Man-made heat energy absorbed by oceans has doubled since 1997: study

WASHINGTON -- The amount of man-made heat energy absorbed by the seas has doubled since 1997, a study released Monday showed.

See Full Article

Scientists have long known that more than 90 per cent of the heat energy from man-made global warming goes into the world's oceans instead of the ground. And they've seen ocean heat content rise in recent years. But the new study, using ocean-observing data that goes back to the British research ship Challenger in the 1870s and including high-tech modern underwater monitors and computer models, tracked how much man-made heat has been buried in the oceans in the past 150 years.

The world's oceans absorbed approximately 150 zettajoules of energy from 1865 to 1997, and then absorbed about another 150 in the next 18 years, according to a study published Monday in the journal Nature Climate Change.

To put that in perspective, if you exploded one atomic bomb the size of the one that dropped on Hiroshima every second for a year, the total energy released would be 2 zettajoules. So since 1997, Earth's oceans have absorbed man-made heat energy equivalent to a Hiroshima-style bomb being exploded every second for 75 straight years.

"The changes we're talking about, they are really, really big numbers," said study co-author Paul Durack, an oceanographer at the Lawrence Livermore National Lab in California. "They are nonhuman numbers."

Because there are decades when good data wasn't available and computer simulations are involved, the overall figures are rough but still are reliable, the study's authors said. Most of the added heat has been trapped in the upper 2,300 feet, but with every year the deeper oceans also are absorbing more energy, they said.

But the study's authors and outside experts say it's not the raw numbers that bother them. It's how fast those numbers are increasing.

"After 2000 in particular the rate of change is really starting to ramp up," Durack said.

This means the amount of energy being trapped in Earth's climate system as a whole is accelerating, the study's lead author Peter Gleckler, a climate scientist at Lawrence Livermore, said.

Because the oceans are so vast and cold, the absorbed heat raises temperatures by only a few tenths of a degree, but the importance is the energy balance, Gleckler and his colleagues said. When oceans absorb all that heat it keeps the surface from getting even warmer from the heat-trapping gases spewed by the burning of coal, oil and gas, the scientists said.

The warmer the oceans get, the less heat they can absorb and the more heat stays in the air and on land surface, the study's co-author, Chris Forest at Pennsylvania State University, said.

"These finding have potentially serious consequences for life in the oceans as well as for patterns of ocean circulation, storm tracks and storm intensity," said Oregon State University marine sciences professor Jane Lubchenco, the former chief of the National Oceanic and Atmospheric Administration.

One outside scientist, Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research, also has been looking at ocean heat content and he said his ongoing work shows the Gleckler team "significantly underestimates" how much heat the ocean has absorbed.

Jeff Severinghaus at the Scripps Institute of Oceanography praised the study, saying it "provides real, hard evidence that humans are dramatically heating the planet."



Advertisements

Latest Tech & Science News

  • Cities may be 8 degrees C hotter by 2100: study

    Tech & Science CTV News
    Under a dual onslaught of global warming and localised, urban heating, some of the world's cities may be as much as 8 C warmer by 2100, researchers warned Monday. Such a temperature spike can have dire consequences for the health of city-dwellers, robbing companies and industries of able workers, and put pressure on already strained natural resources such as water. Source
  • Climate change contributing to urban 'heat islands' raising costs for cities

    Tech & Science CBC News
    Heat trapped by dark-coloured roads and buildings will more than double cities' costs for tackling global warming this century by driving up energy demand to keep citizens cool and by aggravating pollution, scientists said on Monday. Source
  • Stunning display of northern lights captured by photographers

    Tech & Science CBC News
    Did you see them? You may have been tucked into bed or inside, but on Saturday night and early Sunday morning, the sky erupted in a stunning display of northern lights that many people were able to capture with cameras. Source
  • In Canada, parks thrive but conservationists cry foul

    Tech & Science CTV News
    On a highway in Banff National Park in western Canada, tourists hastily park their cars to catch a glimpse of a bear at the edge of the forest. "We've seen some amazing animal life up here, much more than a lot of other places that we've gone camping," Tony Garland, a 60-something American who drove up from Seattle, told AFP. Source
  • Human-made chemicals found in higher quantities in deep ocean

    Tech & Science CBC News
    Human-made chemicals are penetrating deeper into the North Atlantic, a new study has found. Remember CFCs? Production of the ozone-depleting chemicals was largely phased out globally in 1994. But almost 25 years later, researchers are finding them in increasing amounts in the deeper, "older" parts of the ocean. Source
  • 'O Canada': Researcher mounts microscopic flag on penny to celebrate 150 years

    Tech & Science CBC News
    It's the smallest tribute to Canada that you'll ever see. McMaster University research engineer Travis Casagrande has carved a microscopic, 3D Canadian flag on the face of a penny. The carving — which is one one-hundredth the size of a human hair and invisible to the naked eye — is meant to be a celebration of Canada's 150th birthday this year, and a showcase of the microscopes at the Canadian Centre for Electron Microscopy at the university. Source
  • No public memorial for Harambe planned as Cincinnati Zoo looks ahead

    Tech & Science CTV News
    CINCINNATI -- No public events are planned at the Cincinnati Zoo marking the one-year anniversary of the shooting of an endangered gorilla. The zoo's dangerous-animal response team concluded the life of a 3-year-old boy who fell into the gorilla enclosure last May 28 was in danger and killed 17-year-old Harambe. Source
  • If U.S. quits climate deal, Earth expected to warm dangerously

    Tech & Science CTV News
    WASHINGTON -- Earth is likely to reach more dangerous levels of warming even sooner if the U.S. retreats from its pledge to cut carbon dioxide pollution, scientists said. That's because America contributes so much to rising temperatures. Source
  • Mother of Uber CEO Travis Kalanick killed in boat accident

    Tech & Science CTV News
    FRESNO, Calif. -- The mother of the CEO of the ride-hailing company Uber died in a boat accident Friday evening in Fresno County, the company said. Bonnie Kalanick, 71, died after the boat she and her husband, Donald, 78, were riding hit a rock in Pine Flat Lake in the eastern part of the county, authorities said. Source
  • G7 leaders agree to fight protectionism, U.S. still not on board on climate agreement

    Tech & Science CBC News
    U.S. President Donald Trump has agreed to include a pledge to fight trade protectionism in a final communique due to be released later on Saturday at the end of a summit of Group of Seven leaders, a G7 source said. Source