By Nina Chestney
LONDON, March 21 (Reuters) – The cost of damage to the
world’s oceans from climate change could reach $2 trillion a
year by 2100 if measures to cut greenhouse gas emissions are not
stepped up, a study by marine experts said on Wednesday.
The study found that without action to limit rising
greenhouse gas emissions, the global average temperature could
rise by 4 degrees Celsius by the end of the century causing
ocean acidification, sea level rise, marine pollution, species
migration and more intense tropical cyclones. It would also
threaten coral reefs, disrupt fisheries and deplete fish stocks.
In the study, “Valuing the Ocean”, marine experts led by the
Stockholm Environment Institute (SEI) analysed the most severe
threats facing the world’s marine environment and estimated the
cost of damage from global warming.
It found nitrogen-rich fertilisers and waste would strip
more ocean areas of oxygen, causing what is known as hypoxic
dead zones, which are already found in more than 500 locations.
“By 2100, the cost of damage if we do not radically cut
emissions rises to $1.98 trillion, or 0.37 percent of global
gross domestic product,” the SEI said.
The loss of tourism would incur the highest cost at $639
billion per year. The loss of the ocean carbon sink, the seas’
ability to soak up carbon dioxide (CO2), would cost almost $458
billion, the study showed. Warmer water holds less CO2.
If cuts in emissions of planet-warming greenhouse gases were
carried out more urgently and temperature increases were limited
to 2.2 degrees C, nearly $1.4 trillion of the total cost could
be avoided, the study found.
However, such progress would require the widespread use of
radical carbon removal technologies like sucking carbon dioxide
out of the atmosphere, Frank Ackerman, one of the report’s
authors told Reuters.
“The faster we stop emissions rising, the lower the damage
will be. But on current technology, I wouldn’t be surprised if
we end up on a 4 degree C pathway,” said Ackerman, senior
economist and director of the Climate Economics Group at SEI’s
The study did not put a monetary value on the loss of some
species which inhabit the world’s oceans, critical processes
like nutrient cycling or the loss of coastal communities’
traditional ways of life.
“The challenge is to figure out what parts of the ocean
environment have a value you can put a meaningful price on.
There are very important areas which we still can’t incorporate
into a market,” Ackerman said.
The study also recommended that the United Nations appoints
a High Commissioner for Oceans to coordinate research and
action, that ocean services should be more integrated into
economic policy and that there should be more preparation for a
1-2 metre sea level rise by the end of the century.
A new potential market in “blue carbon” could also present
an important economic opportunity, SEI said.
Marine ecosystems, like mangroves and sea grasses, contain
far more carbon than terrestrial forests but are being degraded
at a more alarming rate and are not yet included in carbon
offset schemes, which reward investors in emissions reduction
projects in developing countries with carbon credits.
“There are many questions about the legal responsibility for
different parts of the ocean. Tracking terrestrial carbon
offsets is enough of a challenge, tracking the marine ones is
going to be a new challenge,” Ackerman said.
“But they need to be included. Leaving out an area like that
could undermine progress being made in areas that are being
taken care of.”
(Editing by Janet Lawrence)
Article source: http://www.vision.org/visionmedia/article.aspx?id=53945