Ocean acidification
The oceans are absorbing high levels of carbon dioxide
(CO2) that have been mainly produced by human
activities, such as the burning of fossil fuels. When absorbed
CO2 dissolves in seawater it forms weak carbonic acid
and, as more CO2 is taken up by the ocean’s surface, the
pH of seawater decreases. Ocean acidity has already risen by about
30% since the start of the Industrial Revolution.
Ocean acidification is estimated to be currently occurring at a
rate faster than has been experienced during the last 20 million
years. If CO2 emissions continue to rise and the acidity
of the world’s oceans continue to increase at this rate, there may
be serious consequences for important marine cycles and processes
as well as for marine life. Such impacts are expected to reach far
beyond that of the marine environment and will have an influence
upon the health and wellbeing of human society.
Ocean acidification is a relatively recently recognised
phenomenon and PML has been at the forefront of this developing
research area, earning an internationally recognised reputation for
research and advice to policy makers. There is still a need for
more knowledge about how ocean acidification will impact upon the
oceans environmentally, socially and economically, and PML is
leading part of the UK Ocean Acidification Research Programme to
investigate the impacts of ocean acidification, including
co-ordinating how the knowledge gained will be made available to
stakeholders, policy makers, scientists and the public.
Projects
- Mediterranean Sea Acidification in
a changing climate (MedSeA)
Increases of atmospheric CO2 and associated decreases in
seawater pH and carbonate ion concentration this century and beyond
are likely to have wide impacts on marine ecosystems including
those of the Mediterranean Sea. Consequences of this process, ocean
acidification, threaten the health of the Mediterranean, adding to
other anthropogenic pressures, including those from climate change.
Yet in comparison to other areas of the world ocean, there has been
no concerted effort to study Mediterranean acidification, which is
fundamental to the social and economic conditions of more than 130
million people living along its coastlines and another 175 million
who visit the region each year. The MedSeA project addresses
ecologic and economic impacts from the combined influences of
anthropogenic acidification and warming.
- UK Ocean Acidification
Research Programme (UKOA)
The 5 year UK Ocean Acidification Research Programme is the UK’s
response to growing concerns over ocean acidification. The
programme will collaborate with other ocean acidification
programmes from around the world and aims to; reduce uncertainties
in predictions of carbonate chemistry changes and their effects on
marine biogeochemistry, ecosystems and other components of the
Earth System; understand the responses to ocean acidification, and
other climate change related stressors, by marine organisms,
biodiversity and ecosystems and to improve understanding of their
resistance or susceptibility to acidification; and provide data and
effective advice to policy makers and managers of marine
bioresources on the potential size and timescale of risks, to allow
for development of appropriate mitigation and adaptation
strategies.
- European Project on OCean Acidification
(EPOCA)
The goal of the EPOCA project is to advance our understanding of
the biological, ecological, biogeochemical, and societal
implications of ocean acidification. EPOCA aims to
document the changes in ocean chemistry and biogeography across
space and time and to determine the sensitivity of marine
organisms, communities and ecosystems to ocean acidification.
- Polar
research
The polar regions are particularly vulnerable to ocean
acidification as CO2 is more easily absorbed by waters
at colder temperatures. The Arctic, in particular, has been
identified as an area that will undergo the most dramatic change
due to the combined effects of global warming and ocean
acidification. PML has been involved in giant experiments in the
Arctic, where nine mesocosms, like enormous test tubes, have been
set up to study the impacts of ocean acidification on marine
organisms, ecosystems and climate.