Wednesday, October 26, 2016

Yes, Ocean Life Is Headed To Extinction - Perhaps Even In Millennials' Life Time

Image may contain: plant, sky, outdoor, nature and water

Image may contain: ocean, sky, plant, outdoor, nature and water
Top: Healthy tropical coral reef supporting tabletop and staghorn corals. Bottom: A degraded tropical coral reef, affected by ocean acidification and higher ocean temperatures from global warming.

In a previous post (October 3rd) skewering the cockeyed global warming narrative of a putative high IQ member of Intertel, I noted how Janice and I had taken a tourist cruise sub across Carlisle Bay in Barbados e.g.
Image may contain: ocean, sky, outdoor, water and nature

This tour sub enabled us to see not only healthy coral reefs but also decimated ones, bleached out from higher water temperatures. These degraded reefs very much resembled those shown in the graphic above. It is now clear that this phenomenon is not localized by any means, but occurring worldwide, from the Caribbean to the Pacific to the Indian Ocean.

As recently as 2012 scientists from Columbia University, which led the research. have found surging levels of carbon dioxide in the atmosphere that forced down the pH of the ocean by overall 0.1 mean unit in the last century. This is 10 times faster than the closest historical comparison from 56 million years ago. It's deadly serious because - like the margins for ushering in a runaway greenhouse effect, the margins of safety for acidic oceans are extremely low. Hence, one can't tell by the small magnitude of numerical pH that the increment change is nothing to fret over.

As noted in earlier blogs: the seas absorb CO2 from the atmosphere, forming carbonic acid. The particular chemical reaction is:

H2O + CO2 -> H2 CO3

The lower the pH level of the seawater ('7' is neutral pH), the more acidic. This is also worrisome because mass extinctions of marine creatures in the past have been linked to instances of increased ocean acidification. Thus,  the current incremental change could also threaten important species. This according to Baerbel Hoenisch, the paleoceanographer at Columbia who was lead author of a  2012  paper that appeared in the journal Science. As he noted:

If industrial carbon emissions continue at the current pace, we may lose organisms we care about — coral reefs, oysters, salmon,”

Meanwhile, the UN’s Intergovernmental Panel on Climate Change has said ocean pH may fall another 0.3 units this century. Even before the dawning of the year 2100 that means the generation of millennials could behold an ocean devoid of accessible sea life, leaving only jellyfish.  Anyone think or believe we'd see surfing contests in such waters?

According to ocean research scientist Carles Pelejero, depending on how we humans respond - whether we take action or continue fouling our waters- the pH could reach a low of 7.7 by 2100.  (Note that while technically not in the "acid scale"  i.e. pH  less than 7, we are talking about the direction of the pH change, toward higher acidity.) For reference, Pelejro leads a section of the Institut di Ciencies del Mar but his specific field is marine paleo reconstruction. Some have called it "seabed archaeology - as it uses drills to take samples from deep in the sediment at the bottom of the oceans. Using such samples, marine scientists can assess how the geochemistry of sea creatures has altered.

One of the most horrific findings was associated with the     PETM or Palo-Eocene Thermal Maximum, 55 million years ago. Over a 100ky period the evidence of samples showed a massive die off of shell -based life. If projections hold the same will occur by the end of this century.

An associated worry is that a stable, solid form of methane (clathrates) may be disrupted by current ocean chemical changes in what is called the "clathrate gun hypothesis". Should disruption occur, by changes in the ocean water chemistry and higher temperatures, it would mean the release of a greenhouse gas vastly more damaging than CO2.

For comparison, in the PETM phase referenced above, - which conditions we may now be headed for again  -  sea levels were as much as 330 feet higher than they are today.  Such a rise in sea levels would be enough to obliterate Europe, Florida and the northeast U.S. as well as Argentina.

Pelejero, for his part, is most concerned about the rapidity of the changes taking place now. He has noted that the same shifts that happened over the course of a few thousand years during the PETM era are now due to happen over a few centuries. - counting from the onset of the Industrial Revolution. That means their culmination by the year 2100, barely 83 years away.

Already a number of precursor effects have been observed, including:

- Around the world the shells of some animals are thinner than they were 300 years ago.

- An acidification spike off the coast of British Columbia in February, 2014 wiped out 10 million scallops.

- Foraminfera, the tiniest shelled plankton in the ocean are having trouble growing as they did in the PETM era

Could the seas of the world be filled with only jellyfish within 50 to 100 years? There is every possibility, indeed probability, if we continue our deplorable ways, pumping out ever more CO2 and turning the oceans into a giant waste pit.

Will the climate deniers finally come to their senses when they or their families are no longer able to get fresh fish to eat?   One assumes with all the marine resources, food potential devastated they will finally see the folly of upholding a world view based on Neoliberal, capitalist economics. But I wouldn't put money on it!

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