Fish Guidance Systems

Oceans at risk from effects of CO2

Twenty-two leading scientists have collaborated in a report published in a special section of Science journal. The report, 'Contrasting futures for ocean and society from different anthropogenic CO2 emission scenarios' explains that although the ocean moderates anthropogenic change, this has great impacts on its fundamental physics and chemistry, with important consequences for ecosystems and people.

The scientists conclude that the oceans are at risk from a combination of issues resulting from the burning of fossil fuels. The report warns that even with the 2°C maximum temperature rise for climate change agreed by governments, this will not prevent serious and dramatic impacts on the world's ocean systems. In their outlook, four key messages emerge:

The ocean has a strong influence on the climate system and provides important services for humans.

The impacts on marine organisms and ecosystems have already been detected, and several will encounter a high risk of impact before the end of the century – even under the low emissions scenario, with these impacts occurring at all latitudes.

Substantial reductions of CO2 emissions are necessary immediately to prevent massive and possibly irreversible impacts on ocean ecosystems.

As atmospheric CO2 increases, the protection, adaptation and repair options for the ocean become less effective.

Jean-Pierre Gattuso, the report's principal author said, 'the ocean has been minimally considered at previous climate negotiations. Our study provides compelling arguments for a radical change at the UN conference on climate change'.

Dr David Lambert from FGS commented 'the potential for long-term damage to our oceans by continuing high levels of man-made CO2 production, is another crucial reason to ensure that developers of infrastructure involving the marine environment should do everything possible to mitigate damage to natural coastal habitats to help the survival of vulnerable species'.

The scientists warn that since 1750 the ocean has absorbed 30% of the carbon dioxide we have produced and, as CO2 is a mildly acidic gas, it is contributing to seawater acidity. But, because the ocean has buffered climate change by absorbing 90% of the additional heat created by our industrialised society since 1970, the extra heat makes it more difficult for the ocean to hold oxygen.