Posted on 05/04/2009 8:20:01 PM PDT by neverdem
A prolonged lull in solar activity has astrophysicists glued to their telescopes waiting to see what the sun will do next—and how Earth's climate might respond.
The sun is the least active it's been in decades and the dimmest in a hundred years. The lull is causing some scientists to recall the Little Ice Age, an unusual cold spell in Europe and North America, which lasted from about 1300 to 1850.
The coldest period of the Little Ice Age, between 1645 and 1715, has been linked to a deep dip in solar storms known as the Maunder Minimum.
During that time, access to Greenland was largely cut off by ice, and canals in Holland routinely froze solid. Glaciers in the Alps engulfed whole villages, and sea ice increased so much that no open water flowed around Iceland in the year 1695.
But researchers are on guard against their concerns about a new cold snap being misinterpreted.
"[Global warming] skeptics tend to leap forward," said Mike Lockwood, a solar terrestrial physicist at the University of Southampton in the U.K. (Get the facts about global warming.)
He and other researchers are therefore engaged in what they call "preemptive denial" of a solar minimum leading to global cooling.
Even if the current solar lull is the beginning of a prolonged quiet, the scientists say, the star's effects on climate will pale in contrast with the influence of human-made greenhouse gases such as carbon dioxide (CO2).
"I think you have to bear in mind that the CO2 is a good 50 to 60 percent higher than normal, whereas the decline in solar output is a few hundredths of one percent down," Lockwood said. "I think that helps keep it in perspective."
(Related: "Don't Blame Sun for Global Warming, Study Says.")
Local Cooling
For hundreds of years scientists have used the number of observable sunspots to trace the sun's roughly 11-year cycles of activity.
Sunspots, which can be visible without a telescope, are dark regions that indicate intense magnetic activity on the sun's surface. Such solar storms send bursts of charged particles hurtling toward Earth that can spark auroras, disrupt satellites, and even knock out electrical grids.
In the current cycle, 2008 was supposed to have been the low point, and this year the sunspot numbers should have begun to climb.
But of the first 90 days of 2009, 78 have been sunspot free. Researchers also say the sun is the dimmest it's been in a hundred years.
The Maunder Minimum corresponded to a profound lull in sunspots—astronomers at the time recorded just 50 in a 30-year period.
If the sun again sinks into a similar depression, at least one preliminary model has suggested that cool spots could crop up in regions of Europe, the United States, and Siberia.
During the previous event, though, many parts of the world were not affected at all, said Jeffrey Hall, an astronomer and associate director at Lowell Observatory in Flagstaff, Arizona.
"Even a grand minimum like that was not having a global effect," he said.
Wild Cards and Uncertainties
Changes in the sun's activity can affect Earth in other ways, too.
For example, ultraviolet (UV) light from the sun is not bottoming out the same way it did during the past few visual minima.
"The visible light doesn't vary that much, but UV varies 20 percent, [and] x-rays can vary by a factor of ten," Hall said. "What we don't understand so well is the impact of that differing spectral irradiance."
Solar UV light, for example, affects mostly the upper layers of Earth's atmosphere, where the effects are not as noticeable to humans. But some researchers suspect those effects could trickle down into the lower layers, where weather happens.
In general, recent research has been building a case that the sun has a slightly bigger influence on Earth's climate than most theories have predicted.
Atmospheric wild cards, such as UV radiation, could be part of the explanation, said the University of Southampton's Lockwood.
In the meantime, he and other experts caution against relying on future solar lulls to help mitigate global warming.
"There are many uncertainties," said Jose Abreu, a doctoral candidate at the Swiss government's research institute Eawag.
"We don't know the sensitivity of the climate to changes in solar intensity. In my opinion, I wouldn't play with things I don't know."
| © 1996-2008 National Geographic Society. All rights reserved. |
hese idiots are beyond embarrassment. If they weren’t they be afraid to show their face in public. I know I couldn’t.
They just know no shame.
Ok, that has to be the stupidest statement ever printed.
I believe the reference to CO2 being higher than “normal” is eroneous. It has been higher in Earth’s history.
And the argumnt that 50 or 60% more co2 has a greater effect than a tiny change in solar activity is laughable. Similar “tiny” solar changes caused the little ice age because the Sun’s influence is so powrful.
"We don't know the sensitivity of the climate to changes in solar intensity. In my opinion, I wouldn't play with things I don't know."
It's a shame Al Gore is too damned stupid to understand this.
1% of a large number is a much greater influence than 50% of a small number.
As if the solar irradiation were the problem, rather than the magnetic effects and solar wind.
Dipsh*t.
Wow! What backward logic. If 50 years Global Warming coincident with 50-60% rise in CO2 has been wiped out in the last eight years by solar output declining 0.02% logic says that the Sun's output variability is 2,500 times as powerful as CO2 concentrations.
Now you are confusing the matter with facts and data. /s
Idiots!!! The sun is the source of almost all the surface and atmospheric heating. Using their logic, if the sun stopped shining it would only make a minor difference in the temperature of the earth.
“preemptive denial”
ROFL.
With the hot air and lies of Gore and Hansen on their side, the alarmists were getting ready to disenfranchise the sun.
Some of these people don't even realize it's a star, because it's the "Sun".
I met some of these people that thought the moon generated it's own light, as they had not a clue it was just reflecting starlight. These people are totally wrapped up in their own tiny political realm, and so convinced external forces do not have any effect on this planet...We'll, they are just beyond help.
Sorry, but they're not the biggest deniers in the game. The AGW alarmists are.
Which proves how little C02 plays in our climate, while the Sun's "few hundredths of one percent down" truly does affect our climate.
What...no more worry about Global Warming? Algore must have stopped breathing and so now the hot air on this planet is - Allgone !
Of course, for the alarmists, there are no such things as rationalism and empiricism. They deal only in apocalyptic predictions and emotional power plays. It'll be interesting to see how many of this noisome AGW crowd will veer to the other extreme if and when the current cooling trend persists.
I rarely comment on people like Gore. Not worth my time. But he’s like the weird little peddler, rolling into the small town on his wagon, with his elixirs, and potions that will keep the spooks away. The term snake oil salesmen, is way to nice of term for that AH.
This freak is all about control and his selective political game.
It is really fun to remind them that it is a thermonuclear reactor and that we are bathed in its radiation.
Global warming - Little Ice Age...... which is it? What’s the diff? We can’t expect them to just give our credit cards back.
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