Paper: CO2 Helped Prevent Snowball Earth
30 November 2008
Carbon dioxide may have played a vital role in helping ancient Earth to escape from complete glaciation, according to scientists in a paper to be published in the journal Nature Geoscience. The authors from Imperial College London claim that the Earth never froze over completely during the Cryogenian Period, about 840 to 635 million years ago.
This is contrary to the Snowball Earth hypothesis, which envisages a fully frozen Earth that was locked in ice for many millions of years as a result of a runaway chain reaction that caused the planet to cool.
What enabled the Earth to escape from a complete freeze is not certain, but the UK scientists in their review point to recent research carried out at the University of Toronto. This speculates that the advancing ice was stalled by the interaction of the physical climate system and the carbon cycle of the ocean, with carbon dioxide playing a key role in insulating the planet.
The Toronto scientists say that as Earth’s temperatures cooled, oxygen was drawn into the ocean, where it oxidized organic matter, releasing the greenhouse gas carbon dioxide into the atmosphere. The review’s lead author, Professor Phillip Allen, from Imperial College London’s Department of Earth Science and Engineering, says that something must have kept the planet’s equatorial oceans from freezing over.
In the climate change game, carbon dioxide can be both saint and sinner. These days we are so concerned about global warming and the harm that carbon dioxide is doing to our planet. However, approximately 600 million years ago, this greenhouse gas probably saved ancient Earth and its basic life forms from an icy extinction.
—Phillip Allen
Professor Allen, whose previous research has found evidence demonstrating hot and cold cycles in the Cryogenian period, says a plethora of papers has been published and much debate has been devoted to the Snowball Earth theory since it was originally proposed.
Sedimentary rocks deposited during these cold intervals indicate that dynamic glaciers and ice streams continued to deliver large amounts of sediment to open oceans. This evidence contradicts the Snowball Earth theory, which suggests the oceans were frozen over. Yet, many scientists still believe Snowball Earth to be correct.
There is so much about Earth’s ancient past that we don’t know enough about. So it is really important that climate modellers get their targets right. They need to build into their calculations a warmer planet, with open oceans, despite lower levels of solar radiation at this time. Otherwise, climate models about the Earth’s distant past are aiming for a target that never existed.
—Phillip Allen
During the Cambrian Period (600M years) core samples show atmospheric CO2 to be somewhere between 5,000 and 7,000ppm. While this level of CO2 may have trapped solar heat far better than at present - and prevented cryogenation of the Earth's crust - we know very little of other climatic variables e.g. ocean and forest sequestration and outgassing.
Let's hope that this conclusion is not warped by wily climatologists to suggest that presently elevating CO2 0.0385% atmosphere will help stave off cooling trend over the next 30 years.
Posted by: Stew Dent | 30 November 2008 at 05:46 PM
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"...about 840 to 635 million years ago. "
I HATE what those 840 to 635 million year old SUV's did to our environment!!! They should have been BANNED back then.
What?!?! The Earth's climate has been changing with out input from man and EEeeeeeviillll SUVs? The heck you say?!?! Algore says that this is ALL man's fault and without government taking over economies and forcing people to ride bicycles were all gonna die!!! From Global Warming... No, wait, from Global Cooling... No, wait, from Climate Change!!! Yeah, that's it. Climate Change. Since the climate is always changing we can never be incorrect by panicking over Climate Change.
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Posted by: Mr. Environment | 30 November 2008 at 07:33 PM
Organic persons are the main problem of the earth because they like SUVs among other things. Virtual persons embodied in a few cubic centimeters of silicon need less energy, and in fact a few virtual persons could be stored on disc drives waiting to be swapped into the silicon when needed. The silicon can be powered by extreme low carbon Rubbia Reactors, not CANDU ones. ..HG..
Posted by: Henry Gibson | 30 November 2008 at 08:09 PM
Yep. But why so darned much silicon is needed? Once we finally outlaw carbon-based lifeforms - the world will be a bitter place. No strife. No stress. No SUVs. Finally, the eco-terrorestrials regurgitate their dream!
Posted by: iRobought | 30 November 2008 at 11:31 PM
how much C02 would a virtual SUV spew?
Posted by: | 01 December 2008 at 06:49 AM
What a bunch of pointless posts!
Posted by: GdB | 01 December 2008 at 12:48 PM
Carbon Dioxide (CO2) is Not Pollution
http://www.populartechnology.net/2008/11/carbon-dioxide-co2-is-not-pollution.html
"CO2 for different people has different attractions. After all, what is it? - it’s not a pollutant, it’s a product of every living creature’s breathing, it’s the product of all plant respiration, it is essential for plant life and photosynthesis, it’s a product of all industrial burning, it’s a product of driving – I mean, if you ever wanted a leverage point to control everything from exhalation to driving, this would be a dream. So it has a kind of fundamental attractiveness to bureaucratic mentality." - Richard S. Lindzen, Ph.D. Professor of Atmospheric Science, MIT
Posted by: Andrew | 02 December 2008 at 04:07 AM
For discussion of the facts of global warming by scientists see
Posted by: richard schumacher | 02 December 2008 at 06:35 AM
http://realclimate.org
Posted by: richard schumacher | 02 December 2008 at 06:35 AM
"What a bunch of pointless posts! "
What a pointless post about a bunch of pointless posts!
Posted by: Mr. Environment | 02 December 2008 at 12:26 PM
"What a bunch of pointless posts! "
What a pointless post about a bunch of pointless posts!
Posted by: Mr. Environment | 02 December 2008 at 12:26 PM
Mr. Environment or should I call you Stan Peterson. We have not heard from him since you started posting.
You need a certain amount of water in your lungs for them to work properly. If we put an extra liter of water in your lungs very quickly you would stop breathing and no longer post on this site. Is water in healthy places at healthy levels a pollutant? No it isn't. The same is true about CO2 and several other compounds and elements. Not enough and you die and too much and you die. Within a certain range you live very well.
Posted by: tom deplume | 02 December 2008 at 02:18 PM
...about as pointless as a bunch of pointless posts in the yard, by which I mean they are blunt...
Posted by: Pan Steterson | 03 December 2008 at 09:50 AM
CO2 of course is a waste product. In common oxidizing reactions in which carbohydrates are oxidized in all metabolic processes, it is the waste expelled. In burning something, it is the waste. Just trying to confuse the matter by looking at the recycling of the CO2 waste by photosynthesis is just obfuscating the issue. People aren't plants. Plants release CO2 in lower lighted or dark conditions just like every other metabolizing organism. CO2 is a waste product of civilization and the processes of all life.
Some of these comments are the worst. The story is basically about how CO2 played a roll in ameliorating and reversing the cool down of the earth in this period. And there are comments about SUVs in the past or whatever. This is just another story of the fact that CO2, a greenhouse gas, plays a role in environemntal conditions. It is germaine because in today's world, humans are artificially jacking it up when in the past, natural conditions jacked it up.
CO2 is a known infrared blocker since Arrhenius, over a century ago, when he proposed massive coal fires to artificially warm the climate of Sweden by geo-engineering an artificial global warming, totally misquided by the naivete that warming would only bring goog effects or that the effects would be good for Sweden and he didn't care what heppened to anywhere else..
Get the parallels?
Posted by: aym | 03 December 2008 at 10:56 AM