oceans are an enormous store of carbon, substantially greater than
on land or in the atmosphere, and play a key role in the global
carbon cycle, especially in helping regulate the amount of
CO2 in the atmosphere.
The oceans are important because they have taken up 27-34% of
the CO2 produced by humankind through the burning of
fossil fuels, cement manufacturing and land use changes since the
Whilst this has somewhat limited the historical rise of
CO2 in the atmosphere, thereby reducing the extent of
greenhouse warming and climate change caused by human activities,
this has come at the price of a dramatic change to ocean chemistry.
In particular, and of great concern, is the measurable change in
ocean pH and carbonate and bicarbonate ion concentration - 'ocean
acidification'. Our understanding of the impact of CO2
on the carbonate chemistry is such that we know with very high
certainty that ocean acidification will continue.
Ocean acidification events in the Earth's past may help us
interpret the future of our oceans in a world of increasing
As a result of an ocean acidification event 55.5 million years
Increasing ocean acidification has the potential to harm marine
ecosystems and alter the oceans' ability to take up excess
CO2 from the atmosphere leading to a direct impact on
future climate change.
Socio-economic impacts of ocean acidification are difficult to
predict. However, the goods and services provided by the marine
environment to the UK are important; for example, multi-million
pound fisheries, fish meal and aquaculture industries employ tens
of thousands of people and if impacted by ocean acidification this
could have a direct economic effect. Globally, coral reefs have
been valued at $30 billion and provide food, tourism and shore
protection. Any threat to them will be important for the economies
of some of the UK's overseas territories.
PHOTOS from top: Donna Roberts, Donna