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For those readers who wonder why we do not have even more carbon dioxide in the atmosphere than there is (See that endless line of cars up ahead?), I think I have a good part of your answer. Here, I present you with a little puzzle, in four easy to figure out. The last piece in that puzzle, however, is not among the three given below, but I will tell you its name: ATMOSPHERIC COLLAPSE.

The Royal Society
Ocean acidification due to increasing atmospheric carbon dioxide

30 Jun 2005
Ref: 12/05

Carbon dioxide (CO2) emitted to the atmosphere by human activities is being absorbed by the oceans, making them more acidic (lowering the pH the measure of acidity).

Evidence indicates that emissions of carbon dioxide from human activities over the past 200 years have already led to a reduction in the average pH of surface seawater of 0.1 units and could fall by 0.5 units by the year 2100. This pH is probably lower than has been experienced for hundreds of millennia and, critically, at a rate of change probably 100 times greater than at any time over this period.

The report outlines our best understanding of the impacts of these chemical changes on the oceans. The impacts will be greater for some regions and ecosystems, and will be most severe for coral reefs and the Southern Ocean. The impacts of ocean acidification on other marine organisms and ecosystems are much less certain. We recommend a major international research effort be launched into this relatively new area of research.

We recommend that action needs to be taken now to reduce global emissions of CO2 from human activities to the atmosphere to avoid the risk of irreversible damage from ocean acidification.

Department of Geological Sciences at San Diego State University
LAKE NYOS (1986)

"I could not speak. I became unconscious. I could not open my mouth because then I smelled something terrible . . . I heard my daughter snoring in a terrible way, very abnormal . . . When crossing to my daughter's bed . . . I collapsed and fell. I was there till nine o'clock in the (Friday) morning . . . until a friend of mine came and knocked at my door . . . I was surprised to see that my trousers were red, had some stains like honey. I saw some . . . starchy mess on my body. My arms had some wounds . . . I didn't really know how I got these wounds . . .I opened the door . . . I wanted to speak, my breath would not come out . . . My daughter was already dead . . . I went into my daughter's bed, thinking that she was still sleeping. I slept till it was 4:30 p.m. in the afternoon . . . on Friday. (Then) I managed to go over to my neighbors' houses. They were all dead . . . I decided to leave . . . . (because) most of my family was in Wum . . . I got my motorcycle . . . A friend whose father had died left with me (for) Wum . . . As I rode . . . through Nyos I didn't see any sign of any living thing . . . (When I got to Wum), I was unable to walk, even to talk . . . my body was completely weak." -- From A. Scarth (1999)


After investigating the site of the disaster, scientists were divided into two camps on the mechanism of rapid CO2 expulsion: (1) CO2 could have burst through the lake as the result of a sudden gas eruption, or (2) CO2 could have accumulated slowly in the lower part of the lake, only to be released abruptly by the overturning of the bottom waters by some unknown mechanism.

It had been known for years that the water in Lake Nyos was extremely enriched in dissolved CO2. The lake overlies a volcanic source, which appears to release CO2 and other gases. However, most of this gas does not escape into the atmosphere, but rather dissolves into the bottom waters of the lake. At a depth of over 200 meter, the sheer weight of the upper lake levels exerts considerable pressures on the bottom waters. This confining pressure allows CO2 to dissolve into the bottom waters without escaping to the surface, in much the same way that the cap on a carbonated beverage prevents CO2 from bubbling out of its container. At a depth of 200 meters, water can hold 15 times its own volume in CO2. It has been estimated that every liter of water in the lower part of the lake may have contained between 1 to 5 liters of CO2!

On August 15, 1984, a similar CO2 "eruption" occurred thirty kilometers away in Lake Monoun, killing 34 people. Investigators from the U.S. concluded that this event was from the CO2-rich bottom waters being overturned by a landslide, an earthquake, or abnormally heavy rains. American investigators were convinced that the same thing happened at Lake Nyos two years later. However, many European scientists were just as convinced that the Lake Nyos tragedy was the direct result of a gas-rich volcanic eruption. Most experts now favor the idea that the gas was released when the lower layers of the lake were somehow brought up to the surface.

There is little or no evidence that a landslide or an earthquake initiated the event. Instead, many scientists believe that the rapid accumulation of rainwater in the lake was responsible for overturning the bottom waters. The rainwater may have been blown to one side of the lake by strong August winds. Being denser than the warmer lake water, the rainwater mass would have descended down one side of the lake, thus displacing the bottom waters. This convective overturn resulted in the ascent and decompression of the bottom water, thus causing the dissolved gas to come out of solution (exsolve) and bubble upward at dramatic speeds. The bubbles themselves may have lowered the overall density of the gas-water mixture resulting in even greater rates of ascent, decompression, and exsolution. The result was a rapid and violent EXPULSION of CO2. So much gas escaped from this single event, that the surface level of Lake Nyos dropped by an entire meter.

September 19, 2006 @ 11:08AM - posted by John Timmer
Carbon dioxide lakes in the deep ocean

I often note that the universe is a very strange place, but our own planet has no shortage of unexpected discoveries. Decades ago, the mere existence of underwater hot vents and the strange communities of organisms they support were mind boggling. Now, unless the vents are accompanied by some weird life form like blind, furry lobsters, they don't make the news. A recent Japanese expedition to the subduction zone in the Okinawa Trough, however, zeroed in on something very new and unexpected by noting the absence of vent life in the area.

A movie of the exploration that accompanies the paper describing it lays out the narrative nicely. After surveying the vents in the area and the typical collection of life forms in the associated with them, the researchers noted an apparently lifeless zone nearby, with an unusual white surface. Attempts to get a sediment core from the area broke through the white material, allowing a geyser of buoyant liquid to erupt. What in the world is going on here?

It helps to remember that volcanic activity produces copious amounts of carbon dioxide. Two unusual things happen to CO2 at these depths. In contrast to surface conditions, where CO2 exists in gaseous or solid forms, it forms a liquid at the pressures present there, and that liquid is less dense than water. The second unusual thing is that it can form a solid (called a hydrate) by complexing with water molecules. The samples that came back suggested that the core had punctured a layer of CO2-hydrates, and went directly through a shallow lake of liquid CO2 and into a mixed CO2 sediment below.

Liquid CO2, in contrast to water, is non-polar, and will acidify any water it comes in contact with, which nicely explains the apparently lifeless zone in the area. But the authors checked the sediment that came back for bacteria and found that they could indeed adapt to these harsh conditions. A survey of DNA from archeabacteria (noted for living in extreme environments) found many familiar groups, but the authors suggest that the combination of groups present may be distinct from other known extreme communities. They also examined the chemistry of the carbon compounds present, which revealed the presence of some lipids that are normally formed only under aerobic conditions and by a type of bacteria not seen in the DNA survey. This, they suggest, indicates that there may be a type of bacteria new to science waiting to be identified in these lakes.

Elaine Meinel Supkis

Yes, I have written about the Nyos lake event in the past: people who want to mine the deep ocean are really putting all of us at severe risk.

Worse, there are nuts who want to take all this CO2 we are producing and then park it....UNDER WATER.

Since the seventies, this has been under discussion.

The shocking new studies of the Permian Extinction should be a very stark warning to all of us.

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