Global warming?

[piercehawkeye45]

Originally Posted by xoxoxoBruce

I don't think there has ever been a question that it's warming up.

On what level? There is very little dispute among the scientific community about it but there are a lot of people who still don't believe the Earth is warming. I heard a lot of people this winter taking shots at global warming because their isolated area was supposedly colder than usual.

[Undertoad]

I heard a lot of people last fall attempting to slow down (i.e., harm) the global economy by enacting cap and trade due to the (now discredited) hockey stick graph.

And for the last year, I heard a minority of scientists - a "non-consensus" by some definitions - saying the hockey stick graph would still be created if they put noise - not legitimate data - into the statistical engine that created it in the first place.

I believe warming is happening. 25000 years ago, glaciers threatened only 100 miles north of where I'm sitting right now.

[Shawnee123]

That explains both the penguin, and why you're bitter.

[piercehawkeye45]

Originally Posted by Undertoad

I heard a lot of people last fall attempting to slow down (i.e., harm) the global economy by enacting cap and trade due to the (now discredited) hockey stick graph.

Yes, the some of the questions are how fast and how far with respect to global warming. Research clearly show a temperature increase in the past century backed by other methods but attempting to predict the future is where it gets really sketchy.

[jinx]

And there's lots to consider beyond green house gasses...

The astrophysicist Milutin Milankovitch first proposed that cyclical variations in certain elements of Earth-Sun geometry can cause major changes in Earth's climate. The main variables are eccentricity, obliquity, and precession. Eccentricity refers to the changing shape of Earth's orbit around the Sun, which varies from nearly circular to elliptical over a cycle of about 100,000 years. Obliquity refers to the angle at which Earth's axis is tilted with respect to the plane of its orbit, varying between 22.1 degrees and 24.5 degrees over a 41,000-year cycle. And precession is the gradual change in the direction Earth's axis is pointing, which completes a cycle every 21,000 years.

"Because there are several components of orbital variability, each with lower frequency components of amplitude modulation, there is the potential for unusual interactions between them on long timescales of tens of millions of years," Zachos said. "What we found at 23 million years ago is a rare congruence of a low point in Earth's eccentricity and a period of minimal variation in obliquity."



The result of this rare congruence was a period of about 200,000 years when there was unusually low variability in the planet's climate, with reduced extremes of seasonal warmth and coldness. Earth's orbit was nearly circular, so its distance from the Sun stayed about the same throughout the year. In addition, the tilt of Earth's axis, which gives rise to the seasons, varied less than usual. In other words, the tilt doesn't always vary between the same extremes in its 41,000-year cycles; the obliquity cycle itself varies in amplitude over a longer period of about 1.25 million years. Similarly, the eccentricity cycle peaks every 400,000 years.



The combination of a low-amplitude "node" in the obliquity cycle and a minimum in eccentricity would have caused only several degrees difference in summer temperatures at the poles, but it was probably enough to allow the Antarctic ice sheet to expand, Zachos said.

[classicman]

So ... ... ...
What is Al Gore's plan to alter the earths orbit to avoid the warming?

[xoxoxoBruce]

Originally Posted by piercehawkeye45

On what level? There is very little dispute among the scientific community about it but there are a lot of people who still don't believe the Earth is warming. I heard a lot of people this winter taking shots at global warming because their isolated area was supposedly colder than usual.

What they don't believe, is the scenarios of disaster and doom. The scientists pulling a tw, acting like they must be obeyed, doesn't help their case. Anyone that disputes it, won't get funding.

[piercehawkeye45]

Originally Posted by xoxoxoBruce

What they don't believe, is the scenarios of disaster and doom. The scientists pulling a tw, acting like they must be obeyed, doesn't help their case. Anyone that disputes it, won't get funding.

Its not nearly as bad as other issues, but it seems climate change is turning into another polarized political issue in the US. Conservatives tend to deny global warming using faulty logic and liberals tend to accept man made global warming as gospel. I've heard a good amount of people deny global warming all together just because of a cold winter or because some evidence got denied, which is a step beyond not believing global warming is going to cause the end of the world.

Its turning into another polarizing issue where nothing can get done because both sides are wearing shutters and refuse to believe that they might be wrong.

[classicman]

Well this may offer some insight.

Scientists agree that global temperatures are rising, and so are levels of carbon dioxide. But the immediate impact of human activity on natural climate cycles—from ice-sheet dynamics to wind and ocean currents—remains unclear.

~~~~~~

Much of the current controversy over climate change centers on efforts to reconstruct past temperatures using what is known as "proxy" data from tree rings, harvest records, sea beds and lake sediments. Unlike ice cores, which contain telltale gases and particles from ages ago, the proxy data offer only indirect or fragmentary evidence of climate trends.
~~~~~~~
"Unfortunately many of our proxies have significant errors and are prone to be a slave to assumptions," says climatologist John Christy of the University of Alabama in Huntsville, who has often criticized the IPCC. His research, using temperature readings from NOAA and NASA satellites, has undermined arguments that the atmosphere is warming at an unusual rate.

The ice-core data from Antarctica is "terribly important," Dr. Christy says. "We really need to know what the climate did before we can answer why it did what it did. If it happened before, it will happen again, and probably worse."
~~~~~~
To ensure accuracy, 27 independent laboratories will analyze the ice cores during the next three years. They expect to analyze 40 different trace chemicals related to climate, some in levels down to parts per quadrillion.

At every stage, the scientists must be able to prove that the ice cores haven't been contaminated. They must also make sure the samples stay at minus-20 degrees Celsius or so throughout their 8,000-mile journey to Colorado. Otherwise, the key gases will dissipate.

"Its credibility is of crucial importance," said Thomas Stocker at the University of Bern in Switzerland, a co-chairman of the United Nations working group that assesses data for the IPCC.

Link
Really informative and interesting article.

[Pie]

Originally Posted by classicman

Link
Really informative and interesting article.

<Looks at link: http://online.wsj.com/article/SB10001424052748704655004575114010457906340.html>

Well, there's your problem!

[classicman]

Did you even read it? Sheesh.

Maybe the problem isn't mine?

[classicman]

An underwater ridge could explain why a major glacier in the Antarctic is melting more quickly than ever before, according to a new study.

Scientists used a robot submarine to make a 3D map of the ocean under the ice shelf at the end of the Pine Island Glacier in western Antarctica.

They discovered that the ice was no longer resting on a subsea ridge that had slowed the glacier's slide until the early 1970s.

The discovery means that the glacier's more rapid melting in recent years could be due to the flow of warmer sea water beneath it rather than climate change, as had previously been believed.

Adrian Jenkins, of the British Antarctic Survey, said the study raised 'new questions about whether the current loss of ice from Pine Island Glacier is caused by recent climate change or is a continuation of a longer-term process that began when the glacier disconnected from the ridge'.

Loss of contact with the subsea ridge meant that ice was flowing faster and also thawing more as sea water just above freezing flowed into an ever bigger cavity that now extended 30 km beyond the ridge.

Antarctica is key to predicting the rise in sea levels - it has enough ice to raise sea levels by 187 ft if it all melted.

West Antarctica's thaw accounts for 10 per cent of the recent rise in sea levels, with the Pine Island glacier melting far more quickly in recent decades.
Satellite photographs in the early 1970s had shown a bump on the surface of the ice shelf, indicating the subsea ridge.

That bump has vanished and the submarine found the ridge was now up to 100 metres below the ice shelf.

'We found something very unexpected,' said co-author Pierre Dutrieux, from the British Antarctic Survey (BAS).

'Acoustic instruments on the submarine told us that there was a ridge at the bottom of the ocean, sitting transverse to the flow of ice.'

'Some decades ago, the glacier was sitting on this ridge and the friction of the ridge was restraining the flow of the glacier,' he explained.

'When the glacier became detached from the ridge, the ice flow was able to accelerate significantly.'

Dutrieux said the ice may have started thinning because of some as yet-unknown mechanism linked to climate change, blamed mainly on mankind's use of fossil fuels.

'It could be a shift in the wind, due to a change in climate, that pushed more warm water under the shelf,' he said.

Dr Dutrieux said: 'We now know that there is relatively warm water beneath this floating ice so this warm water could have been able to melt the base of the ice shelf.

'Another process leading to the ice becoming detached from the ridge could have been a change in the water properties that was grinding the shelf from beneath.'

The U.N. panel of climate scientists projected in 2007 that world sea levels could rise by between 7-24 inches by 2100, excluding risks of faster melting in Antarctica and Greenland.

The study was published in the journal Nature Geoscience.

Link
Well that was unexpected. It still doesn't say why/how the water is warming, if it is, perhaps that is common.

[TheMercenary]

Originally Posted by Pie

<Looks at link: http://online.wsj.com/article/SB10001424052748704655004575114010457906340.html>

Well, there's your problem!

Wait, because it is from the WSJ that makes it not a valid source? Is that what you are saying?

[classicman]

This is pretty cool ... still dunno how we are getting the power where its needed, but...

[HungLikeJesus]

Don't worry - in the future all electricity will be transmitted wirelessly.