http://www.climateoutcome.kiwi.nz/blog.html

Acidification of Oceans.

25/4/2015

Is this our biggest threat?
The big action in climate change is in the oceans and largely un-noticed by us. Half of the oxygen we breathe comes from phytoplankton and these tiny creatures are under threat. As CO2 in the atmosphere has increased by 40%, from 280 ppm to 400 ppm, much of it is absorbed by the ocean and this has made the sea water 30% more acidic. Phytoplankton have a calcium carbonate structure which is very susceptible to a more acidic environment and is affecting their reproduction.

Satellite’s measuring calcium carbonate in the oceans and research by the University of Colorado Boulder show that there is a big reduction in most oceans over the last 17 years. The Southern ocean is showing the biggest loss with 24% and there is a 9% reduction in the Indian and Pacific regions of the Southern ocean.

This big increase in Ocean acidity is affecting other creatures with calcium carbonate structures such as coral, crayfish, mussels and oysters. these creatures, together with plankton and zooplankton form the base of the marine food chain and if they disappear all marine aquatic life will suffer.
Humans get 25% of their food from the sea and the oceans are fundamently important to our whole existence.

6 Comments

Bob Bristow

30/4/2015 11:05:39 am

Living in the Southern Hemisphere (where warming is progressing slower that the Northern Hemisphere, especially Arctic high latitudes) I have been fascinated how the 2 halves keep in synchronization.

I was interested in a recent finding (over 70 authors), it was found that abrupt warming from the North Atlantic took around 200 years to reach the Antarctic via Ocean Currents. Seems we will have a little longer to adapt way down in the Southern Hemisphere (good for 2 or 3 generations) Amazing research project: -

http://www.realclimate.org/index.php/archives/2015/04/how-long-does-it-take-antarctica/

http://phys.org/news/2015-04-northsouth-climate-year-lag-events.html

Bob Bingham

1/5/2015 02:47:34 pm

Hello Bob. What I am trying to find out is how long it takes for water that sinks in the Arctic to resurface in the Southern oceam. So far estimates range between 1000 years and 30. Any ideas?

Bob Bristow

3/5/2015 10:25:15 am

Hi,

Flattered that you request my ideas, Prof David Archer (I'm a big fan) stated that it takes around 1000 years for a complete circumnavigation and overturn cycle in currents around the globe, this article in RealClimate suggests that a North Atlantic signal propagates to the South Atlantic region in around 30 years then it takes couple of centuries to reach the Antarctic Circumpolar Current (ACC), so 200 years seems a reasonable estimate to me.

"The ocean itself can propagate signals very fast, via adjustment of the upper ocean by fast Kelvin waves propagating along the ocean boundaries (e.g. Johnson and Marshall, 2002). For example, Schmittner et al. (2003), and Rind et al. (2001) both found that the North Atlantic signal in their models propagates to the South Atlantic region very quickly, appearing in subsurface waters with a time lag of only about a few decades. However, they also find a century or multi-century delay in the further southward propagation from the South Atlantic to the Antarctic across the Antarctic Circumpolar Current (ACC)."

regards Bob

Bob Bristow

3/5/2015 02:35:45 pm

Bob,

You really set me off thinking on the Ocean current travel time question, the problem is Earth Science is so complex it is difficult to find a neat tabular answer, my favourite guru (Prof David Archer) in a lecture states 1000 year for complete traverse of the planet, which NOAA also agrees with. National Geographic puts it at 500 years. I think that 200 years is not a bad estimate (Arctic to Antarctic) . based on the RealClimate article and computer modelling.

Earth Science is incredibly complex, I hope and pray that NASA's ES budget is not cut drastically as the Republicans are pushing for right now. The only saving grace is that other agencies (like the ESA) are also covering Earth Science from space.

However the global warming science of radiative blocking properties of GHG's is very established, straightforward and simple (vibrating molecules), as is NASA, NOAA and JMA global temperatures monthly releases and the NOAA/Scripps monthly CO2 atmospheric releases.

The variability of Earth's climate confuses it all and gives deniers the chance to confuse, but the fact is we have supercharged the atmosphere and the effects are now biting.,

Keep up the good work, it is truly appreciated ..

Bob Bingham

5/5/2015 01:40:38 am

Hello Bob. Thanks for the leads on ocean circulation. The summary is 1000 years for complete overturning of the oceans, 200 years for a climate effect from North to South and a possible 30 years for Arctic Gulf stream water to reach the Southern ocean, This is all quite reasonable but we dont really know much about the deep oceans and the thermohaline circulation maps always show a distinct clod current flowing from Norway to the Southern Ocean.and then round the world.
The Gulf stream surface water can flow at 5 MPH at 8 Klph and if the total distance of the current from Norway to round the Southern ocean is 15,000 Kl and there are 8760 hours in a year then even at 1 Kl per hour it would take 6 months.
I don't doubt the thirty years but I would like to see how the figure was arrived at. Bob

Bob Bingham

5/5/2015 05:44:40 am

Hello again Bob. Re_reading my email it looks as though I expect the Gulf stream water to reach the Southern ocean in six months which I don't. It's just that I suspect that a lot of Northern hemisphere CO2 is sucked into the Gulf stream and delivered to us here in the South and I want to see some research that deals with the flow and distribution of water in the deep oceans.

Bob Bingham Blog page.

Acidification of Oceans.

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