3216. Is the Great Barrier Reef "too Big to Fail"?

By Livia Albeck-Ripka, The New York Times, April 3, 2019

Corals around islands on the Great Barrier Reef off the coast of Australia in November. A study found that mass bleaching events had not only caused adult corals to die off, but also led to a decline in new corals settling on the reef.CreditCreditDavid Gray/Reuters

MELBOURNE, Australia — For millenniums, ecosystems have withstood fires, floods, heat waves, drought and even disease by adapting and rebuilding their biodiverse communities.

But according to new research, there is a limit to what even the largest and most resilient places can stand, and climate change is testing that limit by repeatedly disturbing one of the earth’s most precious habitats: the Great Barrier Reef.

The study, released Wednesday in the journal Nature by researchers from the ARC Center of Excellence for Coral Reef Studies in Australia, monitored the death and birth of corals following ocean heat waves that caused mass bleaching of the Great Barrier Reef in 2016 and 2017.

Not only did many of the adult corals die off, but for the first time, researchers observed a significant decline in new corals settling on the reef, compromising its capacity to recover.

“There are so many corals, and it’s been disturbed many times in the past,” said Andrew Baird, chief investigator at the research center and one of the paper’s lead authors.

“We never thought we’d see this happen,” he said.

The study is the first to show the collapse of fundamental ecosystem processes in a marine environment, Professor Baird said.

“We thought the Barrier Reef was too big to fail,” he said, “but it’s not.”

The Great Barrier Reef, off Australia’s east coast, covers 133,000 square miles and can be seen from outer space. It pumps 6.4 billion Australian dollars, or $4.5 billion, into the Australian economy per year and supports tens of thousands of jobs, according to 2017 figures from Deloitte.

But in recent years, research has shown that the time left to save it is growing short.

Since 1998, the Great Barrier Reef has suffered four mass bleaching events, two of them back to back in 2016 and 2017. While coral populations can recover from a bleaching event — which stresses individual corals and strips them of their vibrant color — they need up to a decade to do so. And if carbon emissions continue at the high-emissions scenario, bleaching will occur twice every decade starting in 2035, and annually after 2044, according to climate models from Unesco.

Coral reefs were among the first ecosystems to respond to the rise in global temperatures, he said, “but it’s only a matter of time before these changes are happening in our back gardens.”

According to the researchers’ findings, the settlement of baby corals on the reef declined 89 percent last year. The coral that experienced the most significant decline in new organisms, at 93 percent, was a type called Acropora, which provides most of the reef habitat that supports thousands of other species, including coral trout, clown fish and triggerfish.

Adult corals that were further south escaped bleaching, but they were too far from the bleached northern reefs to help them replenish, the scientists found. They also explored the impact of back-to-back cyclones in 2014 and 2015 on the reef’s north at Lizard Island, which, despite killing off 80 percent of the adult corals, did not cause a decline in new corals settling.

“Cyclones are fairly patchy,” Professor Baird said, whereas heat and bleaching “just kills everything.”

The corals that do manage to survive such trauma, however, were found to be more resistant to periods of extreme warmth in a separate study conducted by Professor Baird and his colleagues last year. Scientists have been trying to breed the most resilient forms of coral in the hope that they can use these to repopulate the reef.

While crucial, such projects are limited, said Mark Eakin, the coordinator of the National Oceanic and Atmospheric Administration’s Coral Reef Watch program, who was not involved in the study but has previously worked with the Australian researchers.

“Those are at the scale of a large family garden,” he said of the restoration efforts, whereas the collapse of the Great Barrier Reef would mean “the loss of an entire seascape,” akin, he said, to the fall of the Roman Empire.

“This is just further evidence of how much damage climate change is having,” Dr. Eakin said.

Russ Babcock, a senior research scientist at an Australian government agency called the Commonwealth Scientific and Industrial Research Organization, said the study, which he was also not involved in, had confirmed many scientists’ worst fears.

“All ecosystems have some things in common, and one of them is the ability to recover,” he said. “There’s going to be no lucky escape.”

2887. Damage to Great Barrier Reef From Global Warming Is Irreversible, Scientists Say

By Jacqueline Williams, The New York Times, April 19, 2018

A diver surveying damaged coral in the Great Barrier Reef after a mass bleaching in 2016. Photo:

XL Catlin Seaview Survey, via Agence France-Presse — Getty Images

SYDNEY, Australia — An underwater heat wave that damaged huge sections of Australia’s Great Barrier Reef two years ago spurred a die-off of coral so severe that scientists say the natural wonder will never look the same again.

Scientists said nearly one-third of the reef’s coral were killed when ocean temperatures spiked in 2016, a result of global warming, according to a study published Wednesday in the journal Nature.

The damage to the reef, one of the world’s largest living structures, has also radically altered the mix of its coral species, scientists said.

“The reef is changing faster than anyone thought it would,” said Terry P. Hughes, the lead author of the study and the director of a government-funded center for coral reef studies at James Cook University in Queensland.

“One thing we can be sure about is the reef isn’t going to look the same again,” Professor Hughes said.

The reef is home to thousands of species, including sharks, turtles and whales. Australia relies on it for about 70,000 jobs and billions of dollars annually in tourism revenue, all now threatened by years of accumulated damage.

The study’s authors estimated how much coral had died in the immediate aftermath of the 2016 heat wave, and then returned nine months later to discern how many corals had regained their color — a sign of restored health — and how many had died. Their report describes a catastrophic die-off on the northern part of the reef, impacting the mix of coral species.

Professor Hughes said scientists had predicted a mass die-off resulting from global warming, but “what the paper shows is that it’s well underway.” He added, “That transition is happening here and now.”

Corals require warm water to thrive, but they are extremely sensitive to heat, and an increase of two or three degrees Fahrenheit above normal can kill them.

Scientists said that if nations honored global commitments in the Paris climate accord aimed at preventing temperatures from rising more than 2 degrees Celsius, Australia would still have the Great Barrier Reef in 50 years. It would still look very different from today.

But if greenhouse gas emissions continue on their current trajectory, the reef will be unrecognizable, they said.

“We’re in unchartered territory,” Professor Hughes said, adding, “Where we end up depends completely on how well or how badly we deal with climate change.”

The Great Barrier Reef has bleached four times since 1998, according to scientists. 

Record high temperatures in 2016 were followed by another bleaching event last year.

“We’re now at a point where we’ve lost close to half of the corals in shallow-water habitats across the northern two-thirds of the Great Barrier Reef due to back-to-back bleaching over two consecutive years,” said Sean Connolly, also with the center for coral reef studies at James Cook University.

2337. Australia, Fearing Fewer Tourists, Has Chapter Taken Out of UN Climate Report

By Michelle Innis, The New York Times, May 27, 2016

SYDNEY, Australia — Leading scientists in Australia and abroad have expressed concern that a new United Nations report about the impact of climate change on dozens of World Heritage sites is absent a chapter describing damage to the Great Barrier Reef, after the Australian government requested that the section be cut.

“I was amazed,” the lead author of the report, Adam Markham, deputy director of climate and energy programs at the Union of Concerned Scientists, said by telephone.

The Australian government requested that the chapter be removed from the report, issued by Unesco and the United Nations Environment Program on Thursday, so that further accounts of damage to the reef, the world’s largest coral ecosystem, would not adversely affect tourism.

In a statement on Friday, the Department of the Environment said “experience had shown that negative comments about the status of World Heritage-listed properties impacted on tourism.” The statement went on to say that the department did not support any of the country’s World Heritage-listed properties being included in “such a publication.’’

Environment Minister Greg Hunt had not been informed of the department’s decision, the statement said, but concerns had been relayed to Australia’s ambassador to the United Nations Educational, Scientific and Cultural Organization, or Unesco.

“But as far as I can see, it is in the newspapers every day,” Mr. Markham said. “Pretty much everyone in the world knows there is a problem on the Great Barrier Reef.”

Mr. Markham said he had thought the report would galvanize support for important sites suffering degradation as sea levels and temperatures rise, and as extreme weather damages the environment.

The Great Barrier Reef, which stretches from the tip of northern Queensland more than 1,400 miles southward along Australia’s east coast, has experienced significant coral bleaching over the last year. Bleaching can lead to coral death.

The chapter removed from the report, now published on the website of the Union of Concerned Scientists, warns that Australia is the world’s fourth-largest coal producer and that risks come with plans to expand coal mining and shipping near the reef.

“Its future is at risk, and climate change is the primary long-term threat,” the chapter says.

Australian scientists who reviewed the chapter before the report was published said they were surprised it had been cut.

Ove Hoegh-Guldberg, a director of the Global Change Institute at the University of Queensland, said the report contained nothing new.

“I was naturally a bit disappointed, because the process had not preserved the science,” he said. “And in one sense, if you were trying not to draw attention to the problems on the reef, this would not be the way to do it.”

Prof. Will Steffen of the Climate Change Institute at Australian National University said it was troubling that a government department had succeeded in censoring a global report.

“Australia is the only inhabited continent that is not featured in the report,” he said. “Information is the currency of democracy, and the idea that government officials would exert pressure to censor scientific information on our greatest national treasure is extremely disturbing.”

Australia’s conservative coalition government, in the middle of a re-election campaign, has received little support for its approach to climate change. Prime Minister Malcolm Turnbull did not mention it in a major campaign speech recently and has done little to convince voters that his government believes it is an election issue.

Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organization, or Csiro, is in the middle of a restructuring that includes cutting the number of climate scientists it employs, drawing criticism from scientists at its partner organizations, including NASA.

The inclusion of the Great Barrier Reef in the United Nations report was founded on its significance, Mr. Markham said, adding that references to the island of Tasmania and to Kakadu National Park, in the Northern Territory, had also been removed from the report.

The report does not cover all World Heritage sites; rather, its authors started with about 100 natural and human-made monuments, including Yellowstone National Park and the Statue of Liberty, and winnowed that list to 31 sites in 29 countries.

Terry Hughes, the director of the Center of Excellence for Coral Reef Studies at the Australian Research Council who spent days in April flying over the Great Barrier Reef tracking bleaching and coral mortality rates, said it was astonishing that the reef would be excluded from such a report.

“There is an unprecedented bleaching event underway,” Professor Hughes said. “Climate change and coral bleaching is the single biggest threat to the tourism industry, and the reef itself.”