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  • From: Lawrence London <lfljvenaura@gmail.com>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: [permaculture] BBC News - 'Jacuzzi vents' model CO2 future
  • Date: Sun, 19 Feb 2012 11:07:30 -0500

http://www.bbc.co.uk/news/science-environment-17088154

19 February 2012 Last updated at 09:53 ET

'Jacuzzi vents' model CO2 future

By Jonathan Amos Science correspondent, BBC News, Vancouver
At these volcanic vent sites, carbon dioxide bubbles up like a Jacuzzi
Continue reading the main story

An acid test for policy
Acid oceans turn 'Nemo' fish deaf
Fish 'at risk' in acidified ocean

A UK scientist studying volcanic vents in the ocean says they hold a
grave warning for future marine ecosystems.

These vents have naturally acidified waters that hint at how our seas
might change if atmospheric carbon dioxide levels continue to rise.

They are conditions that would make it harder for corals and similar
organisms to make the hard parts in their bodies.

Dr Jason Hall-Spencer's work suggests our oceans could lose perhaps
30% of their biodiversity this century.

The Plymouth University researcher has been presenting his latest
findings to a major conference in Vancouver, Canada.

"I am investigating underwater volcanoes where carbon dioxide bubbles
up like a Jacuzzi, acidifying large areas of the seabed, and we can
see at these vents which types of organisms are able to thrive and
which ones are most vulnerable," he told the annual meeting of the
American Association for the Advancement of Science (AAAS).

Dr Hall-Spencer treats the vents like a time machine. As he swims
towards them, the pH level of the water falls and he can use
particular locations to simulate what the open ocean will be like in
the decades ahead if emissions of atmospheric CO2 go unchecked and
much of the that gas is absorbed into sea.

"What we see as you swim along a gradient of carbon dioxide, up to
levels we expect for the end of this century, is diversity loss.

"As you go along that gradient, species drop out of the system," he
told BBC News.

"It's not all calcified species - ones with hard shells or skeletons -
which drop out; there are other organisms with soft bodies which drop
out as well.

"This CO2 is a stressor. Some organisms can adapt but there're only a
few species that can handle it. If I extend the gradient up to the
year 2100 - that represents a 30% loss in biodiversity."

Continue reading the main story

ACIDIFYING OCEANS

The oceans are thought to have absorbed up to half of the extra CO2
put into the atmosphere in the industrial age
This has lowered their pH by 0.1
pH is the measure of acidity and alkalinity
It ranges from pH 0 (very acidic) to pH 14 (very alkaline); 7 is neutral
Seawater is mildly alkaline with a "natural" pH of about 8.2
The IPCC forecasts that ocean pH will fall by "between 0.14 and 0.35
units over the 21st Century, adding to the present decrease of 0.1
units since pre-industrial times"

At the end of last year, Dr Hall-Spencer published his findings on one
volcanic vent site off Ischia Island near Vesuvius. But at this
meeting, he reported soon-to-be-published data gathered at other
volcanic vents in Europe, Baja California and Papua New Guinea. They
all show the same outcomes as at Ischia.

"What's strange is that we see some organisms really up-regulate their
physiology to try to cope with conditions - they grow faster. But it's
like us panting for oxygen at high altitude - they're struggling.

"And in the summer, when temperatures are high, these organisms that
are struggling just die. And that's very problematic because of course
carbon dioxide not only acidifies seawater, but it is increasing the
temperature of the atmosphere. And those two things combined are a
double whammy."

Shells, like this Hexaplex trunculus, dissolve at CO2 levels predicted
for later this century

The world's oceans have already absorbed a third to a half of the CO2
produced by humans, principally by the burning of fossil fuels, over
the past 200 years.

This has resulted in a reduction of the pH of seawater by 0.1 units on
the 14-point scale. If emissions of CO2 continue to rise as forecast,
there could be another drop in pH up to perhaps 0.4 units by 2100.

These are changes that are occurring far too fast for the oceans to
correct naturally, said Dr Richard Feely with the US National Oceanic
and Atmospheric Administration (Noaa)

"Fifty-five million years ago when we had an event like this (and that
took over 10,000 years to occur), it took the oceans over 125,000
years to recover, just to get the chemistry back to normal," he told
BBC News.

"It took two to 10 million years for the organisms to re-evolve, to
get back into a normal situation.

"So what we do over the next 100 years or 200 years can have
implications for ocean ecosystems from tens of thousands to millions
of years. That's the implication of what we're doing to the oceans
right now."

Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter

More on This Story

Related Stories

An acid test for policy 23 JANUARY 2012, SCIENCE & ENVIRONMENT
Acid oceans turn 'Nemo' fish deaf 31 MAY 2011, SCIENCE & ENVIRONMENT
Fish 'at risk' in acidified ocean 21 NOVEMBER 2009, SCI/TECH
Bubbling sea signals coral threat 29 MAY 2011, SCIENCE & ENVIRONMENT
Coral reefs heading into crisis 23 FEBRUARY 2011, SCIENCE & ENVIRONMENT

Related Internet links



  • [permaculture] BBC News - 'Jacuzzi vents' model CO2 future, Lawrence London, 02/19/2012

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