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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.

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Is CO2 killing our rivers?

19/4/2015

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We tend to take the natural composition of rainfall that fills our rivers and streams as a constant but, like a lot of things today, that is no longer the case.

A healthy stream should be slightly alkaline and have a pH level in a range of between 7.2 and 8.0 (7 is neutral) but water that falls as rain has washed CO2 out of the atmosphere and is slightly acidic at 5.7. This acidic rainwater is made more alkaline and moved to 7.2+ by washing minerals out of the rocks and soil and the addition of organic matter from trees and grasses.

Organisms living in the streams are comfortable in alkaline water at pH levels above 7.2 and at that level will thrive. The smaller invertebrate of mayfly, caddisfly larvae and stonefly are the key here as they form the base of the fresh water fish food chain and also are sensitive to water quality. They could be called the canary in the coal mine, if the canary dies the miner is likely to die as well.

The current level of CO2 in the atmosphere has just reached 400 ppm compared to its natural high of 280 ppm, 150 years ago before we started burning coal. This has raised the acidity of fresh water from the atmosphere by 33%.
Rivers and streams are hugely variable but never the less this big change in acidity must be affecting the natural habitat of our freshwater aquatic life in much the same way that ocean acidity is affecting our mussels and corals and anything else with a calcium carbonate shell like plankton.

This chart from NOAA illustrates how not all fresh water aquatic life can survive a change to more acidic water and as with the oceans if the smallest creatures can not survive the base of the food chain is cut off.

The big increase in the amount of nitrogen from cattle effluent is well recognised for the damage it does, but acidity increases from atmospheric CO2 are not so well reported and yet need just as much attention.
It highlights the necessity of looking after the streams we have and treating a health stream as a resource to combat increasing spells of drought caused by a warming world.

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Disappearing glaciers.

18/4/2015

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I have just visited the Franz Joseph glacier for the first time and was shocked to see how small the remnants are. An Australian lady on the walk with me said that she had walked on the glacier when she was here thirty years ago and was amazed how far it had retreated. The glacier used to fill the whole valley in 1865.
Climate change is simple. More CO2 in the atmosphere, the temperature goes up, the ice melts. It’s the speed at which it is happening that is the problem.

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Gulf Stream slowing and Sea level rise.

9/4/2015

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The value of monitoring the oceans has become apparent in a report in Nature by Quirin Schiermeier.
He has shown that since the deployment of the RAPID monitoring array which is string of moored buoys across the Atlantic there has been a two thirds reduction in the speed of the Gulf Stream current.

A separate report from Florida shows that for the last five years the sea level has been rising at 1.27’ a year or 160 mm.

This is similar to the NOAA report which showed a similar sea level rise in the Northeast of the USA between 2009 and 2010.

In the past sea levels in the oceans have risen 120 meters due to an 8C increase in temperature over 15,000 years or so. This rise was mainly due to melting ice but also partly due to expansion of the sea caused by the increased temperature. On a global scale today we know that the contribution of these two factors has produced a sea level rise of 3.2 mm a year caused by a steady increase in the volume of water and the contribution from Greenland and Antarctica is growing.

However there are other factors involved that can change the level of the sea locally. A steady trade wind can cause water to pile up on the downwind shore, the gravitational pull of the mass of ice in Greenland can pull extra water to its shores and also ocean currents and tides can cause water to pile up or sink away.

As the current of the Gulf Stream leaves the coast of the USA and heads towards Europe it sucks water from the shore of the USA and if that current declines in speed then this water will not be pulled so hard and will return to the shore causing a rise in sea level.

There is no overall increase in the quantity of water but these local changes can flood houses and towns that were previously dry.

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Sea level rise may not be all of Florida’s problems.

9/4/2015

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Florida has so many problems related to climate change it is hardly surprising the Governor is denying that anything is happening. I think that we are all fairly well aware that with a one metre rise in sea level massive amounts of Florida’s coast and infrastructure will be permanently flooded.

These little spots of blue are where, with a one metre sea level rise, salt water has percolated into the land.

If anyone thinks that the solution is to erect a sea wall to keep the salt water out they need to look at the limestone rock that Florida sits on.
This is what the calcium rock that Florida is made of looks like. Water can flow through it easily.

Florida is all about water and with 60” ( 1.5 metres) a year there is a lot of fresh water.
This illustration shows how fresh water from rain fills voids in the rock to form a lens to keep the salt water at bay.

This illustration shows how rainwater percolates into the porous rock and forms a lens of freshwater with some pressure to keep the salt water out. The second illustration shows how rising sea levels can overcome the freshwater making it salty and unsuitable for drinking, watering crops and will kill trees.

In the case of Florida I can see no reason why the rain should stop but there was no advance warning for the Californian droughts, except that they have had them before. And certainly no advance warning that the jet stream would stick and cause droughts in California and the South West and also heavy floods or snow in the Northeast and warm weather in Alaska.

All these graphs show the deep meandering jet stream and how they affect the weather in the regions. If the jet stream moved a little bit further to the East then a drought would ensue.

Florida has a fairly constant rainfall of fifty to sixty inches, with or without a hurricane but if it stopped and did not replenish the water lens then sea water would flood the underground water supplies and it would never be the same again.

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Bob Bingham Blog page.

Acidification of Oceans.

Is CO2 killing our rivers?

Disappearing glaciers.

Gulf Stream slowing and Sea level rise.

Sea level rise may not be all of Florida’s problems.

Bob Bingham

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