Geoscience Reference
In-Depth Information
5
Ocean Acidification
and its Consequences
5.1. Introduction
Before the Industrial Revolution, the flow of carbon from the
ocean into the atmosphere was slightly higher than that from the
atmosphere into the ocean (70.6 and 70 Gt C per year, respectively
[IPP 07]). Industrialization, along with an increased use of fossil fuels,
production of cement and land-use changes, have led to an additional
flow of carbon of anthropic origin into the atmosphere. The average
growth of emissions was 2% per year during the decade 1980-1990
and 3.1% per year since 2000 [PET 12]. It was 5.4% in 2010, a year
during which the total of all emissions amounted to 10 Gt C [PET 12].
The concentration in carbon dioxide (CO
2
) in the atmosphere has,
therefore, increased from 280 parts per million by volume (ppmv) in
1750 to 394 ppmv in 2012.
The CO
2
dissolved in the surface of most of the world's oceans is
in near equilibrium with the atmospheric CO
2
. The increase in the rate
of CO
2
in the atmosphere, therefore, results in an increase in the flow
of carbon into the oceans and a reversal of the pre-industrial trend; the
ocean has become a CO
2
sink with a net uptake of about 2 Gt C
per year
[IPP 07].
