News release
Public release date: 21-May-2008
European Science Foundation
Ocean acidification — another undesired side effect of fossil fuel-burning
Up to now, the oceans have buffered climate
change considerably by absorbing almost one third
of the worldwide emitted carbon dioxide. The
oceans represent a significant carbon sink, but
the uptake of excess CO2 stemming from man’s
burning of fossil fuels comes at a high cost:
ocean acidification.
Research on ocean acidification is a newly
emerging field and was one of the major topics at
this year’s European Geosciences Union (EGU)
General Assembly held in Vienna in April. The
European Science Foundation EUROCORES (European
Collaborative Research) programme EuroCLIMATE,
which addresses in particular global carbon cycle
dynamics, organized and co-sponsored several
sessions on ocean acidification.
The chemistry is very straight-forward: ocean
acidification is linearly related to the amount
of CO2 we produce. CO2 dissolves in the ocean,
reacts with seawater and decreases the pH. Since
the industrial revolution, the oceans have become
30 percent more acidic (from 8.2 pH to 8.1 pH).
“Under a “business as usual scenario, predictions
for the end of the century are that we will lower
the surface ocean pH by 0.4 pH units, which means
that the surface oceans will become 150 percent
more acidic – and this is a ‘hell of a lot’ “,
said Jelle Bijma, chair of the EuroCLIMATE
programme Scientific Committee and a
biogeochemist at the Alfred-Wegener-Institute
Bremerhaven. “Ocean acidification is more rapid
than ever in the history of the earth and if you
look at the pCO2 (partial pressure of carbon
dioxide) levels we have reached now, you have to
go back 35 million years in time to find the
equivalents” continued Bijma. A maximum allowed
change in pH, where the system is still
controllable, needs to be found. This is a major
challenge considering the multifaceted unknowns
that still are to be clarified. This so-called
“tipping point” is currently estimated to allow a
drop of about 0.2 pH units, a value that could be
reached in as near as 30 years. More research and
further modeling needs to be undertaken to verify
the predictions.
The expected biological impact of ocean
acidification remains still uncertain. Most
calcifying organisms such as corals, mussels,
algae and plankton investigated so far, respond
negatively to the more acidic ocean waters.
Because of the increased acidity, less carbonate
ions are available, which means the calcification
rates of the organisms are decreasing and thus
their shells and skeletons thinning. However, a
recent study suggested that a specific form of
single-celled algae called coccolithophores
actually gets stimulated by elevated pCO2 levels
in the oceans, creating even bigger uncertainties
when it comes to the biological response. “There
are thousands of calcifying organisms on earth
and we have investigated only six to ten of them,
we need to have a much better understanding of
the physiological mechanisms” demanded
Jean-Pierre Gattuso, a speaker from Laboratoire
d’Océanographie Villefranche invited by
EuroCLIMATE. In addition, higher marine life
forms are likely to be affected by the rapidly
acidifying oceans and entire food webs might be
changing.
So far, hardly any economic impact assessments of
ocean acidification exist, but with the fragile
marine ecosystems under threat, it can be assumed
that fisheries and many coastal economies will be
severely affected. Many of these societies depend
on the sea as their main source of food and the
loss of species is highly detrimental to them;
coral reefs serve as highly valuable tourist
destinations and as natural protections against
natural hazards such as tsunamis. Together with
climate change, ocean acidification poses a major
challenge to the oceans as a human habitat.
“Ocean acidification is happening today and it’s
happening on top of global warming, so we are in
double trouble” stated Bijma. Only a serious cut
of CO2 emission can reduce ocean acidification.
Therefore, knowledge on ocean acidification is
being disseminated and awareness among
policymakers and the general public raised. “We
need to make sure that the message gets delivered
to the right people at the right time” urged
Carol Turley, lead author of the Nobel
prize-winning IPCC report and scientist at the
Plymouth Marine Laboratory. According to her, a
concise integrated opinion of leading scientists
is necessary, and it would be useful for policy
makers to devote one integrated chapter on the
impacts of climate change including ocean
acidification on the marine environment in a
future IPCC report.
European science has taken the initiative to act
and gain more urgently needed insight on this
phenomenon of global change; an EU project on
ocean acidification will be launched next month.
The European Geosciences Union (EGU), an
influential interdisciplinary organization, is
also being proactive: “EGU is in the process of
putting together a position statement on ocean
acidification” said Gerald Ganssen, President of
the EGU. As a result attained at a strategic
workshop held in January, the ESF is currently
producing a ‘Science Policy Briefing’ which is to
be targeted at the major stakeholders and actors
in the field. In addition it was felt that the
issue of ocean acidification needs to be
addressed in a pan-European effort and that more
intensive European collaboration is required,
which could be achieved through one of the ESF
Science Synergy tools such as EUROCORES.
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Notes to the editors:
The aim of the European Collaborative Research
(EUROCORES) Scheme is to enable researchers in
different European countries to develop
collaboration and scientific synergy in areas
where European scale and scope are required to
reach the critical mass necessary for top class
science in a global context. The scheme provides
a flexible framework which allows national basic
research funding and performing organisations to
join forces to support excellent European
research in and across all scientific areas. The
European Science Foundation (ESF) provides
scientific coordination and support for
networking activities of funded scientists
currently through the EC FP6 Programme, under
contract no. ERAS-CT-2003-980409. Research
funding is provided by participating national
organisations.
The climate for the next century, and thereafter,
is expected to be largely different from the
present and the recent past. CO2 concentration is
expected to reach levels unequalled over the past
millions of years. Temperature is also rising
rapidly. The last 150 years of meteorological
observations and the reconstruction over the last
millennium display a quite uniform climate. Only
the reconstruction of paleoclimates extending
much further back in time can help build a
database with a broader climatic diversity. Such
a database will, in addition, offer the
possibility to test the reliability and
robustness of the models used for future climate
scenarios and thus to better understand how the
climate system works. EuroCLIMATE focuses both on
reconstructing past climates using different
well-dated and calibrated proxy records and on
modelling climate and climate variations for a
better understanding of the underlying physical,
chemical and biological processes involved.
The European Science Foundation (ESF) provides a
platform for its Member Organisations to advance
European research and explore new directions for
research at the European level. Established in
1974 as an independent non-governmental
organisation, the ESF currently serves 77 Member
Organisations across 30 countries.
For further information on EuroCLIMATE, please go to www.esf.org/euroclimate
For further information on the EUROCORES Scheme,
please go to www.esf.org/eurocores
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