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View Full Version : Ocean Current Shutdown May Be Gradual, Not Sudden


Mousehound
07-19-2009, 07:56 PM
ScienceDaily (July 17, 2009) The findings of a major new study are consistent with gradual changes of current systems in the North Atlantic Ocean, rather than a more sudden shutdown that could lead to rapid climate changes in Europe and elsewhere.

The research, based on the longest experiment of its type ever run on a "general circulation model" that simulated the Earth's climate for 21,000 years back to the height of the last Ice Age, shows that major changes in these important ocean current systems can occur, but they may take place more slowly and gradually than had been suggested.

The newest findings, to be published July 17 in the journal Science, are consistent with other recent studies that are moving away from the theory of an abrupt "tipping point" that might cause dramatic atmospheric temperature and ocean circulation changes in as little as 50 years.

"Research is now indicating that this phenomenon may happen, but probably not as a sudden threshold we're crossing," said Peter Clark, a professor of geosciences at Oregon State University. "For those who have been concerned about extremely abrupt changes in these ocean current patterns, that's good news.

"In the past it appears the ocean did change abruptly, but only because of a sudden change in the forcing," he said. "But when the ocean is forced gradually, such as we anticipate for the future, its response is gradual. That would give ecosystems more time to adjust to new conditions."

The findings do not change broader concerns about global warming. Temperatures are still projected to increase about four to 11 degrees by the end of this century, and the study actually confirms that some of the world's most sophisticated climate models are accurate.

"The findings from this study, which also match other data we have on recorded climate change, are an important validation of the global climate models," Clark said. "They seem to be accurately reflecting both the type and speed of changes that have taken place in the past, and that increases our ability to trust their predictions of the future."

A particular concern for some time has been the operation of an ocean current pattern called the Atlantic meridional overturning circulation, or AMOC. This current system is part of what keeps Europe much warmer than it would otherwise be, given its far northern latitudes, and there is evidence that it has "shut down" with some regularity in Earth's past - apparently in response to large influxes of fresh water, and sometimes quite rapidly.

"Our data still show that current is slowing, and may decline by 30 percent by the end of this century," Clark said. "That's very significant, and it could cause substantial climate change. But it's not as abrupt as some concerns that it could shut down within a few decades."

Climate changes, Clark said, are actually continuing to occur somewhat more rapidly than had been predicted in recent years. Arctic Sea ice is both thinning and shrinking, and atmospheric carbon dioxide levels are going up faster than had been projected by the Intergovernmental Panel on Climate Change.

Please read the full article here:
http://www.sciencedaily.com/releases/2009/07/090716141142.htm

Ought Six
07-19-2009, 09:30 PM
Another global warming disaster theory appears to be total bunk. That is not surprising, when you consider that during warmer times in recent history, mankind flourished.

Oric
07-20-2009, 01:38 AM
warmer weather assisted the earlier societies, it may not be so today. majority of the population lives in "temperate zones". A shift in these zones may require massive relocation.

Ought Six
07-20-2009, 01:48 AM
o:"A shift in these zones may require massive relocation."People live in climates from the Mojave desert to the Arctic. Nobody will need to be relocated if changes do occur, especially if they are gradual. People are extremely adaptable.

Oric
07-20-2009, 02:00 AM
adaptable yes .. but we can not adapt to lack of clean water for example. If a megacity finds its reservoirs depleted, its citizens will flock away ... This is some type of adaptation and exactly the relocation event i am talking about. Of course a city far north will have warmer winters and recieve more population. I am not calling GW a global disaster but a global menace for most

Ought Six
07-20-2009, 02:05 AM
r:"adaptable yes .. but we can not adapt to lack of clean water for example. If a megacity finds its reservoirs depleted, its citizens will flock away ... This is some type of adaptation and exactly the relocation event i am talking about"Yes, actually we can. The Saudi and others have. Desalinization is getting cheaper and more scalable all the time, and vast majority of megacities are very close to the ocean or inland seas. More ways to use less water while maintaining a good lifestyle are being discovered all the time. And remember, we are talking about gradual changes here, so there is time to build new infrastructure as the problems manifest, *if* they manifest.

Oric
07-20-2009, 05:20 AM
O6 : desalinization is not the answer ... Saudis and others (?) equal to cheap energy resources, which many countries do not have .. Also there are a lot of inland megacities without access to lakes or seas. Anyway, gradual changes will mean gradual immigration to new climate zones.

Ought Six
07-20-2009, 02:16 PM
o:

Like I said, the technology is getting cheaper and more scaleable all the time. That means it is becoming affordable on a large scale.

You are engaging in static thinking; assuming we will only have today's level of technology to deal with tomorrow's problems.

Oric
07-21-2009, 05:30 AM
not exactly static thinking o6 .. I take into account that energy will be more expensive therefore mankind will put survival into priority rather than maintaining a level of comfort (like desalinizing .. We would prefer to move rather than stay and use energy to keep up our status quo) .. Unless controllable fusion is achieved ...

Samen
07-21-2009, 07:18 AM
The below post shows the two halves of the coin

1. A new tomato gene found by scientist can feed the world (science finds a way to feed)

2. The world population will double in 50 years ( science has the means to stop it but cant)

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Australian scientists find tomato gene to feed millions
www.chinaview.cn 2009-07-21 15:07:41

SYDNEY, July 21 (Xinhua) -- Australian scientists have found a way to boost crop yields that could help feed and clothe millions of people in a time of climate crisis, according to a report from Australian Associated Press on Tuesday.

Researchers at the University of Newcastle have found that by knocking out a gene from the genetic code of a tomato plant, it grows sweeter fruit and longer-lasting leaves.

Yong-Ling Ruan, from the University's School of Environmental and Life Sciences, said the same technique could be used in a range of plants to boost crop yield and shelf-life.

"With predictions the global population may double over the next 50 years, scientists are concerned about the pressure on the world's natural resources," Ruan said.

"Faced with the impact of climate change and population increases on food supply, our research is helping to meet the challenge of how to sustain and improve crop yield and quality."

Ruan said scientists would need at least another five years to take the technique from the lab to the paddock.

The research was conducted at the Australia-China Research Center for Crop Improvement - a joint initiative of the Universityof Newcastle and the Zhejiang Academy of Agricultural Sciences in Hangzhou, China.

http://news.xinhuanet.com/english/2009-07/21/content_11744891.htm

Ought Six
07-21-2009, 04:50 PM
S:"2. The world population will double in 50 years ( science has the means to stop it but cant)"This is again static thinking in the form of a linear projection. If you go back and read the old book, The Population Bomb, you will see the same failed meme. In fact, I suspect that in fifty years, the problem will be a falling human population. Low fertility rates and social changes like the ones we have already seen in the developed world are slowly starting to take hold in places like China and India. Pollution is also damaging fertility in those areas. Only Africa maintains a steady high rate of population increase, in spite of a fast-increasing death rate from AIDS.

Sysiphus
07-21-2009, 05:34 PM
Everywhere the Pill goes, the birthrate falls. If it were not for the Catholic Church, and lack of access to contraceptives in Africa, the rate of population growth would indeed be falling on a global basis.

Ought Six
07-21-2009, 07:26 PM
Since the Pope recently declared that condoms make the AIDS problem worse, we can probably look forward to the AIDS epidemic in Africa reaching the point where the death rate meets or exceeds the birth rate, thus solving the population problem. I beginning to think that His Holiness's striking resemblance to the evil Emperor Palpatine in the StarWars movies may not be entirely coincidental.

http://www.instructables.com/files/deriv/FAS/EYI3/FFNEHLJO/FASEYI3FFNEHLJO.MEDIUM.gif