WASHINGTON: Researchers say they are detecting a dramatic spike in ocean surface temperatures around the world — reaching as much as 5 degrees Celsius (9 degrees Fahrenheit) above normal in the North Atlantic — and they could rise even higher.
“It is very alarming, and as temperatures keep spiking, this is not unexpected,” said Kim Cobb, a climate scientist and professor of earth, environmental and planetary sciences at Brown University in Rhode Island.
As the oceans get warmer each year, scientists say they are triggering chaotic weather patterns around the world, including torrential downpours and intense heat waves that cause flooding and severe drought.
Climate scientists attribute much of the warming to so-called greenhouse gases and say that to prevent the most severe consequences, the use of fossil fuels must be cut in half by 2030.
The most recent increase has caused the most extreme ocean heat wave in the British Isles in 170 years, according to the Met Office, the United Kingdom’s national weather service.
“This is an off-the-charts heat wave in the oceans,” said John Abraham, a climate change scientist at the University of St. Thomas in Minnesota. “The temperatures we are seeing this year are a remarkable excursion from normal temperatures.”
Oceans, which cover 70% of the Earth, have a huge impact on weather.
“When the air blows over the oceans, the air warms up and gets more humid and that drives storms,” Abraham told VOA.
“The water vapor amplifies warming by trapping outgoing radiation from escaping and that feeds the storms,” noted Kevin Trenberth, a global warming expert and a scholar at the National Center for Atmospheric Research. “So, there is a huge magnifying effect.”
A study in the journal Earth System Science Data published in April warns that oceans are heating-up more rapidly than previously thought, creating a greater risk for extreme weather, rising sea levels, and the loss of marine ecosystems.
Even a small increase in ocean temperature can have other profound effects, which include coral bleaching and more intense hurricanes.
“There is also the loss of ice, the disintegration of the Antarctic and Greenland ice sheets that are contributing to sea level rise earlier than we expected it to,” said Michael Mann, professor of environmental science at Pennsylvania State University.
There are many places in the world that will be warmer than usual this year, Abraham said.
“In South America, we expect both coasts to be warmer than average and the Caribbean and Central American regions to be both warm and dry. In large parts of Southeast Asia, we should expect drier conditions in the upcoming months.”
Adding to the already crucial situation, an El Niño has formed that is likely to bring extreme weather patterns later this year. An El Niño refers to a warming of the ocean surface in the central and eastern Pacific Ocean. Scientists say the phenomenon is not caused by global warming but may be exacerbated by it.
“It causes unprecedented but strong dry spells in many places, and droughts that may promote wildfires, such as those we’re seeing in Canada, and torrential rains in other places in the world,” said Trenberth.
“The temperatures will spike higher every time there is an El Niño,” said Abraham. “What we’re seeing now is a foretelling of our future unless we reduce our greenhouse emissions.”
“In a warmer world, we’re in for a very bumpy ride that includes extreme rainfall, mudslides, wildfires, drought and failed crop yields,” said Cobb of Brown University.
Mann said greenhouse gases need to be significantly reduced soon or the environmental consequences will become even worse.
“We need governments to provide incentives to move the energy and transportation industries away from fossil fuels and towards renewable energy,” he said.
(VOA)
Comment