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Does cosmic radiation significantly affect earth's climate?

Earth's atmosphere is bombarded by high energy particles from other galaxies called cosmic rays. An interesting theory is that when these particles hit Earth, they help form the type of clouds that reflect sunlight back into space, cooling the atmosphere. Since we know that the Sun forms a shield limiting the amount of cosmic radiation hitting the earth, the theory would imply that when the Sun is stronger, we'd have less cooling clouds, making the atmosphere hotter.

Implications to Other Questions

Is global warming caused primarily by humans?
Does cosmic radiation significantly affect earth's climate?

Experts and Influencers

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Agree
Experts In Science


S. Fred Singer    Head of NIPCC, Astrophysics Professor
Agree
Empirical evidence suggests very strongly that the main cause of warming and cooling on a decadal scale derives from solar activity via its modulation of cosmic rays that in turn affect atmospheric cloudiness.
02 Mar 2008    Source


Jasper Kirkby    Particle Physicist
Mostly Agree
[Sun and cosmic rays] will probably be able to account for somewhere between a half and the whole of the increase in the Earth's temperature that we have seen in the last century.
23 Feb 2007    Source


Neutral
Experts In Climatology


Intergovernmental Panel on Climate Change    (IPCC) Scientific Body formed by U.N.
Neutral
The effects of galactic cosmic rays on the atmosphere (via cloud nucleation) and those due to shifts in the solar spectrum towards the ultraviolet (UV) range, at times of high solar activity, are largely unknown. The latter may produce changes in tropospheric circulation via changes in static stability resulting from the interaction of the increased UV radiation with stratospheric ozone.
01 Jan 2008    Source


Disagree
Experts In Climatology


Gavin Schmidt    Climatologist
Disagree
...we've seen over the last 30 years. There has been no trend in cosmic rays. So any change that there might have been because of cosmic ray impacts on climate can't possibly have an impact on what's been going on... ... [it sounds like a real scientific argument] but it's bogus and you're being led astray.
22 Mar 2007    Source


Jón Egill Kristjánsson    Climatology Professor
Disagree
I think that as a factor in climate change, it's pretty clear that we don't have any indication at this point that [cosmic rays] are important at all.
18 Apr 2008    Source


Encyclopedia


Wikipedia    World's Largest Encyclopedia
Disagree
[A] hypothesis is that magnetic activity of the sun deflects cosmic rays that may influence the generation of cloud condensation nuclei and thereby affect the climate. Other research has found no relation between warming in recent decades and cosmic rays. The influence of cosmic rays on cloud cover is two orders of magnitude lower than needed to explain the observed changes in clouds, and is not a significant contributor to present global warming.
27 Apr 2009    Source



Comments

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0 Points      Benja      22 Jun 2010      Stance on Question: Mostly Disagree
I expect Jon's research will go into the next IPCC report - that cosmic rays have a negligible forcing effect. Many skeptics were relying on cosmic radiation as the mystery variable to explain recent climatic changes. Without a mystery variable, the obvious explanation for recent warming is that it's driven by CO2. In fact, you can't actually reproduce our current climate in any of the climate models if you remove the forcing effect of CO2 from the model. The skeptical hope was that fluctuations in cosmic radiation was the unknown force the models were not taking into account.

Far more damning to the skeptical position however, is the fact that S. Fred Singer in the 2008 NIPCC summary document claims that "Empirical evidence suggests very strongly that the main cause of warming and cooling on a decadal scale derives from solar activity via its modulation of cosmic rays that in turn affect atmospheric cloudiness." Huh? At the time, there was simply a lack of evidence for this view, yet S. Fred Singer had no problem claiming this view was highly likely.

In comparison to the NIPCC, the IPCC's 4th assessment report did precisely the right thing when there was a lack of evidence - it remained neutral on the cause. This however, was conservative of their part - that particular cause had already been indirectly eliminated.