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  (Source: Travelvivi)
But scientists say it did not contribute to global warming today

Lawrence Livermore National Laboratory (LLNL) scientist, along with his team, recently used radiocarbon dating to trace carbon dioxide released to the atmosphere from the deep ocean at the end of the last ice age.

Radiocarbon dating employs the use of radioisotope carbon-14 to figure out the age of ancient and prehistoric carbonaceous materials. This process can be used on materials as old as 62,000 years old. 

Tom Guilderson, a scientist at the LLNL's Center for Accelerator Mass Spectrometry and an author of the study, found that an increase in atmospheric CO2 concentrations corresponded with a decreased amount of carbon-14 relative to carbon-12 in the atmosphere. 

"This suggests that there was a release of very 'old' or low 14/12CO2 from the deep ocean to the atmosphere during the end of the last ice age," said Guilderson. He noted that CO2 release may increase the rate at which ice melts after an ice age. 

Ocean circulation regulates radiocarbon in the atmosphere, and in turn, this regulates the sequestration of carbon dioxide in the deep ocean by atmosphere-ocean carbon exchange. Around 110,000 to 10,000 years ago when the last ice age occurred, lower atmospheric carbon dioxide levels coincided with increased atmospheric radiocarbon concentrations, which have been "credited to great storage of CO2 in a poorly ventilated abyssal ocean." The circulation of the ocean was drastically different back then, and Guilderson admits that he and his team do not fully understand the manner in which carbon was stored in deep ocean at that time. 

The team dated two sediment cores from the subtropic South Pacific near New Zealand and the sub-Antarctic to be approximately 13,000 and 19,000 years old. Guilderson was able to determine when the large CO2 release occurred using the carbon-14 in the cores. Also, he was able to determine the ocean pathway by which it escaped. 

"In this case, the absence of a signal is telling us something important," said Guilderson. "Deeper waters substantially depleted in carbon-14 were drawn to the upper layers and this is the main source of the CO2 during deglaciation. Data suggests that the upwelling of this water occurred in the Southern Ocean, near Antarctica. In our cores off New Zealand, which lie in the path of waters which 'turn over' in the Southern Ocean, we don't find anomalously low carbon-14/12 ratios.

"This implies that either water which upwelled in the Southern Ocean, after 16,500 years ago, had a vigorous exchange with the atmosphere, allowing its 14C-clock to be reset, or the circulation was significantly different than what the current paradigm is. If the paradigm is wrong, then during the glacial and deglaciation, the North Pacific is much more important than we give it credit for."

This carbon dioxide release sped up the melting, but when asked about CO2's contribution to

global warming today, Guilderson said this release of CO2 from the last ice age "is not relevant." But he did mention that he has used radiocarbon dating on CO2 in the atmosphere today, and that isotopic signature shows that use of fossil fuels is what is causing global warming. 

The study was published in the August 26 edition of Nature

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RE: Slow news day
By PaterPelligrino on 8/30/2010 4:22:34 PM , Rating: 3
So Al's a self-aggrandizing hypocrite. Could be he's just taking advantage of the AGW thing to advance his own agenda, that doesn't discredit the science behind global warming. If you want, ditto for Nancy Pelosi.

Its a tax and control scheme - being pushed by those who are in control

It's the rich who are in control, and by and large these people aren't into destroying capitalism and giving away money to Africans just to advance socialist agendas - and please note that I am not referring to humanitarian's who disperse their own money like Gates and Buffett.

Now, if it was TRULY an emergency based on facts, then people would be inclined to do things on their own.

The devil of AGW - if it is correct - is that the damage is to come. People are simply not capable of altering their behavior because of some future, hypothetical threat. Even if AGW were to become incontrovertible, and the damage visible, I fully expect that the vast majority of people will stubbornly resist making any changes whatsoever in their daily lives.

I have no idea whether or not the oil supply is diminishing - there seems to be some controversy on that point. Certainly it's true that we have virtually inexhaustible supplies of cheap coal. But price really isn't the issue here. The question is should we be relying on these carbon-intensive, and polluting resources for our energy needs. Even if AGW is wrong, there are plently of good reasons to move to cleaner energy.

If it is agreed that we should be encouraging alternative energy sources, it's hard to see how that could happen without some kind of price-control coercion.

And about pollution: the reason pollution in our cities is a lot better than it was 20-30 years ago is because the government has coerced industry to clean up it's act - something that never would have happened had corporations been allowed to always chose what was best for their bottom line. Think of how Detroit fought against catalytic converters, coal-fired power plants against laws requiring them to scrub sulfur dioxide from coal exhaust. Are you old enough to remember when the Love River caught fire? The idea that industry will always act in the public good is naive. I've read several articles lately on deteriorating water quality in the US and how industry is fighting tooth and nail to escape EPA control. Governments do have a legitimate right to set social policy.

The problem is - that people aren't buying the doomsday hysteria after the scientists are caught lying and pushing knowingly false extremist positions on purpose, the politicians are caught in corrupt profiteering schemes, and that the unions stand to benefit from government contracts for the "green" agenda.

Yah, that is a problem, and I think it'll take a huge AGW-related catastrophe before people even begin to take global warming seriously. So no catastrophe, nothing for the AGW-deniers to worry about.

However, most of the money pouring into the AGW debate is coming from vested interests intent on protecting their profits. Yesterday, I read an interesting article about the oil-wealth Koch brothers (3rd richest individuals in the States). Not only are they the biggest contributors to the Tea Party movement, they've devoted millions to fighting AGW. Ditto with all the oil and coal companies. The truth is there is serious money on both sides of the issue.

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