CO2 Threats to World´s Oceans Rising, Scientists Warn

Monaco Declaration on Ocean Acidification Cites Links to Climate Change

Marine scientists warn that coral reefs are in danger from climate changes and ocean acidification. Most ocean regions could become inhospitable to coral reefs by 2050 if atmospheric CO2 levels continue to increase, they say. (Photo: J. Ford/IAEA)

In Monaco, scientists at the IAEA Marine Environment Laboratories (IAEA-MEL) have joined more than 150 experts from 26 countries calling for urgent actions to halt rising levels of acidity in the world´s oceans.

"It is the other CO2 problem that must be grappled with alongside climate change. Reining in this double threat, caused by our dependence on fossil fuels, is the challenge of the century," the marine scientists say.

The leading scientists joined to back the Monaco Declaration on Ocean Acidification, directed at government leaders worldwide. The Declaration emphasizes that levels of acidity in oceans are accelerating and that the negative socio-economic impacts can only be limited by cutting back on the amounts of greenhouse gases released into the atmosphere.

"The chemistry is so fundamental and changes so rapid and severe that impacts on organisms appear unavoidable," said James Orr, an IAEA research scientist at MEL´s Radiometrics Laboratory. "The questions are now how bad will it be and how soon will it happen."

Dr. Orr chaired the Second International Symposium on the Ocean in a High-CO2 World, held in October 2008, where scientists presented reports that form the Declaration´s basis. The Symposium summarized the state of the science and priorities for future research, while the Monaco Declaration implores political leaders to launch urgent actions to limit the source of the problem, he says.

Prince Albert II of Monaco, whose enviornmental foundation financially supported the 2008 ocean symposium, voiced support for the Declaration, and cited its importance in light of the forthcoming UN Climate Change Conference in Copenhagen in December 2009.


Facts from the Declaration: The ocean absorbs CO2 from the atmosphere at a rate of more than 20 million tons per day, thus removing one-fourth of the anthropogenic CO2 emitted to the atmosphere each year and reducing the climate-change impacts of this greenhouse gas. However, when CO2 dissolves in seawater, it forms carbonic acid. As this "ocean acidification" continues, it decreases both ocean pH and the concentration of carbonate ion, the basic building block of the shells and skeletons of many marine organisms.

The rate of current acidification is much more rapid that past natural changes. Surface ocean pH has already dropped by 0.1 units since the beginning of the Industrial Revolution. This rate of acidification has not been experienced by marine organisms, including reef-building corals, for many millions of years. The future chemical changes that will occur in the ocean as a result of increasing atmospheric CO2 are highly predictable.

According to the experts, ocean acidification may render most regions of the ocean inhospitable to coral reefs by 2050 if atmospheric CO2 levels continue to increase. It could lead to substantial changes in commercial fish stocks, threatening food security for millions of people as well as the multi-billion dollar fishing industry.

The IAEA Marine Environment Laboratories (IAEA-MEL) in Monaco were established in 1961 as today are part of the IAEA Department of Nuclear Sciences and Applications. They are the only marine laboratories within the UN system.

Last update: 24 February 2015