Study shines new light on Sun's role in Earth's climate


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London, England (CNN) -- A new study has shed light on the sun's impact on the Earth's climate, confounding current thinking about solar cycles and how they influence temperatures on Earth.

Previously scientists had thought that radiation reaching the Earth rises and falls in line with the Sun's activity, which during the 11-year solar cycle goes though periods of low and high activity.

But research by Imperial College, London and the University of Colorado in the U.S. examining solar radiation levels from 2004 to 2007 -- a period of declining solar activity -- revealed that levels of visible radiation reaching the Earth actually increased during the period.

Using data collected by NASA's SORCE (SOlar Radiation and Climate Experiment) satellite, which launched in 2003, the scientists were able to scrutinize the full solar spectrum -- x-ray, ultraviolet (UV), visible (VR), near-infrared, and total solar radiation -- and compare it to earlier, less comprehensive data.

Joanna Haigh, leader author of the study published in the journal Nature told CNN: "What the data has shown, rather unexpectedly, is that the decline in ultra-violet radiation is much larger than anticipated. But more surprisingly the visible radiation actually increased as solar activity was declining."

Haigh, a professor of atmospheric physics, says that UV radiation is mostly absorbed in the stratosphere but visible radiation gets through to the earth's surface. The observed increase in VR, despite declining solar activity, may have caused small rises in temperature.

"The sun has been behaving very strangely. Its magnetic activity is lower than it has been for several hundred years, perhaps. And so the fact that it's doing strange things in its spectrum is perhaps not that unexpected," she said.

"They [the solar cycles] are contributing nothing to long-term global warming," she said, "and it has no bearing on what we understand about greenhouse gases and their influence on climate."

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Wow, but what can you say? The sun is a mass of incandescent gas, a gigantic nuclear furnace. Where hydrogen is changed into helium at a temperature of millions of degrees.

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^ Ah yeah, but where does the hydrogen come from ? What keeps it from being consumed at once ?

How does hydrogen survive 'millions of degrees' ?

I see the Sun/stars as being far more complicated than presently understood. ;)

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^ Ah yeah, but where does the hydrogen come from ? What keeps it from being consumed at once ?

How does hydrogen survive 'millions of degrees' ?

I see the Sun/stars as being far more complicated than presently understood. ;)

It came from whatever gases/elements were present before the sun was formed. The reason the sun doesn't burn out so quickly is due to the sheer amount of hydrogen. Each second, the sun converts millions of metric tons of hydrogen into helium. There's a lot that we know already and of course, there's a lot that we don't know.

As for the sun's effect on weather, I'd say that's a subject that scientists know little of.

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London, England (CNN) -- A new study has shed light on the sun's impact on the Earth's climate, confounding current thinking about solar cycles and how they influence temperatures on Earth.

Er, not quite. This is just for a 3-year period, while a full solar cycle is 11 years. How about we ask the scientists themselves what this report actually means?

"However, they caution that three years of data are not enough to draw firm conclusions about long-term trends."

"But, they add, the research does not challenge the role of humanity's production of greenhouse gases as the dominant long-term driver of modern-day climate change."

"What we can't really do at this stage is to extrapolate from this three-year period to any longer period - we can't even say that [what we've seen] has happened on previous solar cycles"

"This new study does not change that basic picture, Professor Haigh said, despite the claims of some observers that solar factors have been underestimated as a cause of modern-day climate change."

"If the climate were affected in the long term, the Sun should have produced a notable cooling in the first half of the 20th Century, which we know it didn't"

I notice that AGW denialists are jumping all over this one, but as always, for no reason. Strange how most reports on this leave out the parts about what the report actually shows (and doesn't show).

As for the sun's effect on weather, I'd say that's a subject that scientists know little of.

Actually, scientists know quite a bit about the sun's influence on the climate.

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There's a lot that we know already and of course, there's a lot that we don't know.

The bad thing is the lot we don't know has a way of coming up and biting us in the butt when we least expect it.

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^ Ah yeah, but where does the hydrogen come from ? What keeps it from being consumed at once ?

How does hydrogen survive 'millions of degrees' ?

I see the Sun/stars as being far more complicated than presently understood. ;)

Find Stephen Hawkings Universe somewhere to watch.

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"The sun has been behaving very strangely. Its magnetic activity is lower than it has been for several hundred years, perhaps. And so the fact that it's doing strange things in its spectrum is perhaps not that unexpected," she said.

The sun is going to explode! :unsure:

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