In the past decade, research has revealed a wide range of organism responses to ocean acidification – the decline of seawater pH due to an uptake of man-made carbon dioxide (CO₂) by the ocean. Laboratory and field experiments have focused primarily on individual species. Their responses to ocean acidification have mostly been studied in short-term experiments. 

But how do complex biological communities react to ocean acidification? Are they able to adapt to new conditions when exposed over long periods? To address these questions, long-lasting experiments on natural communities are urgently needed. "With the modified seagoing experimental platform, KOSMOS, we are now able to conduct the first long-term mesocosm experiment in the natural environment", Ulf Riebesell points out. Riebesell is professor for biological oceanography at GEOMAR Helmholtz Centre for Ocean Research Kiel. He coordinates the BIOACID project and the upcoming mesocosm experiments.

Mr. WHITEHOUSE. Mr. President, there are many signs of the fundamental, measurable changes we are causing in the Earth's climate, mainly through our large-scale emission of carbon dioxide from fossil fuels. These are irreversible changes, at least in the short run, so we should take them very seriously.

Over the last 250 years, the global annual average concentration of carbon dioxide in the atmosphere has increased from 280 parts per million to 390 parts per million. That is a 30-percent increase. We have recent direct measurements that the carbon dioxide concentration increased by 15 percent since 1980 when it was 339. In 1980 it was 339 and now it is 390. That is just a dozen years in which the concentration of CO2 in our atmosphere has increased by more than 50 parts per million. Fifty parts per million is a big shift if one is not aware of the scales we are talking about here. For 8,000 centuries--800,000 years--longer than homo sapiens have existed on the face of the Earth, we can measure that the carbon concentration in the atmosphere has fluctuated between 170 and 300 parts per million. A total range of 130 parts per million has been the total range for 8,000 centuries. We are now outside of that range up to 390, and we have moved 50 points since 1980, in a number of decades. So the consequences are going to be profound, and perhaps no consequence of that carbon pollution will be as profound as the increasing acidification of the world's oceans.

The ocean plays an important role in regulating the amount of carbon dioxide in the atmosphere. As atmospheric concentrations of carbon dioxide rise (see the Atmospheric Concentrations of Greenhouse Gases indicator on p. 16), the ocean absorbs more carbon dioxide. Because of the slow mixing time between surface waters and deeper waters, it can take hundreds to thousands of years to establish this balance. Over the past 250 years, oceans have absorbed approximately 40 percent of the carbon dioxide produced by human activities.

Remember what it’s like to hold your breath, your lungs demanding fresh air with increasing urgency? That awful sensation isn’t about lack of oxygen, but is a signal of a dangerous carbon dioxide level. This same CO2 is swiftly changing the chemistry in the earth’s oceans at a rate that would kill you if it were happening inside your own body.

PORT ANGELES — It would take a global reduction in carbon dioxide emissions to reverse the effects of ocean acidification, members of the Clallam County Marine Resources Committee told county commissioners Monday. But there are ways to help at the local and state level — pollution control, a reduction in stormwater runoff and investment in more water monitors — to protect shellfish and other species from potentially lethal changes in ocean chemistry, committee members Ed Bowlby and Andrew Shogren said. “We have to tackle the global aspect, but when possible, when appropriate, to try to tackle it locally to mitigate this onslaught that we can't do anything about,” Bowlby said. “That's a different aspect. That's going to keep occurring. “But we can start trying to minimize local contributions within the watershed, the stormwater runoffs, that can cause local ocean acidification.”