David Doubilet/National Geographic
From National Geographic: Our waters have borne the brunt of global-warming for decades, but dying corals, extreme weather, and plummeting fish stocks are signs that it can handle no more. And people are already experiencing direct consequences, such as more extreme weather events, says a new report by the International Union for Conservation of Nature.
The oceans, which have borne the brunt of most of global warming, have finally hit their limit as dying corals and plummeting fish stocks signal that the seas are at a dangerous tipping point, according to the broadest ever look at the issue. And people are already experiencing direct consequences, such as more extreme weather events, including hurricanes, says the report, released by the International Union for Conservation of Nature.
“We all know the oceans sustain this planet,” says Inger Andersen, IUCN’s director general, “yet we are making the oceans sick.”
Since 1970, global waters have been a “powerful ally” against global warming, absorbing 93 percent of the carbon dioxide released by human activities. (See “Ocean Warming Faster Now Than in 10,000 Years.”)
“Without this oceanic buffer, global temperature rises would have gone much, much speedier,” Andersen said Monday at the IUCN World Conservation Congress.
Now, as global warming continues apace, the ocean will continue to warm by between 1 to 4 degrees Celsius by 2100, Andersen says. “In an ecological timescale, 2100 is tomorrow.”
Eighty scientists from 12 countries contributed to the “most comprehensive, most systematic study we’ve ever undertaken on the warming of the oceans,” Laffoley says.
“We’ve looked from microbes to whales, from pole to pole, we’ve looked at all the major ecosystems, including the deep ocean,” he says. (See “Oceans Are Losing Oxygen—and Becoming More Hostile to Life.”)
One of the most worrying phenomena is that entire species populations—such as plankton, jellyfish, turtles, and seabirds—are moving toward the poles by up to 10 degrees latitude, taking up residence in waters previously too cold to support them. That’s five times faster than land animals are migrating north.
In particular, fish species moving out of their known range could destabilize the world’s fisheries. In Southeast Asia, for instance, as fish leave their homes, marine fisheries may fall by up to 30 percent by 2050, the report says. And in East Africa and parts of the Indian Ocean, where warming has already killed coral reefs, fish species have also died, taking away many fishermen’s livelihoods. (See “As Oceans Heat Up, a Race to Save World’s Coral Reefs.”)
The outlook is particularly bleak for coral reefs, also a mainstay of ecotourism for many countries—some areas have already lost up to half of their reefs, according to the report.
The latest models predict that by 2050, warmer oceans will bleach nearly all the world’s reefs. So-called bleaching which occurs when a coral’s symbiotic algae—the cause of their vibrant colors—depart en masse, leaving the coral to likely starve. (Related: “93 Percent of the Great Barrier Reef Is Suffering.”)
People who live near or interact with the ocean could also be at increased risk of illness, as warmer oceans quickly spreads pathogens, such as cholera-carrying bacteria and algal blooms that can cause neurological diseases.
And as the ocean warms, so will severe weather, such as hurricanes and typhoons, says Andersen, who noted the rare double hurricanes that recently skirted Hawaii.
According to the report, the number of severe hurricanes have risen by up to 30 percent per degree of global warming, as storms feed on warm water. El Niño, the periodic warming of water in the Pacific Ocean, has also intensified over the past two decades.
So “how are we going to stop going to hell in a handbasket?” asks Greg Stone, executive vice president at the nonprofit organization Conservation International and a marine expert.
He suggests treating the ocean like a sick patient that has a temperature. To lower the temperature, that requires stopping polluting the atmosphere with carbon—of course, no easy task.
Another solution, however, is creating marine protected areas—in essence, “telling the patient to rest. Then the immune system has a chance of fighting,” says Stone, who was not directly involved with the new report.
“There’s good news on that front,” he adds. Just this week, President Obama quadrupled the size of Hawaii’s Papahānaumokuākea Marine National Monument. The no-fishing zone is now 582,578 square miles, an area larger than all the national parks combined.
The scientists also offered recommendations, such as planning for the imminent blow to regional economies. For instance, if kelp forests die off—which is already taking place—countries need to know what will happen to their fisheries.
Difficult as all of this may sound, it’s on us, says Carl Gustaf Lundin, director of the Global Marine and Polar Programme.
“There’s no doubt in all our minds that we’re the cause of this,” he says.
“We know what the solutions are—and we need to get on with it.”
Original story with photographs on the National Geographic website
Report: Soaring ocean temperature is ‘greatest hidden challenge of our generation’
The oceans have already sucked up an enormous amount of heat due to escalating greenhouse gas emissions, affecting marine species from microbes to whales, according to a report involving the work of 80 scientists from a dozen countries. The profound changes underway in the oceans are starting to impact people, it states.
Red alert: Fish under threat from ocean oxygen depletion
A new study shows that oxygen levels in oceans have fallen 2% in 50 years due to climate change, which threatens future fish stocks and the habitat and behaviour of marine life. Related: Amitav Ghosh warns that the Bay of Bengal’s depleted fish stocks and huge dead zone signal a tipping point.
Oceans to have more plastic than fish by 2050: Report
The world’s oceans may have more plastic debris than fish by the year 2050, according to a report produced by the Ellen MacArthur Foundation and published by the World Economic Forum. The study found that a whopping 32 percent of all plastic packaging escapes collection systems and finds its way into natural ecosystems, including the oceans. Currently, 8 million tonnes of plastic end up in the ocean each year – the equivalent of a dump truck of plastic rubbish every minute.
Speech by representatives of indigenous fisher folk at the first UN conference on oceans
Friends of Marine Life (FML), is a Kerala-based organisation that specialises in seabed ecosystem studies and also helps promote sustainable fishing. Three of it’s members, who hail from the state’s indigenous fishing community, the Mukkuva, were recently invited the first UN conference on the world’s oceans. The text of speeches they delivered at the conference.