11/01/2018

New York City Plans To Divest $5bn From Fossil Fuels And Sue Oil Companies

The Guardian - 

Mayor Bill de Blasio: ‘It’s up to the fossil fuel companies whose greed put us in this position to shoulder the cost of making New York safer and more resilient’
Lower Manhattan was hit by a power cut during Superstorm Sandy in 2012. Photograph: Afton Almaraz/Getty Images
New York City is seeking to lead the assault on both climate change and the Trump administration with a plan to divest $5bn from fossil fuels and sue the world’s most powerful oil companies over their contribution to dangerous global warming.
City officials have set a goal of divesting New York’s $189bn pension funds from fossil fuel companies within five years in what they say would be “among the most significant divestment efforts in the world to date”. Currently, New York City’s five pension funds have about $5bn in fossil fuel investments. New York state has already announced it is exploring how to divest from fossil fuels.
“New York City is standing up for future generations by becoming the first major US city to divest our pension funds from fossil fuels,” said Bill de Blasio, New York’s mayor.
“At the same time, we’re bringing the fight against climate change straight to the fossil fuel companies that knew about its effects and intentionally misled the public to protect their profits. As climate change continues to worsen, it’s up to the fossil fuel companies whose greed put us in this position to shoulder the cost of making New York safer and more resilient.”
De Blasio said that the city is taking the five fossil fuel firms – BP, Exxon Mobil, Chevron, ConocoPhillips and Shell – to federal court due to their contribution to climate change.
Court documents state that New York has suffered from flooding and erosion due to climate change and because of looming future threats it is seeking to “shift the costs of protecting the city from climate change impacts back on to the companies that have done nearly all they could to create this existential threat”.
The court filing claims that just 100 fossil fuel producers are responsible for nearly two-thirds of all greenhouse gas emissions since the industrial revolution, with the five targeted companies the largest contributors.
The case will also point to evidence that firms such as Exxon knew of the impact of climate change for decades, only to downplay and even deny this in public. New York’s attorney general, Eric Schneiderman, is investigating Exxon over this alleged deception.
New York was badly rattled by Hurricane Sandy in 2012 and faces costs escalating into the tens of billions of dollars in order to protect low-lying areas such as lower Manhattan and the area around JFK airport from being inundated by further severe storms fueled by rising sea levels and atmospheric warming. De Blasio’s office said climate change is “perhaps the toughest challenge New York City will face in the coming decades”.
New York’s lawsuit echoes a similar effort on the west coast, where two California counties and a city are suing 37 fossil fuel companies for knowingly emitting dangerous levels of greenhouse gases. One of those firms, Exxon, has complained that it has been targeted by a “collection of special interests and opportunistic politicians” as part of a “conspiracy” to force the company to comply with various political objectives.
The legal action and the divestment draw perhaps the starkest dividing line yet between New York and the Trump administration on climate change. Under Trump, the federal government has attempted the withdraw the US from the Paris climate accords, tear up Barack Obama’s signature climate policies and open up vast areas of America’s land and waters to coal, oil and gas interests.
De Blasio and the city comptroller, Scott Stringer, have come under pressure for several years from activists to rid New York’s pension funds of any link to fossil fuels, with some environmentalists claiming the city has been too slow to use its clout to tackle climate change.
Stringer admitted the divestment will be “complex” and will take some time but said the city’s pension funds could promote sustainability while also protecting the retirement of teachers, police officers and other city workers.
“New York City today becomes a capital of the fight against climate change on this planet,” said Bill McKibben, co-founder of climate group 350.org.
“With its communities exceptionally vulnerable to a rising sea, the city is showing the spirit for which it’s famous – it’s not pretending that working with the fossil fuel companies will somehow save the day, but instead standing up to them, in the financial markets and in court.”
Christiana Figueres, former UN climate chief and architect of the Paris climate agreement, added: “The exponential transition toward a fossil-fuel-free economy is unstoppable and local governments have a critical role to play. There is no time to lose.
“It’s therefore extremely encouraging to see NYC step up today to safeguard their city and exercise their role as investors to protect their beneficiaries from climate-risk.”
New York joins cities such as Washington DC and Cape Town in divesting, along with universities such as Stanford in California and Oxford in the UK. The Rockefeller Brothers Fund, notable for its links to the past oil wealth of John D Rockefeller, has also sought to divest.

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China, Moving To Cut Emissions, Halts Production Of 500 Car Models

New York Times - Hiroko Tabuchi

Smog on a main thoroughfare in Harbin, China, in November. Officials are under intense pressure to rein in dangerous air pollution. Tao Zhang/Getty Images
China is suspending the production of more than 500 car models and model versions that do not meet its fuel economy standards, several automakers confirmed Tuesday, the latest move by Beijing to reduce emissions in the world’s largest auto market and take the lead in battling climate change.
The government-affiliated China Vehicle Technology Service Center said that the suspension, effective Jan. 1, would affect both domestic carmakers and foreign joint ventures.
The move was expected to affect a small share of car manufacturing in China, where 28 million vehicles were produced in 2016. China has dozens of small-scale automakers — some producing just a few hundred cars a year — and the central government has tried to consolidate its auto industry, a factor that most likely also played a role in the suspension. Model versions — for example, different combinations of an engine and transmission — are constantly being deregistered.
Cui Dongshu, the secretary general of the China Passenger Car Association, said that the ban would affect at most 1 percent of the Chinese market. But the government’s decision to cite fuel economy in the deregistration of so many versions at the same time is nonetheless a signal of the government’s commitment to fuel economy.
The country, which for years prioritized economic growth over environmental protection and now produces more than a quarter of the world’s human-caused greenhouse gases, has emerged as an unlikely bastion of climate action after President Trump’s rejection of the Paris climate agreement.
Chinese leaders are under intense pressure to rein in dangerous air pollution, a hot-button issue in China, where thick smog has at times forced schools and businesses to temporarily shut down. Late last month, China said it was going ahead with plans to create the world’s largest carbon market, giving Chinese power companies a financial incentive to operate more cleanly.
“They’re sending a signal to everybody — that this is for real,” said Michael Dunne, president of Dunne Automotive, a Hong Kong-based consultancy on China’s clean car market. “This shows their emissions standards have teeth.”
The Chinese government has already become the world’s biggest supporter of electric cars, offering automakers numerous incentives for producing so-called new energy vehicles. Those incentives are set to decrease by 2020, to be replaced by quotas for the number of clean cars automakers must sell. That has spurred global automakers to pick up the pace in their shift toward battery-powered cars.
An assembly line at the FAW-Volkswagen plant in Chengdu, China. The country produced 28 million vehicles in 2016. Goh Chai Hin/Agence France-Presse — Getty Images
By contrast, the United States is considering relaxing tailpipe emissions standards and very nearly killed off a tax credit for electric vehicles during its latest tax overhaul.
The fact that Chinese automakers like the state-run giant Dongfeng Motor Corporation did not appear to be spared “shows that the government is not playing favorites in trying to meet their goals,” said Bruce M. Belzowski, managing director of the Automotive Futures group at the University of Michigan Transportation Research Institute.
The Chinese government had long held back from aggressive emissions standards to allow its own automakers to catch up with the latest clean car technology. But that is changing, with the government setting increasingly stringent tailpipe rules.
The latest development “is a testimony to how quickly their own automakers have evolved,” Mr. Dunne said. “They’re saying: We’re ready to play this game.”
Foreign automakers were still tallying the effect of the suspension on Tuesday. Volkswagen, General Motors, Honda and other foreign automakers in China referred queries on specific numbers to their Asia offices. Rebecca Kiehne of BMW, which runs the BMW Brilliance joint venture in China, said the company was not yet prepared to comment.
Han Tjan, a spokesman for Daimler, said production would not be affected at its Beijing Benz joint venture with the Chinese car manufacturer BAIC Motor Corporation. The only car covered by the suspension was a high-end E-Class model the venture has not manufactured since 2016, he said.
The United States regulates cars by model years, and also approves various versions of each model. Each version may no longer be sold in the new car market if it was built to meet a previous model year’s regulations and the regulations are different for the new model year.
By contrast, China relies on a system of assigning a number to each version of a model. When an automaker tweaks a car’s design to improve its appeal or improve its regulatory compliance, whether annually or at some other interval, the new version receives a new number. China deregistered 553 of these numbers effective Dec. 31.
Global automakers will have no choice but to meet the increasingly stringent government policies in China, said Michelle Krebs, an analyst at the AutoTrader Group.
“The simple fact that China is the biggest market means automakers will be accommodating,” she said.

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More Than Half Of New Norway Car Sales Now Electric Or Hybrid

Reuters - Alister Doyle | Camilla Knudsen

An electric car is charged at a parking lot in Oslo, Norway, June 1, 2017. REUTERS/Ints Kalnins

Summary
  • Norway tops global sales of electric cars
  • Electric, hybrid cars make up 52 pct of 2017 sales
  • Big subsidies have aided shift from fossil fuel cars
OSLO - Sales of electric and hybrid cars exceeded half of new registrations in Norway in 2017, a record aided by generous subsidies that extended the Nordic nation’s lead in a shift from fossil-fuel engines, data showed on Wednesday.
Pure electric cars and hybrids, which have both battery power and a diesel or petrol motor, accounted for 52 percent of all new car sales in 2017 in Norway against 40 percent in 2016, the independent Norwegian Road Federation (OFV) said.
“No one else is close” in terms of a national share of electric cars, OFV chief Oeyvind Solberg Thorsen said. “For the first time we have a fossil fuel market share below 50 percent.”
Norway exempts new electric cars from many taxes and road tolls and owners often get free parking and charging. Norway also generates almost all its electricity from hydropower, so the shift helps to reduce air pollution and climate change.
Last year, the International Energy Agency (IEA) said Norway was far ahead of other nations such as the Netherlands, Sweden, China, France and Britain in electric car sales.



By the IEA yardstick, which excludes hybrid cars which only have a small electric motor that cannot be plugged in, electric car sales in Norway rose to 39 percent in 2017 from 29 in 2016, when the Netherlands was in second on 6.4 percent.
“The shift has gone faster than we’d thought, and the big car makers say they’re going all in to produce non-fossil cars,” Thorsen told Reuters. Norway’s electric car policies contrast with its big offshore oil and gas production.
Christina Bu, head of the Norwegian Electric Vehicle Association which represents owners, said it was too early to reduce incentives for electric cars, noting that parliament has set a goal of phasing out sales of fossil fuel vehicles by 2025.
“It’s an ambitious goal only seven years away,” she told Reuters.
A plan last year by the right-wing government to trim electric car incentives in the nation of 5.3 million people, dubbed a “Tesla Tax”, was dropped in negotiations on the 2018 budget.
Norwegian car sales in 2017 were topped by the Volkswagen Golf, BMWi3, Toyota Rav4 and Tesla Model X. The Tesla is pure electric and others have electric or hybrid versions.
Overall, sales of pure electric cars in Norway rose in 2017 to 21 percent from 16 in 2016.
Sales of diesel cars fell most in 2017, to 23 percent from 31 in 2016. Some regions in Norway have started to charge higher road tolls for diesel cars than for petrol-driven vehicles.

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10/01/2018

BOM Annual Climate Statement Shows 2017 Was Australia's Third-Warmest Year On Record“

ABC News - Kate Doyle

A wet beginning and end of the year bookended a warm, dry winter in 2017. (ABC Open contributor FrancesJones)
 Key Points
  • Third warmest year on record despite no El Nino
  • Seven of the 10 hottest years have occurred since 2005
  • Rainfall 8 per cent above the 1961 to 1990 average, but dry over winter
The Bureau of Meteorology (BOM) has confirmed 2017 was Australia's third-warmest year on record, with temperatures almost a degree above the 1961 to 1990 average.
With a rundown of the year's temperatures, rainfall, climate drivers, major weather events and enough maps to make an atlas, the Annual Climate Statement is a late Christmas present for weather lovers.
In 2017 the main climate drivers, the Indian Ocean Dipole and the El Nino Southern Oscillation, were in neutral for much of the year.
But despite there being no El Nino, usually associated with warm temperatures, 2017 was still the third-warmest national mean temperature on record, at 0.95 degrees above the 1961 to 1990 average.
Karl Braganza, BOM's head of climate monitoring, said the figures showed how much Australia had warmed.
The average daily maximums over 2017 were above the 1961 to 1990 average for most of Australia, especially in south-west Queensland and north-west New South Wales. (Supplied: Bureau of Meteorology)
"We have seen that warming across the land surface temperatures and in the ocean surrounding Australia, so they have both warmed by a similar amount and that's consistent with global warming as well," he said.
Seven of the 10 warmest years on record have been recorded since 2005 and only one year was below the 1961 to 1990 average in the past decade.
"Odds [now] favour warmer-than-average temperatures more often than in the past," Dr Braganza said.


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Exxon Prepares To Sue California Cities, Says They Contradict Themselves On Climate Change

Forbes - John O'Brien

ExxonMobil is apparently planning to sue the California cities and counties that have sued it over climate change, alleging they must be lying in their lawsuits or misleading potential investors in bond offerings. (AP Photo/Matthew Brown)
Some government officials in California are hypocrites pushing a political agenda that involves using private lawyers to sue and demonize ExxonMobil, the company is now arguing in a Texas state court.
On Jan. 8, Exxon took the first step towards suing those who orchestrated climate change lawsuits in California by asking the Tarrant County District Court to allow it to question an assortment of government officials and a Hagens Berman lawyer. The company says those local officials are talking out of both sides of their mouths – blaming Exxon for an impending flooding disaster while not disclosing that alleged threat to possible investors in their bond offerings.
In 2017, the counties of Marin, Santa Cruz and San Mateo and the cities of San Francisco, Oakland, Santa Cruz and Imperial Beach filed suit against dozens of energy companies, including Exxon and 17 other Texas-based businesses, over climate change. The company has previously been targeted by the attorneys general of Massachusetts and New York.
“It is reasonable to infer that the municipalities brought these lawsuits not because of a bona fide belief in any tortious conduct by the defendants or actual damage to their jurisdictions, but instead to coerce ExxonMobil and others operating in the Texas energy sector to adopt policies aligned with those favored by local politicians in California,” attorneys for the company wrote.
In doing so, they must have lied to potential investors in their respective bond offerings, the company claims.
Statements made to potential investors contradict allegations made by the municipalities when they sued the energy industry, the filing says. For example:
  • San Mateo County’s complaint says it is “particularly vulnerable to sea level rise” and that there is a 93% chance the county experiences a “devastating” flood before 2050. However, bond offerings in 2014 and 2016 noted that the county “is unable to predict whether sea-level rise or other impacts of climate change or flooding from a major storm will occur.”
  • Imperial Beach alleged a similar danger from sea level rise, claiming coastal flooding will cause more than $38 million in damages and its economic vulnerability is valued at more than $106 million. However, Exxon says, the city has never warned investors that such disasters await.
  • Marin County alleges a 99% risk it will experience a devastating flood before 2050 in its lawsuit but has not disclosed that to investors in bond offerings, Exxon says.
The company makes similar claims about the lawsuits filed by San Francisco, Santa Cruz city and county and Oakland.
“In 2014 and 2017, San Francisco circulated bond offerings for its Municipal Transportation Agency that do not even contain the words ‘global warming’ or ‘climate change,’” Exxon’s petition says.
“The word ‘flood’ appears only once in these bond offerings – to disclose the absence of ‘insurance policies covering earthquake, flood, environmental pollution or other, similar risks.’”
Exxon goes on to call the municipalities “eager consumers of energy” that emit substantial amounts of greenhouse gases.
Exxon believes 16 individuals possess evidence that would allow it to file a lawsuit that would likely contain a claim for civil conspiracy.
Notable among the group is Matt Pawa, a Hagens Berman attorney instrumental in creating a “playbook” discussed at a conference in La Jolla, CA, and carried out by the AGs of New York and Massachusetts and the California local governments, Exxon says. He represents San Francisco and Oakland in their lawsuits.
Exxon has also been locked in a dispute with New York AG Eric Schneiderman and Massachusetts AG Maura Healey. Those AGs have issued subpoenas to the company as they investigate whether it misled investors about its impact on climate change.
A recent Times Union article showed that Schneiderman invested between $50,000 to $75,000 in Vanguard Energy ETF. That fund’s biggest holding is Exxon.
“A collection of special interests and opportunistic politicians are abusing law enforcement authority and legal process to impose their viewpoint on climate change,” Exxon says.
“This conspiracy emerged out of frustration in New York, Massachusetts and California with voters in other parts of the country and with the federal government for failing to adopt their preferred policies on climate change.
“But rather than focusing their efforts in the marketplace of ideas and adopting a strategy of persuasion, the members of this conspiracy chose to advance their political objectives by imposing unlawful burdens on perceived political opponents.”
Exxon filed suit in Texas federal court in response to the subpoenas issued by Schneiderman and Healey. It has since been transferred to New York and remains pending.
“The Court is uncertain if it is common practice for attorneys general to begin to investigate a company after reading an article that accuses a company of possibly committing wrongdoing decades ago,” U.S. District Judge Ed Kinkeade wrote when he sent the suit to New York because that’s where Schneiderman held a press conference to announce his investigation.
“What the Court does know is that Exxon has publicly acknowledged since 2006 the possible significant risks to society and ecosystems from rising greenhouse gas emissions, yet the attorneys general have only recently felt compelled to look further into Exxon’s documents from the last 40 years to see if Exxon knew more than it shared with the public and investors about climate change.”
In addition to Pawa, Exxon seeks to depose: John Beiers, San Mateo County Counsel; John Maltbie, San Mateo County Manager; Jennifer Lyon, city attorney for Imperial Beach; Andy Hall, city manager of Imperial Beach; Serge Dedina, mayor of Imperial Beach; Brian Washington, county counsel of Marin County; Matthew Hymel, county administrator of Marin County; Barbara Parker, city attorney of Oakland; Sabrina Landreth, city administrator of Oakland; Dennis Herrera, city attorney of San Francisco; Edward Reiskin, director of transportation of San Francisco’s MTA; Dana McRae, county counsel for Santa Cruz; Carlos Palacios, assistant county administrative officer of Santa Cruz; Anthony Condotti, city attorney for Santa Cruz; and Martin Bernal, city manager of Santa Cruz.

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09/01/2018

Antarctica Is Melting From Below—And It's Getting Worse

Newsweek - 



Antarctica’s ice shelves are melting from warming ocean waters below—even during seasons when snowfall on top of them is increasing. This strange paradox could worsen from the natural climate phenomenon El Niño, according to a study published Monday in Nature Geoscience. Based on 23 years of satellite data from the West Antarctic ice shelves, the study revealed that a strong El Niño event causes the shelves to lose more ice from melting beneath than they gain back from snowfall on top of it.
Sea ice floats as seen from NASA's Operation IceBridge research aircraft in the Antarctic Peninsula region, on November 4, 2017, above Antarctica. Getty
“I was expecting to see an overall reduction in height as a consequence of mass loss, but it turns out that height increases,” Fernando Paolo, the study’s lead author, said in a statement. Paolo conducted the study while he was a graduate student and postdoc at Scripps Institution of Oceanography at the University of California San Diego.
El Niño causes snowfall to increase, especially in the Amundsen Sea sector. Though the snowfall increases the actual height of this ice shelf, El Niño events cause wind patterns in Antarctica to push warmer ocean waters towards the ice shelf, which results in the basal melting.
The satellite data from 1994 to 2017 revealed the height of the ice decreased by eight inches per year overall from ocean melting, according to the study. But during the El Niño event in 1997 and 1998, the height increased by 10 inches. The fresh snowfall, however, is much less dense than the solid ice that makes up most of the shelf. The mass, which is the most important measurement in terms of sea level rise, was decreasing although the height increased during the event. The extra snowpack was minimal compared to how much solid ice melted from below. Ice shelves lost five times more ice from below than they gained back from fresh snowfall.
Sea ice is viewed aboard NASA's research aircraft in the Antarctic Peninsula region, on November 3, 2017, above Antarctica. Getty 
El Niño events are expected to worsen and intensify in the wake of climate change, according to Paolo, now a postdoctoral scholar at NASA’s Jet Propulsion Laboratory. El Niño could affect how quickly ice shelves melt, this study reveals. That factor needs to be integrated into sea level rise models. “All that should be taken into account when we run our models to predict future behaviors of the ice shelf and the ice sheet as well,” Paolo told Newsweek.
El Niño and La Niña are the two phases of the climate cycle called El Niño—Southern Oscillation (ENSO). The cycle is influenced by the tropical Pacific waters’ temperatures, which alternate between warmer-than-average during El Niño and cooler-than-average during La Niña.
Satellite records over two decades allowed researchers to look at the processes that affect ice shelves, which helps scientists better understand how ice sheets may melt in the future. Understanding the processes behind the melting of ice shelves could help pinpoint how soon and how much sea levels will rise. Ice shelves don’t cause sea level rise on their own. Rather, the ice sheets they hold back from slipping and melting into ocean water hold the fate of coastal communities around the world in their icy grip. Ice shelves, Paolo described, function like an ice cube.
Ice floats near the coast of west Antarctica as viewed from a window of a NASA Operation IceBridge airplane on October 28, 2016, in-flight over Antarctica. Getty 
The ice shelves are "already floating in the ocean, therefore the mass that is lost by the ice shelf does not contribute to sea level rise,” he said. “It’s like having an ice cube [in] a drink. If you let the ice cube melt, the level of the drink will not change.” The ice shelf, rather, plays an “important role in controlling the speed at which these glaciers discharge ice.”
Ice shelves are already vulnerable to calving off large ice chunks. Last July, an iceberg the size of Delaware broke off the Larsen C ice shelf. How those ice shelves work with the ice sheets and glaciers are what directly relates to making more precise sea level projections. Helen Fricker, Paolo's Ph.D. adviser at the time of the study and glaciologist at Scripps, said in a statement: "The holy grail of all of this work is improving sea level rise projections."

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Global Warming’s Toll On Coral Reefs: As If They’re ‘Ravaged By War’

New York Times - Kendra Pierre-Louis | Brad Plumer

A researcher examined bleached coral at Zenith Reef, in the northern section of the Great Barrier Reef, in November 2016. Andreas Dietzel/ARC Centre of Excellence for Coral Reef Studies
Before we call rockfish, shrimp and crab “dinner,” some of these species call coral reefs “home.” But those reefs, home to a quarter of all marine fish species, are now increasingly threatened as rising ocean temperatures accelerate a phenomenon known as coral bleaching.
Large-scale coral bleaching events, in which reefs become extremely fragile, were virtually unheard-of before the 1980s. But in the years since, according to a study published Thursday in the journal Science, the frequency of coral bleaching has increased to the point that reefs no longer have sufficient recovery time between severe episodes.
Jelle Atema, a professor of biology at the Boston University Marine Program who was not involved in the study, said the effects of more frequent bleaching events were very difficult to predict because of the complex networks of dependencies within reefs. But he said they could be devastating.
An aerial view of bleaching coral off the Australian coast in March 2016. Terry Hughes/ARC Centre of Excellence for Coral Reef Studies
“When coral dies, it affects the shelter and food that sustain fish, lobsters, shellfish, worms, etc. The same happens in a rain forest. When the trees die, the animals and plants that have developed over millennia die with them,” he said, before adding an analogy. “When a country is ravaged by war, people die and migrate.”
During bleaching events, overheated seawater causes corals to part ways with symbiotic plantlike organisms called zooxanthella that live inside of them. In addition to giving coral reefs their bright colors, zooxanthella also provide corals with oxygen, waste filtration, and up to 90 percent of their energy. Absent zooxanthella, corals not only take on a ghostly pallor, hence the term bleaching, but they are also more susceptible to death.
In theory, coral reefs can recover from even a severe bleaching event. Some of the coral will die off from increased disease susceptibility, but once ocean temperatures drop again, many of the corals will start growing back.
But that’s only if they’re given enough time.
Typically, it takes 10 to 15 years for the fastest-growing corals to recover after a severe bleaching event. Larger corals that provide shelter for bigger fish can take even longer to grow back.
As bleaching events become more frequent, reefs are unlikely to get that needed reprieve. Earth’s average temperature has increased 1 degree Celsius, or 1.8 degrees Fahrenheit, above preindustrial levels, and the median time between severe bleaching events is now just six years, the Science study found.
Case in point: The Scott Reef, 180 miles off the coast of Northwestern Australia, had over the past few years finally begun recovering from a major bleaching event in 1998, with the fastest-growing corals inhabiting much of their earlier territory. But the area was hit by bleaching again in 2016, causing widespread mortality.
Before 1982-3, mass bleaching events across wide areas were nonexistent. That year, reefs across the Tropical Eastern Pacific exposed to warm El Niño year waters bleached. Coral reefs in Costa Rica, Panama and Colombia experienced 70 to 90 percent mortality. Most reefs in the Galápagos Islands, the cradle of Darwin’s theory of evolution, experienced 95 percent mortality.
While many mass bleachings were prompted by El Niño events, which tends to warm Pacific Ocean temperatures, the bleaching event that hit the Great Barrier Reef in 2017 — the reef’s first back-to-back bleaching — occurred at the beginning of a La Niña event, when ocean waters should have been cooler. It’s a sign that global warming is steadily pushing up ocean temperatures even in cooler years.
A blenny on bleached coral. Reefs are home to about a quarter of all marine species. Greg Torda/ARC Centre of Excellence for Coral Reef Studies
“La Niña periods today are actually warmer than El Niño periods were 40 years ago,” said Terry Hughes, a senior researcher who specializes in coral reefs at James Cook University in Australia and the lead author of the Science study.
“Coral bleaching is caused by global warming full stop,” Dr. Hughes said. “It’s not due to El Niño. We’ve had thousands of El Niño prior to 1983, none of them caused bleaching. Bleaching is caused by the rising baseline temperatures due to anthropogenic global warming.”
Scientists have long warned that the effects of climate change will not necessarily progress in a linear way as the planet warms. As Earth crosses certain key temperature thresholds, severe and far-reaching changes can unfold relatively rapidly, such as the collapse of ice sheets or the die-off of key ecosystems.
All evidence suggests that bleaching will only get more and more frequent as the Earth continues to warm. By midcentury, climate models suggest, most reefs will experience the sort of heat associated with severe bleaching every year.
If corals can’t adapt quickly enough, “we could be looking at the effective loss of most of the world’s coral reefs,” said Mark Eakin, an oceanographer who is coordinator of the Coral Reef Watch project at the United States National Oceanographic and Atmospheric Administration.
The Great Barrier Reef had two back-to-back bleaching events that killed just about half of the corals along the length of the barrier reef. This means half are still alive. Those corals are the source of larvae that spawn future generations, which means that the reef moving forward will have a distinctly different character than it had two years before the bleaching event.
“The ecological effect of more and more bleachings is that it’s changing the mix of species in favor of the tougher corals that can survive bleaching events and in terms of the corals that bounce back the quickest,” said Dr. Hughes. “It’s changing the whole ecology of the reefs.”
There are a few things that can help make reefs more resilient to bleaching. Humans can limit fertilizer and sewage runoff that damage coral. They can avoid overfishing key herbivores like the rabbitfish that nurture the reefs by clearing away excessive algae.
A sea turtle in the Indian Ocean amid coral that succumbed to a 2016 bleaching event. Kristen Brown/ARC Centre of Excellence for Coral Reef Studies
Some researchers are experimenting with even more radical techniques, such as trying to breed coral that can thrive in warmer temperatures, or looking at ways to pump cooler water into reefs to protect the coral from overheating, or even placing giant “shade cloths” over reefs.
Some of these ideas are admittedly wild, Dr. Eakin said, and none of them can ever be a substitute for reducing greenhouse gas emissions. “We can’t act as if we can keep emitting carbon dioxide into the atmosphere and just by tinkering around with corals in a lab we’re going to solve the problem,” he said.
But given that frequent bleaching is already underway, and given that at least half a degree of additional global warming appears inevitable, coral researchers are desperate for new ideas.
“We’ve got to start taking steps that we haven’t thought about before — even if they sound absolutely crazy,” Dr. Eakin said. “Because the stuff we thought made sense will no longer work.”

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