tagged w/ Co2 saturation
-
The icy Arctic waters around Norway's archipelago of Svalbard may seem pristine and clear, but like the rest of the world's oceans they are facing the threat of growing acidity.
Oceans have always absorbed part of the carbon dioxide, or C02, present in the air, which in turn makes them acid. But with CO2 levels soaring, the scientific community is getting worried about acidification harming marine life.
Off the coast of Ny-Aalesund, a tiny coal mine village turned scientific outpost just 1,200 kilometres (745 miles) from the North Pole, researchers from nine European countries conducted in July an unprecedented effort to analyse the phenomenon.
To do so, they submerged nine tubes, each weighing two tonnes and the height of two double-decker busses, in the icy waters of the remote fjord framed by snow-capped mountains.
They then injected the water-tight tubes, called mesocosms, with CO2, to reproduce sea life under different acidity levels expected from now until 2150 with the aim of studying the potentially disastrous effects of acidification on marine life.
"It's here in the Arctic that the ocean will become corrosive the fastest," Jean-Pierre Gattuso, with France's National Center for Scientific Research, said, explaining why the researchers chose to turn these waters thick with icy slush into a laboratory.
The threat to the world's oceans is not so much the absolute concentration of acidity, but rather the pace at which it is changing, Gattuso explained, pointing out that "cold water swallow up gas faster than hot or temperate water."
Oceans absorb more than a quarter of the CO2 emitted by humans, which in one way is fortunate since this natural absorption mitigates the impact the gas has on the climate.
However the soaring levels of man-made CO2 in the atmosphere are proving devastating to the oceans themselves: since the beginning of the industrial era they have become 30 percent more acidic, reaching an acidity peak not seen in at least 55 million years, scientists say.
And with no sign of CO2 emissions slowing down, ocean acidification will likely keep increasing in the decades to come.
This is especially worrisome since higher acidity levels have been shown to sharply slow calcification in corals, shellfish and other species.
Corals, a source of rich biodiversity that prevents land area from being submerged and draws much-needed tourists to some of the world's poorest corners, might thus have trouble shaping their skeletons, while shellfish could lose their shells.
Adaptation is less likely
Ulf Riebesell, a German oceanographer, said not all sea creatures were equal in their ability to adapt to their increasingly acid environment.
"For micro-organisims which have generation times of a few days, adaptation may happen during the next 100 years or so as the ocean continues to acidify to critical levels," explained the researcher from the IFM-Geomar centre, braving glacial winds in a bright yellow padded windbreaker and a woolen hat.
But for organisms with long life spans, like corals, "adaptation is much less likely because they need so many generations to change their genetic set-up," Riebesell said.
Scientists caution the current frantic increase of seawater acidity is already causing serious problems for the pteropod, a sort of sea snail vital for the Arctic food chain.
The tiny, translucent mollusc could end up naked in the near future, unable to shape its shell in an increasingly acid environment, explained Jan Buedenbender, another German researcher from the IFM-Geomar institute. This could have far-reaching consequences, he warned.
"They're a key species for the Arctic food system because they're feeding on very small particles and on phytoplankton, and they're getting quite big and really big animals like whales and birds and fish can feed on them," he explained.
They are also key because their shell contributes to fighting climate change, since it helps the sea snail sink to the bottom when it dies, dragging down all the CO2 ingested over its short lifespan.
By doing so "they're helping the ocean take up more CO2," Buedenbender said. There is still a chance to save species like the pteropod, according to Iris Menn, a marine biologist with Greenpeace which shipped the giant test-tubes up to Svalbard.
But there is no easy solution. To make a difference, industrialised countries will have to slash their CO2 emissions by 40 percent by 2020, she said.
"We can't stop the trend anyway. We will have a high level of acidity in the water no matter what," she said.
"But what we can do is stop CO2 emissions, so the effect will be reduced."The icy Arctic waters around Norway's archipelago of Svalbard may seem pristine... more
-
-
Ministers and officials from 70 nations will gather in Indonesia on Monday for talks on protecting the world's oceans and to help set the stage for climate change talks in December.
The five-day World Ocean Conference in Manado city is being touted as a first-of-a-kind meeting on the oceans' role in mitigating climate change and on the consequences of higher temperatures such as rising seas, extinctions and food shortages.
Environment, fisheries and resources ministers are expected to agree a declaration aimed at influencing the direction of the Copenhagen talks scheduled for year end, where nations will gather to hammer out the successor to the expiring Kyoto protocol.
Organisers say they hope to expand the scope of any future climate change agreement to encompass marine environments, on which hundreds of millions of people rely for their livelihoods.
"The conference will be non-binding but it is the highest political level ocean conference done so far," said Indroyono Soesilo, the Indonesian official in charge of organising the event on Sulawesi island.
"If we are able to put oceans into world climate change policies it will be a success for us because it has never happened before.
"Because of global warming we will have sea level rises that will make some island nations disappear, so let's do something about that."
The sidelines of the conference will also see the launch of an international plan to save the Coral Triangle, an underwater ecosystem in Southeast Asia that is half the size of the United States and has been compared to the Amazon rainforest in its biodiversity.
Leaders from the six Coral Triangle Initiative nations -- Indonesia, the Philippines, Malaysia, East Timor, Papua New Guinea and the Solomon Islands -- will sign a joint plan to protect the region, home to more than half the world's coral reefs.
But while organisers express optimism over the meeting, scientists say knowledge about the oceans is so limited that not much is known about how they will behave under the influence of climate change or the role they can play in absorbing carbon.
The boosting of ocean research and agreements on international sharing of data are expected to be a part of any conference declaration.
"If you talk about marine carbon issues it's still a long way to go," The Nature Conservancy's Coral Triangle Centre head Abdul Halim said.
"Unless you have at least basic scientific evidence to support your argument it's really difficult for people to argue about."
The conference comes amid a slew of gloomy studies on the possible effects of global warming.
A report in the science journal Nature last month found catastrophic sea level rises of up to three metres are a "distinct possibility" within the next century.
end of excerptMinisters and officials from 70 nations will gather in Indonesia on Monday for talks... more
-
-
In the year 1750, over 98 percent of coral reefs (magenta dots) grew in optimal conditions with aragonite saturation greater than 3.5 (blue colors). Such water is rapidly disappearing and will be gone in several decades if current carbon dioxide emission trends continue. Atmospheric CO2 levels are 280 ppm and 550 ppm for years 1750 and 2050, respectively.
_______________
As a child I never would have thought that the Great Barrier Reef of all places would have the possibility of becoming extinct. I truly do hope this report is wrong, but based on the fact that we humans will more than likely do nothing but continue to argue about this instead of really doing something, I'm beginning to think it is right. And yes, we can do something about it.In the year 1750, over 98 percent of coral reefs (magenta dots) grew in optimal... more
-
