Carbon dioxide in world’s oceans may threaten many marine species - UN

The world’s oceans are absorbing an unprecedented amount of carbon dioxide (CO2), increasing their acidity and possibly threatening the long-term survival of many marine species, including corals, shellfish and phytoplankton, according to a report released today on a United Nations-sponsored symposium.

This development in turn could disrupt marine food chains and alter ocean biogeochemistry in ways that are not yet understood or predictable, according to the research presented at the symposium organized by the Intergovernmental Oceanographic Commission of the UN Educational, Scientific and Cultural Organization (UNESCO) and the International Council for Science’s Committee on Oceanic Research.

Symposium participants found that by the middle of this century, the accumulating burden of CO2 entering the ocean will lead to changes in acidity of the upper layers that are three times greater in magnitude and 100 times faster than those experienced between ice ages. Such dramatic changes have not been observed for more than 20 million years of earth’s history, the meeting concluded.

Concluding that changes are clearly underway and their effects may be large and may seriously destabilize marine ecosystems, the report signalled the need for more investigation and identified research priorities in a bid to increase understanding of the consequences and to allow for more informed policy decisions in this area.

The symposium brought together scientists from the world’s leading oceanographic institutions to develop research priorities to study these future effects. The experts also discussed potential environmental consequences of proposals to use the ocean to sequester excess atmospheric CO2, which is one of the most important greenhouse gases.

According to research led by Christopher Sabine of the United States National Oceanographic and Atmospheric Administration (NOAA), the ocean has taken up approximately 120 billion tons of carbon generated by human activities since 1800. Some 20 million to 25 million tons of CO2 are being are being added to the oceans each day, UNESCO said.