The greenhouse gas that saved the world
August 18, 2009When Planet Earth was just cooling down from its fiery creation, the sun was faint and young. So faint that it should not have been able to keep the oceans of earth from freezing. But fortunately for the creation of life, water was kept liquid on our young planet.
For years scientists have debated what could have kept earth warm enough to prevent the oceans from freezing solid. Now a team of researchers from Tokyo Institute of Technology and University of Copenhagen's department of chemistry have coaxed an explanation out of ancient rocks, as reported in this week's issue of PNAS.
A perfect greenhouse gas
"The young sun was approximately 30 percent weaker than it is now, and the only way to prevent earth from turning into a massive snowball was a healthy helping of greenhouse gas," Associate Professor Matthew S. Johnson of the Department of Chemistry at University of Copenhagen explains. And he has found the most likely candidate for an archean atmospheric blanket. Carbonyl Sulphide: A product of the sulphur disgorged during millennia of volcanic activity.
"Carbonyl Sulphide is and was the perfect greenhouse gas. Much better than Carbon Dioxide. We estimate that a blanket of Carbonyl Sulphate would have provided about 30 percent extra energy to the surface of the planet. And that would have compensated for what was lacking from the sun", says Professor Johnson.
Strange distribution
To discover what could have helped the faint young sun warm early earth, Professor Johnson and his colleagues in Tokyo examined the ratio of sulphur isotopes in ancient rocks. And what they saw was a strange signal; A mix of isotopes that couldn't very well have come from geological processes.
"There is really no process in the rocky mantle of earth that would explain this distribution of isotopes. You would need something happening in the atmosphere," says Johnson.
The question was: What.
Painstaking experimentation helped them find a likely atmospheric process. By irradiating sulphur dioxide with different wavelengths of sunlight, they observed that sunlight passing through Carbonyl Sulphide gave them the wavelengths that produced the weird isotope mix.
"Shielding by Carbonyl Sulphide is really a pretty obvious candidate once you think about it, but until we looked, everyone had missed it," says Professor Johnson, and he continues. "What we found is really an archaic analogue to the current ozone layer. A layer that protects us from ultraviolet radiation. But unlike ozone, Carbonyl Sulphide would also have kept the planet warm. The only problem is: It didn't stay warm".
Life caused ice-age
As life emerged on earth it produced increasing amounts of oxygen. With an increasingly oxidizing atmosphere, the sulphur emitted by volcanoes was no longer converted to Carbonyl Sulphide. Instead it got converted to sulphate aerosols: A powerful climate coolant. Johnson and his co-workers created a Computer model of the ancient atmosphere. And the models in conjunction with laboratory experiments suggest that the fall in levels of Carbonyl Sulphide and rise of sulphate aerosols taken together would have been responsible for creating snowball earth, the planetwide ice-age hypothesised to have taken place near the end of the Archean eon 2500 million years ago. And the implications to Johnson are alarming.
"Our research indicates that the distribution and composition of atmospheric gasses swung the planet from a state of life supporting warmth to a planet-wide ice-age spanning millions of years. I can think of no better reason to be extremely cautious about the amounts of greenhouse gasses we are currently emitting to the atmosphere".
Source: University of Copenhagen
Dec 01, 2008 |
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I'd worry less about CO2 and worry more about the many tons of GHGs such as NF3 (nitrogen triflouride) and SF6 (sulfur hexaflouride) that have been ejected into the armosphere as a result of the manufacture of thin-film photovoltaic cells for solar power generation! Nitrogen triflouride is 17,200 times the GHG than is CO2! Sulfur hexaflouride also is a very, very potent GHG, many. many more times potent than CO2.
In essence, the greenies are working to destroy the planet the environuts are trying to save.
I doubt that very highly. To date I have seen very little valid evidence that a difference between a few ppm of CO2 makes much difference in radiative forcing.
Add to this the historical and proxy data that shows that this planet's climate in the Northern Hemisphere was at minimum 4°C to 5°C warmer 1000 years ago than it is today, and this with much lower CO2 levels than at present.
People were swimming for miles in the waters off Greenland and were not dying from hypothermia. Try doing that there nowadays!
In addition, there is other evidence that from Alaska to Norway the climate was several degrees C higher than at present.
See H. H. Lamb, Climate, History and the World, pp. 157-159, for starters. No, the evidence I have seen does not give room enough for CO2 as the central culprit.
In addition, current evidence points to CO2 increasing after the warming trend rather than before, meaning that the evidence does not show CO2 as causitive like IPCC and others like them claim.
And, add to this the fact that manmade GHGs such as NF3 and SF6 will only increase as solar technology continues to be manufactured, there is much more potential for harm than CO2 ever could affect the environment negatively. These are many thousands of times more potent so little is needed.
SF6 really has the potential to really warm up the planet as carbonyl sulfides and so forth were responsible for keeping earth warm at a time when the Sun radiated 30% less energy into space, allowing chemicals to combine and later life to form in the first place during that time.
Bad acronym aside, what mechanism discounts terrestrial volcanic activity and tuirnover from being the warming aspect of the planet?
How exactly would Carbonyl Sulphate provide extra energy to the planet?
Multiple historical texts speak of the climate of the area and the ability to swim in what is now an arctic sea.
How so? The montreal protocol banned CFC manufacture and use to prevent Ozone depletion, meaning it removed a mechanism for planetary cooling. How exactly did it help with radiative forcing budgets?
I gave the reference above, len. It is written by a recognized scientist for the layman.
The author cites the historical evidence for a man who swam for miles between islands in the waters off the shores of Greenland during the time the Norse colonies were on Greenland. He swam to get a sheep and bring it home and prepare it for a guest. The event was recorded in the history record for that time period.
There are other records of other like events in various places as well. But, the crucial stuff deals with conditions in the Arctic at the time which conditions do not exist today--including lack of deep permafrost.
See Lamb, Climate, History and the Modern World, 157-159.
You can get it here:
http://www.amazon...?ie=UTF8&s=books&qid=1250700760&sr=8-1
Read the pages I referenced. Then, read the entire book. You will see that he is not a denier, that he is careful with his facts, and that this historical and other data he references is important to the discussion as a whole.
It is a bit pricey, though, but you get a discount from Amazon if you order now.