The world’s leading scientists in ocean acidification have released an open communiqué stating the issue is an urgent scientific and policy challenge.
The communiqué featured the deliberations of world experts at the ‘Ocean Acidification: Australian Impacts in the Global Context’ workshop sponsored by the Australian Department of Climate Change, held in June in Hobart by the Antarctic Climate & Ecosystems Cooperative Research Centre (ACE CRC).
Dr Will Howard from the ACE CRC and CSIRO’s Dr Bronte Tilbrook released the communiqué on 5 August 2008, on behalf of the top-callibre participants of the workshop.
Key points in the communiqué are that:
* the uptake of carbon dioxide emissions by the ocean is occurring at a rate exceeding the natural buffering capacity of the ocean.
* the current trajectory of carbon emissions will cause a change in ocean acidity, during this century, that is greater in extent than anything likely to have occurred for millions of years.
* Acidification due to ocean uptake of carbon dioxide is likely to have serious consequences for marine ecosystems and biodiversity in our region over this century.
“Ocean acidification is unique among human impacts on the marine environment in its pervasiveness and persistence” the document says, “requiring heightened awareness and dialogue among scientists, policymakers, and the public.”
The communiqué follows the release of the ACE CRC’s detailed Position Analysis on ocean acidification, released during the workshop.
The communiqué and the position analysis are available online.
ScienceAlert.com, 6 August 2008. Article.
some points in this position analysis can benefit from clarification:
1. The Southern Ocean does not (pg 6 col 1) “contain a disproportionate amount of the oceanic inventory of anthropogenic CO2 compared with other, warmer oceans.” The largest water-column inventory is in fact in the North Atlantic due to deep-water formation taking down anthro Co2, see Figure 1 of Sabine et al 2004:
http://www.sciencemag.org/cgi/reprint/305/5682/367.pdf
Even if considering only surface waters, the S Ocean still does not hold unusually large concentrations of anthrpogenic CO2 (see Fig 2 of the same paper)
2. It is not the case that (pg 6 col 3) “ocean acidification thus can be viewed as an impact ‘advancing from the south’.” The Southern Ocean does not have especially low pH. It has especially low CaCO3 saturation states, but then so too does the Arctic Ocean (this is tied to the effect of temperature on CO2 solubility). Cold waters naturally hold more dissolved inorganic carbon when in equilibrium with atmospheric CO2 and this tends to entail lower carbonate ion concentrations. Ocean acidification is lowering surface seawater pH pretty much everywhere, without advancing from any one place.
regards, Toby Tyrrell.