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Category — Ocean changes

NOAA’s satellites are on the chopping block. Here’s why we need them.

Our eyes in the sky are facing budget cuts On Friday, The Washington Post reportedly obtained a memo from within the Trump administration about proposed funding for National Oceanic and Atmospheric Administration (NOAA). The memo outlined steep cuts to several divisions, including the elimination of the $73 million Sea Grant research program, cuts to climate research… [Read more →]

March 7, 2017   No Comments

Atlantic depths may hold key to heat hiatus

Tim Radford

A jellyfish floats just above the seafloor of the deep Atlantic Ocean. Image: NOAA/OAR/OER via Wikimedia Commons

A jellyfish floats just above the seafloor of the deep Atlantic Ocean. Image: NOAA/OAR/OER via Wikimedia Commons

Researchers analysing millions of oceanographic measurements believe they may finally have got to the bottom of the conundrum about why there is a slowdown in global warming despite greenhouse gas emissions rising.

For years, researchers have puzzled over the temperature rises that haven’t happened – but scientists in China and the US believe they have cracked the mystery of the missing heat.

While calculations indicate that global average temperatures should be rising predictably, the planetary thermometers tell a different story.

But now Xianyao Chen, an oceanographer at the Ocean University of China in Ongdao, and Ka-Kit Tung, an atmospheric scientist at the University of Washington in Seattle, report inScience journal that they think they know where the notional extra heat has gone. It is at the bottom of the Atlantic Ocean.

And this time their conclusion isn’t based only on mathematical models and computer simulations. In their research − funded by the US National Science Foundation and theNational Natural Science Foundation of China – they analysed millions of measurements of temperature and salinity taken by oceanographic instruments since 1970, and tracked the pathways that the heat must have taken since the beginning of the 21st century. [Read more →]

August 22, 2014   No Comments

Equatorial fish feel the heat

Alex Kirby

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Weaving through the coral: Small fish like these are important sources of food for larger reef species. Image: D. Dixson

Many species of fish living near the Equator are sensitive to variations in heat and will not thrive in the warmer oceans of the future, scientists in Australia have found.

Lying in a hot bath may be a pleasant experience, because you can always get out when you’ve had enough. For some of the fish that swim in equatorial seas, though, that is not an option: climate change threatens to make the water not just uncomfortable, but unendurable.

An international team of researchers based in Australia reports in Global Change Biology that the rapid pace of climate change is threatening the future of some of the fish which live near the Equator.

Over a 14-day period the team tested four species of damsel fish and two of cardinal fish. They say: “Our results indicate that low-latitude reef fish populations are living close to their thermal optima and may be more sensitive to ocean warming than higher-latitude populations.”

“Our studies found that one species of fish could not even survive in water just 3°C warmer than it lives in now”, says the lead author of the study, Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University in Queensland.

Dr Rummer and her colleagues studied six common species living on coral reefs near the Equator. She says many species in this region experience only a very narrow range of temperatures throughout their lives, and so are probably adapted to perform best at those temperatures.

The world’s oceans are projected to warm by 2-3°C by the end of this century. “Such an increase in warming leads to a loss of performance”, Dr Rummer said. “Already, we found four species of fish are living at or above the temperatures at which they function best.” [Read more →]

February 15, 2014   No Comments

Coastal flooding ‘may cost $100,000 bn a year by 2100′

Tim Radford

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The only way is up: A rapid start on cutting emissions is essential. Image: Jan Smith via Wikimedia Commons

On the world’s present course, the cost by 2100 of tackling coastal flooding could be beyond the reach of the poorest countries – and ruinously expensive for richer ones.

If global warming continues on its present ominous path, and if no significant adaptation measures are launched, then coastal flooding could be costing the planet’s economies $100,000 billion a year by 2100.

And perhaps 5% of the people on the planet – up to 600 million people – could be hit by coastal flooding by the end of the century, according to new research in the Proceedings of the National Academy of Sciences.

Jochen Hinkel from the Global Climate Forum in Berlin and colleagues have compiled, for the first time, global simulation results on future flood damage to buildings and infrastructure on the world’s coastal flood plains.

They expect drastic increases in economic damage because, as sea levels rise with the decades, so will population and investment: there will be more people with more to lose.

Right now, coastal floods and storm surge damage cost the world between $10 billion a year and $40 billion. But as the megacities grow – think of Lagos, or Shanghai, or Manila – more people will be at risk, and, among them, greater than ever numbers of the poorest.

“If we ignore this problem, the consequences will be dramatic,” says Hinkel. “Countries need to take action and invest in coastal protection measures, such as building or raising dykes, amongst other options.” [Read more →]

February 11, 2014   No Comments

Trade winds draw ‘missing’ warmth to deep ocean

Tim Radford

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The trade winds make their mark on Hawaii – and they may explain where the “missing” warmth has gone. Image: Richard B. Mieremet, Senior Advisor, NOAA OSDIA

Contrary to some reports, global warming hasn’t stopped or slowed at all, new research suggests. The trade winds have simply carried the heat into the Pacific Ocean – temporarily.

Australian and US scientists think they know where a lot of global warming has been concentrated: it has been tucked away below the surface waters of the western Pacific Ocean. And the agency that took the heat out of the atmosphere and transferred it into a liquid form could have been the equatorial trade winds.

Matthew England from the Australian Centre of Excellence for Climate System Science and colleagues report in Nature Climate Change that a dramatic acceleration in the winds has drawn heat from the atmosphere and transferred it to the ocean: cooler waters have risen to the surface to mask the transaction.

Climate sceptics – and some climate scientists – talk about a slowdown, or a pause, or a hiatus in global warming. In fact, temperatures have gone on rising and 13 of the 14 warmest years ever recorded have all occurred since 2000. But the rate of rise in global average temperatures since 2000 has not been as fast as the rate during the 1980s and 1990s.

Since greenhouse gas levels have continued to rise, and since scientists are sure of their atmospheric physics, then there was some “missing heat” to be accounted for.

Researchers have variously suggested that a puzzling increase in deep ocean temperatures could be one explanation or that perhaps the unevenness of temperature measurements around the planet might be another. But both suggestions were hypotheses: nobody had an answer that could be tested by any kind of experiment. [Read more →]

February 10, 2014   No Comments

Atlantic changes are warming Antarctic

Tim Radford

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Ice covering the Bellingshausen Sea in Antarctica – and feeling the impact of changes in the Atlantic. Image: NASA/Michael Studinger via Wikimedia Commons

More evidence has emerged that changing climate in one region can have unpredictable effects many thousands of miles away.

The Antarctic Peninsula is now the strongest-warming region on the planet. Blame that on changes in the faraway North and tropical Atlantic Ocean.

Xichen Li of New York University in the US and colleagues matched sea surface temperature variations in the northern Atlantic over a three-decade period against long-term changes in the Antarctic. They found a clear correlation, they report in Nature.

They also observed that warming Atlantic waters were followed by changes in sea level pressure in the Antarctic’s Amundsen Sea, and these changes also preceded changes in sea ice between the Ross and Amundsen-Bellinghausen-Weddell Sea. Both stretches of water lie many thousands of miles south of the Atlantic.

Correlations are not causes, so the authors then followed up their observational data by experiments with computer models of the global atmosphere. When they simulated a warming of the North Atlantic, the model “changed” the climate in Antarctica.

That Pacific Ocean temperatures can affect Antarctica is no surprise: such things have been linked to the El Niño cycle, a periodic natural pulse of heat in the equatorial Pacific. [Read more →]

January 31, 2014   No Comments

Right whales go wrong way

Kieran Cooke

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A right whale mother and calf: Warmer waters may be changing their feeding grounds. Image: NOAA Photo Library via Wikimedia Commons

One of the world’s rarest whale species seems to have deserted its habitual feeding grounds during 2012 – and scientists think climate change may be a factor.

A mystery is unfolding in the waters of the North Atlantic. Every summer and autumn, numbers of North Atlantic right whales gather in the waters between the eastern Canadian provinces of New Brunswick and Nova Scotia to feed on massive amounts of zooplankton.

But this year the right whales – one of the rarest and most endangered animals on earth – have not turned up in a stretch of water called the Bay of Fundy.

While no-one is sure what is causing the change in the whales’ behaviour, a report in the Yale environment360 online magazine says alterations in the whales’ feeding patterns are taking place against a backdrop of major climate-related ecosystem shifts throughout the north-west Atlantic Ocean.

The right whale – Eubalaena glacialis – came by its name because it was considered by whalers as “the right whale” to hunt, due to its large concentrations of valuable blubber.  It was also easy prey: adult right whales average between 12 and 16 metres in length and can weigh up to 70 tons. They move relatively slowly through the water and float when killed, making them easy to handle. [Read more →]

December 9, 2013   No Comments

Natural defenses can best protect coasts

Tim Radford

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Jon Woodruff and Christine Brandon survey sediments after Superstorm Sandy. Image: Courtesy of UMass Amherst

Many shorelines around the world are at risk – not just from extreme weather, but from far more gradual threats. And often the best protection comes from nature.

It isn’t just the catastrophic storms and tropical cyclones that threaten disaster for the world’s coastal cities. Simple, insidious things like sea level rise, coastal subsidence and the loss of wetlands could bring the sea water coursing through city streets in the decades to come.

Jonathan Woodruff of the University of Massachusetts Amherst in the US and colleagues report in Nature that shorelines are increasingly at risk, and humans must adapt and learn to live with increasing hazard.

Many of the world’s great cities are on low-lying coastal plains, or on river estuaries, and are therefore anyway at risk as sea levels rise because of global warming.

But human action too – by damming rivers, by extracting ground water and by building massive structures on sedimentary soils – has accelerated coastal subsidence. Add to this the possibility of more intense tropical cyclones as sea surface temperatures rise, and coastal cities face a stormy future.

On 29 October 2012 Superstorm Sandy brought a surge of sea water into the streets, subway tunnels and basements of New York City and caused $65 billion worth of damage along the entire eastern seaboard of the US. It was an unprecedented event. But it may happen again. [Read more →]

December 5, 2013   No Comments