OCEAN ACIDIFICATION: Emissions from burning fossil fuels impacting ocean ecosystems

The oceans are a natural carbon sink, so as we burn more fossil fuels and release more carbon dioxide into the atmosphere, ocean pH drops, and oceans become more acidic. As a result, ocean ecosystems are impacted, because calcifying organisms find it harder to exist in these increasingly acidic conditions, because “as the water naturally absorbs carbon dioxide from the air, it forms carbonic acid, [and] the acid then mops up calcium carbonate, a substance normally plentiful in the oceans that sea creatures use to make the protective shells that they need to survive.” Certainly, it’s time for George Will to explain how and why the scientific majority has gotten ocean acidification wrong in his Washington Post column (like he did with global warming).

A clip from ABC News discussing ocean acidification with Sylvia Earle

From the guardian.co.uk:

Human pollution is turning the seas into acid so quickly that the coming decades will recreate conditions not seen on Earth since the time of the dinosaurs, scientists will warn today.

The rapid acidification is caused by the massive amounts of carbon dioxide belched from chimneys and exhausts that dissolve in the ocean. The chemical change is placing “unprecedented” pressure on marine life such as shellfish and lobsters and could cause widespread extinctions, the experts say.

. . .

Ken Caldeira, an expert on ocean acidification at the Carnegie Institution in California, will tell the conference that the next few decades could produce “profound” changes in the oceans. He will say: “The choice to continue emitting carbon dioxide means that we will be an agent of biological change of a force and magnitude exceeded only by the causes of the great mass extinction events. If we do not cut carbon dioxide emissions deeply and soon, the consequences of ocean acidification will stand out against the broad reaches of geologic time. Those consequences will remain embedded in the geologic record as testimony from a civilisation that had the wisdom to develop high technology, but did not develop the wisdom to use it wisely.”

Other experts will report that acidification is already affecting marine life in the Arctic and Antarctic. They will also discuss a bizarre finding that acid waters carry sound more efficiently, so the ocean will be a much noisier place in future.

From Science Daily:

The impact on reefs is a consequence of both ocean acidification caused by the absorption of carbon dioxide into seawater and rising water temperatures. Previous studies have shown that rising carbon dioxide will slow coral growth, but this is the first study to show that coral reefs can be expected to start dissolving just about everywhere in just a few decades, unless carbon dioxide emissions are cut deeply and soon.

“Globally, each second, we dump over 1000 tons of carbon dioxide into the atmosphere and, each second, about 300 tons of that carbon dioxide is going into the oceans,” said co-author Ken Caldeira of the Carnegie Institution’s Department of Global Ecology, testifying to the U.S. House of Representatives Subcommittee on Insular Affairs, Oceans and Wildlife of the Committee on Natural Resources on February 25, 2009. “We can say with a high degree of certainty that all of this CO2 will make the oceans more acidic – that is simple chemistry taught to freshman college students.”

The study was designed determine the impact of this acidification on coral reefs. The research team, consisting of Jacob Silverman, Caldeira, and Long Cao of the Carnegie Institution as well as Boaz Lazar and Jonathan Erez from The Hebrew University of Jerusalem, used field data from coral reefs to determine the effects of temperature and water chemistry on coral calcification rates. Armed with this information, they plugged the data into a computer model that calculated global seawater temperature and chemistry at different atmospheric levels of CO2 ranging from the pre-industrial value of 280 ppm (parts per million) to 750 ppm. The current atmospheric concentration is over 380 ppm, and is rapidly rising due to human-caused emissions, primarily through the burning of fossil fuels.

Based on the model results for more than 9,000 reef locations, the researchers determined that at the highest concentration studied, 750 ppm, acidification of seawater would reduce calcification rates of three quarters of the world’s reefs to less than 20% of pre-industrial rates. Field studies suggest that at such low rates, coral growth would not be able to keep up with dissolution and other natural as well as manmade destructive processes attacking reefs.