Saturday, 22 April 2017

Decline of coral

United States government scientists have found a dramatic impact from the continuing decline of coral reefs: The sea floor around them is eroding and sinking, deepening coastal waters and exposing nearby communities to damaging waves that reefs used to weaken.

The new study, conducted by researchers with the US Geological Survey, examined reefs in Hawaii, the Florida Keys, and the US Virgin Islands, finding sea floor drops in all three locations. Near Maui, where the largest changes were observed, the researchers found that the sea floor had lost so much sand that, by volume, it would be the equivalent of 81 Empire State Buildings.

"We knew that coral reefs were degrading, but we didn't really know how much until we did this study," said USGS oceanographer Kimberly Yates, the lead study author. "We didn't really realise until now that they're degrading enough that it's actually affecting the rest of the sea floor as well."
The work was published yesterday in the journal Biogeosciences.

Coral reefs naturally generate sand as hard coral skeletons die, and their calcium carbonate bodies become the next layer of the sea floor.

Meanwhile, the living tops of coral columns grow taller and taller, which allows them to keep pace in eras of rising seas.

But as corals are subjected to more and more assaults from a combination of global climate change, local pollution, and direct human-caused damage, this natural dynamic appears to have been undermined, and sea floor accretion has swung to erosion.ocesses may well also be afoot - reefs across the world are generally threatened.

Monday, 17 April 2017

New crack in one of Greenland's glaciers

The first photographs of a new and ominous crack in Greenland's enormous Petermann Glacier were captured by a Nasa airborne mission at the weekend.

Nasa's Operation IceBridge, which has been flying over northwest Greenland for the past several days, took the photos after being provided coordinates by Stef Lhermitte, a professor at Delft University of Technology in the Netherlands, who had spotted the oddly located chasm by examining satellite images.

The Nasa pictures make clear that a significant new rift has opened near the centre of the glacier's floating ice shelf - an unusual location that raises questions about how it formed. Moreover, this crack is not so distant from another much wider and longer crack that has been slowly extending toward the shelf's centre from its eastern side wall.

Saturday, 15 April 2017

Climate change: Turbulence to get a whole lot worse on airplanes

A scary new study has warned one of the worst things about flying is about to get much worse: turbulence.

Bouts of turbulence that are strong enough to toss passengers around the cabin could become up to three times more common - and it's all thanks to climate change, according to

Scientists at the University of Reading in the UK have carried out a first-ever study into the relationship between anthropogenic climate change and clear-air turbulence.

They looked at different strengths of turbulence and how each will change in the future, based on a study of the North Atlantic flight corridor between Europe and the United States.

According to the results, light turbulence in the atmosphere would be likely to increase by about 59 per cent in the future, moderate turbulence would increase by 94 per cent and moderate-to-severe turbulence by 127 per cent.

The strongest kind - severe turbulence - was to increase by a whopping 149 per cent, according to the report.

The scientists found these increases would be caused by climate change generating stronger wind shears within the jet stream, which is a major cause of turbulence.

And while even the scariest jolts are unlikely to cause a plane to fall out of the sky, turbulence does cause injuries, including serious injuries, as a result of loose objects and unbuckled passengers and crew being thrown around the cabin

Tuesday, 11 April 2017

1450km of Great Barrier Reef has bleached badly

Scientists just back from a 8045km aircraft survey of Australia's Great Barrier Reef pronounced a dire verdict: Warm waters have severely bleached large swaths of its corals for the second year in a row in a deadly one-two punch.
In 2016, two thirds of corals in the northern sector of the reef died after severe bleaching from unusually warm waters.

Now this year, researchers with the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Queensland, who reported the previous findings, say that the reef's central sector has been hit by another year of damaging warmth.
"We've had a back-to-back bleaching for the first time," said Terry Hughes, who directs the centre.
"So we redid our aerial surveys again, which was a bit tough. I was hoping to never have to do it again."

After that first survey, Hughes tweeted: "I showed the results of aerial surveys of #bleaching on the #GreatBarrierReef to my students, And then we wept."

Coral bleaching occurs when unusually warm waters provide a stress to corals that in turn trigger a mass exodus of photosynthetic algae, called zooxanthellae, from their cells. The corals lose colour and turn white, an outward indicator that their metabolism has been upended. The stronger the bleaching and the longer it goes on, the more likely corals are to die.

Cases of severe turbulence to soar thanks to climate change, say scientists

Turbulence strong enough to throw unbuckled passengers around the cabin of a plane could become three times more common due to climate change.

That's according to scientists at the University of Reading, which has conducted a pioneering study into the relationship between anthropogenic climate change and transatlantic clear-air turbulence, the Daily Telegraph reports.

The study examined several different turbulence strengths and looked at how they might change in future.

The results revealed that the average amount of light turbulence in the atmosphere is likely to increase by 59 per cent, light-to-moderate turbulence by 75 per cent, moderate turbulence by 94 per cent, moderate-to-severe by 127 per cent, and severe by 149 per cent.

Climate change is generating stronger wind shears within the jet stream and causing the atmosphere to become more unstable, the report claims.

"Our new study paints the most detailed picture yet of how aircraft turbulence will respond to climate change," said Dr Paul Williams, who conducted the research.

"For most passengers, light turbulence is nothing more than an annoying inconvenience that reduces their comfort levels, but for nervous fliers even light turbulence can be distressing.

"However, even the most seasoned frequent fliers may be alarmed at the prospect of a 149 per cent increase in severe turbulence, which frequently hospitalises air travellers and flight attendants around the world."

Sunday, 9 April 2017

Icebergs cause chaos for freighters

More than 400 icebergs have drifted into the North Atlantic shipping lanes over the past week in an unusually large swarm for this early in the season, forcing vessels to slow to a crawl or take detours of hundreds of kilometres.

Experts are attributing it to uncommonly strong counter-clockwise winds that are drawing the icebergs south, and perhaps also global warming, which is accelerating the process by which chunks of the Greenland ice sheet break off and float away.

As of Tuesday, there were about 450 icebergs near the Grand Banks of Newfoundland, up from 37 a week earlier, according to the United States Coast Guard's International Ice Patrol. Those kinds of numbers are usually not seen until late May or early June. The average for this time of year is about 80.

In the waters close to where the Titanic went down in 1912, the icebergs are forcing ships to take precautions. Instead of cutting straight across the ocean, transAtlantic vessels are taking detours that can add around 650km to the trip - a day and a half of added travel time for many large cargo ships.

Close to the Newfoundland coast, cargo ships owned by Oceanex are throttling way back to 5.5-7.5km/h as they make their way to their home port in St John's, said executive chairman Captain Sid Hynes.

One ship was pulled out of service for repairs after hitting a chunk of ice, he said.
"It makes everything more expensive," Hynes said yesterday.

"You're burning more fuel, it's taking a longer time, and it's hard on the equipment." He called it a "very unusual year".

Friday, 7 April 2017

Your flight could be powered by rubbish from Nevada

Cathay Pacific broke new ground when it liked a fuel-from-garbage firm so much that it bought into the company.

Its biofuel manager, Jeff Ovens, says he was presented with a blank canvas in 2009 when the Hong Kong-based airline began looking into new ways of helping to power its fleet.
Back then, a looming European Union emissions trading scheme (ETS) was providing the impetus for airlines to look at what they could do to cut their carbon footprint.

While the ETS was put on ice, within Cathay Pacific there was an acknowledgement that there would be a global scheme covering all airlines - as was signed last year.

Ovens says Cathay developed its own target - carbon-neutral growth from 2020 - and put out feelers for companies making fuels from different kinds of feedstock.

Three years later, it took the unusual step of making an equity investment in United States biofuel developer Fulcrum Bioenergy.

There is also an agreement to take 1.4 billion litres of biofuel over 10 years, starting from 2019, once the manufacturing plant is finished.

"Other airlines were aligning themselves for an offtake agreement and nothing else," says Ovens.