may be entirely natural, scientists say.

But Hurricane Harvey, which in 2017 assaulted the Gulf of Mexico and dumped unprecedented quantities of rain to cause devastating floods in Texas, happened because the waters of the Gulf were warmer than at any time on record. And they were warmer because of human-driven climate change, according to a second study.


Both studies examine the intricate machinery of a natural phenomenon, the tropical cyclone. Researchers from the Pacific Northwest National Laboratory looked at how fast four of 2017's hurricanes—Harvey, Irma, Jose and Maria—intensified: episodes in which maximum wind speed rose by at least 25 knots, which is more than 46 kilometers (approximately 29 miles), per hour within a 24-hour period. They report in Geophysical Research Letters that they combed through 30 years of satellite data from 1986 to 2015 to find a pattern.

Researchers have repeatedly warned that hurricane hazard must increase with global warming, driven by profligate human combustion of fossil fuels that dump greenhouse gases in the atmosphere. Hurricanes will hit higher latitudes and deliver more damage within the Gulf of Mexico. But climate change is only part of the answer.

The latest study did not find that storms were intensifying rapidly more often than usual. But the researchers did find that when a storm grew at speed, it became much more powerful within a 24-hour period than such storms did 30 years ago: wind speeds had gained 3.8 knots or seven kilometers (approximately 4.3 miles) an hour for each of the three decades.

And although hurricanes are driven by the warmth of the upper ocean, the researchers decided that rather than overall ocean warming, in this case the biggest factor was a natural cycle called the Atlantic Multidecadal Oscillation, which in its present phase tends to make ocean waters warmer in the central and eastern Atlantic—the spawning ground for Irma, Jose and Maria.

Warmest on Record

But when Harvey hammered the Texas coast in August 2017, the waters of the Gulf of Mexico were warmer than they had ever been. And scientists from the National Center for Atmospheric Research (NCAR) report in the journal Earth's Future that they calculated the rate of evaporation as the hurricane winds raced over the water and compared it with the levels of precipitation over the city of Houston.

To make a hurricane happen at all, ocean temperatures need to reach 26°C (approximately 79°F). When Harvey gathered its strength and its moisture, the Gulf waters had tipped 30°C.

"We show, for the first time, that the volume of rain over land corresponds to the amount of water evaporated from the unusually warm ocean," said Kevin Trenberth, a senior scientist with NCAR. "As climate change continues, we can expect more supercharged storms like Harvey."

Reposted with permission from our media associate Climate News Network.

This fall brings three new environmental movies. David Attenborough: A Life On Our Planet | Official Trailer

This week marks the official start of fall, but longer nights and colder days can make it harder to spend time outdoors. Luckily, there are several inspiring environmental films that can be streamed at home.

Read More Show Less

EcoWatch Daily Newsletter

Amazon Employees for Climate Justice walk out and rally at the company's headquarters to demand that leaders take action on climate change in Seattle, Washington on Sept. 20, 2019. JASON REDMOND / AFP via Getty Images

The world's largest online retailer is making it slightly easier for customer to make eco-conscious choices.

Read More Show Less

Trending

Moms Clean Air Force members attend a press conference hosted by Senator Tom Udall (D-N.M.) and Senator Richard Blumenthal (D-Conn.) announcing legislation to ban chlorpyrifos on July 25, 2017. Moms Clean Air Force

The Trump administration's Environmental Protection Agency (EPA) released a risk assessment for toxic pesticide chlorpyrifos Tuesday that downplayed its effects on children's brains and may be the first indication of how the administration's "secret science" policy could impact public health.

Read More Show Less
Evacuees wait to board a bus as they are evacuated by local and state government officials before the arrival of Hurricane Laura on August 26, 2020 in Lake Charles, Louisiana. Joe Raedle / Getty Images

By Maria Trimarchi and Sarah Gleim

If all the glaciers and ice caps on the planet melted, global sea level would rise by about 230 feet. That amount of water would flood nearly every coastal city around the world [source: U.S. Geological Survey]. Rising temperatures, melting arctic ice, drought, desertification and other catastrophic effects of climate change are not examples of future troubles — they are reality today. Climate change isn't just about the environment; its effects touch every part of our lives, from the stability of our governments and economies to our health and where we live.

Read More Show Less
In 'My Octopus Teacher,' Craig Foster becomes fascinated with an octopus and visits her for hundreds of days in a row. Netflix

In his latest documentary, My Octopus Teacher, free diver and filmmaker Craig Foster tells a unique story about his friendship and bond with an octopus in a kelp forest in Cape Town, South Africa. It's been labeled "the love story that we need right now" by The Cut.

Read More Show Less

Support Ecowatch