Please Scroll Down to See Forums Below
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

napsgear
genezapharmateuticals
domestic-supply
puritysourcelabs
Research Chemical SciencesUGFREAKeudomestic
napsgeargenezapharmateuticals domestic-supplypuritysourcelabsResearch Chemical SciencesUGFREAKeudomestic

Cosmic Rays may have much more to do with global warming than humans

redguru

New member
Cosmic rays blamed for global warming

By Richard Gray, Science Correspondent, Sunday Telegraph
Last Updated: 1:08am GMT 11/02/2007

Man-made climate change may be happening at a far slower rate than has been claimed, according to controversial new research.

Scientists say that cosmic rays from outer space play a far greater role in changing the Earth's climate than global warming experts previously thought.

In a book, to be published this week, they claim that fluctuations in the number of cosmic rays hitting the atmosphere directly alter the amount of cloud covering the planet.

warm11.gif

How cosmic rays could seed clouds diagram

High levels of cloud cover blankets the Earth and reflects radiated heat from the Sun back out into space, causing the planet to cool.

Henrik Svensmark, a weather scientist at the Danish National Space Centre who led the team behind the research, believes that the planet is experiencing a natural period of low cloud cover due to fewer cosmic rays entering the atmosphere.

This, he says, is responsible for much of the global warming we are experiencing.

He claims carbon dioxide emissions due to human activity are having a smaller impact on climate change than scientists think. If he is correct, it could mean that mankind has more time to reduce our effect on the climate.

The controversial theory comes one week after 2,500 scientists who make up the United Nations International Panel on Climate Change published their fourth report stating that human carbon dioxide emissions would cause temperature rises of up to 4.5 C by the end of the century.

Mr Svensmark claims that the calculations used to make this prediction largely overlooked the effect of cosmic rays on cloud cover and the temperature rise due to human activity may be much smaller.

He said: "It was long thought that clouds were caused by climate change, but now we see that climate change is driven by clouds.

"This has not been taken into account in the models used to work out the effect carbon dioxide has had.
advertisement

"We may see CO2 is responsible for much less warming than we thought and if this is the case the predictions of warming due to human activity will need to be adjusted."

Mr Svensmark last week published the first experimental evidence from five years' research on the influence that cosmic rays have on cloud production in the Proceedings of the Royal Society Journal A: Mathematical, Physical and Engineering Sciences. This week he will also publish a fuller account of his work in a book entitled The Chilling Stars: A New Theory of Climate Change.

A team of more than 60 scientists from around the world are preparing to conduct a large-scale experiment using a particle accelerator in Geneva, Switzerland, to replicate the effect of cosmic rays hitting the atmosphere.

They hope this will prove whether this deep space radiation is responsible for changing cloud cover. If so, it could force climate scientists to re-evaluate their ideas about how global warming occurs.

Mr Svensmark's results show that the rays produce electrically charged particles when they hit the atmosphere. He said: "These particles attract water molecules from the air and cause them to clump together until they condense into clouds."

Mr Svensmark claims that the number of cosmic rays hitting the Earth changes with the magnetic activity around the Sun. During high periods of activity, fewer cosmic rays hit the Earth and so there are less clouds formed, resulting in warming.

Low activity causes more clouds and cools the Earth.

He said: "Evidence from ice cores show this happening long into the past. We have the highest solar activity we have had in at least 1,000 years.

"Humans are having an effect on climate change, but by not including the cosmic ray effect in models it means the results are inaccurate.The size of man's impact may be much smaller and so the man-made change is happening slower than predicted."

Some climate change experts have dismissed the claims as "tenuous".

Giles Harrison, a cloud specialist at Reading University said that he had carried out research on cosmic rays and their effect on clouds, but believed the impact on climate is much smaller than Mr Svensmark claims.

Mr Harrison said: "I have been looking at cloud data going back 50 years over the UK and found there was a small relationship with cosmic rays. It looks like it creates some additional variability in a natural climate system but this is small."

But there is a growing number of scientists who believe that the effect may be genuine.

Among them is Prof Bob Bingham, a clouds expert from the Central Laboratory of the Research Councils in Rutherford.

He said: "It is a relatively new idea, but there is some evidence there for this effect on clouds."
 
This is the first controlled experiment that shows the effects of cosmic rays on the earth's weather patterns and total cloud cover.
 
RedGuru said:
Mr Svensmark claims that the number of cosmic rays hitting the Earth changes with the magnetic activity around the Sun. During high periods of activity, fewer cosmic rays hit the Earth and so there are less clouds formed, resulting in warming.

Muons are polarized? I haven't looked into this for a while... might be of some merit.

We can estimate pretty well the large amounts of CO2 we push into the air on a regular basis, so I wonder why there's too many variables to extrapolate the damage done by using a controlled laboratory experiment with O3.

I wonder if muons are affected by the changing of the Earth's magnetic field? Or if that's too weak with respect to the sun?

A novel, interesting viewpoint, to be sure. I'm curious to see what further research and studies reveal.



:cow:
 
"Cosmic rays are composed mainly of bare nuclei, roughly 87% protons, 12% alpha particles (helium nuclei) and most of the rest being made up of heavier atomic nuclei with relative abundances comparable to those found in the Sun. Electrons, gamma rays, and very high-energy neutrinos also make up a much smaller fraction of the cosmic radiation" (1). It appears muons do not interact heavily with the atmosphere, which is why they are used in CR detection. "Coronal mass ejections (CMEs) can temporarily lower the local cosmic ray levels, and radiation from CMEs is easier to shield against than cosmic rays". So I'm guessing that the sun's activity can be correlated to the amount of CRs impacting Earth. The energy and radiation given off by the sun would vastly overpower that of the Earth's weakly fluctuating EM field.

"Cosmic rays have been experimentally determined to be a potential modulating factor in cloud formation and by theoretical extrapolation to be a contributor of global warming" (2). "It has been shown that cosmic rays have a catalytic effect on the nucleation of cloud droplets. It is similar in concept to the operating principles of the Wilson cloud chamber, however acting on a global scale, where earth's atmosphere acts as the cloud chamber and the cosmic rays catalyze the production of Cloud condensation nuclei. Proposed mechanisms for this climate interaction are, Ion Mediated Nucleation, and through an indirect effect on current flow density in the Global electric circuit (see Tinsley 2000, and F. Yu 1999). The theories use notions of aerosols, surface charge, and atmospheric current densities. Lately published work by Lumbjorg (The cooling stars) claims to have produced signifigant aerosols for CCN in controld simulations of earths atmosphere using energy inputs to simulate GCR. Also the latest Svensmark paper claims to suggest a link between GCR variation and the cambrian explosion. GCR climate signals have been identified in atmospheric parameters such as high latitude precipitation (Todd & Kniveton) and originally [and more tenuously] svensmarks annual cloud cover variations, which were proven more correlated to GCR variation than direct solar variation."

"Galactic cosmic rays (GCRs) are the high-energy particles that flow into our solar system from far away in the Galaxy. GCRs are mostly pieces of atoms: protons, electrons, and atomic nuclei which have had all of the surrounding electrons stripped during their high-speed (almost the speed of light) passage through the Galaxy. Cosmic rays provide one of our few direct samples of matter from outside the solar system. Galactic cosmic rays differ in their composition and origin from solar cosmic rays, which are mostly protons and helium nuclei accelerated by solar activity. The mean energies of galactic cosmic rays also are much higher than the energies of solar cosmic rays."

"The magnetic fields of the Galaxy, the solar system, and the Earth have scrambled the flight paths of these particles so much that we can no longer point back to their sources in the Galaxy. If you made a map of the sky with cosmic ray intensities, it would vary according to variations in the magnetic field. So we have to determine where cosmic rays come from by indirect means" (3).

shower.png


"The cosmic rays will hardly ever hit the ground but will collide (interact) with a nucleus of the air, usually several ten kilometers high. In such collisions, many new particles are usually created and the colliding nuclei evaporate to a large extent.

Most of the new particles are pi-mesons (pions). Neutral pions very quickly decay, usually into two gamma-rays. Charged pions also decay but after a longer time. Therefore, some of the pions may collide with yet another nucleus of the air before decaying, which would be into a muon and a neutrino. The fragments of the incoming nucleus also interact again, also producing new particles.

The gamma-rays from the neutral pions may also create new particles, an electron and a positron, by the pair-creation process. Electrons and positrons in turn may produce more gamma-rays by the bremsstrahlung mechanism" (4).

"Because cosmic rays are electrically charged they are deflected by magnetic fields, and their directions have been randomized, making it impossible to tell where they originated. However, cosmic rays in other regions of the Galaxy can be traced by the electromagnetic radiation they produce. Supernova remnants such as the Crab Nebula are known to be a source of cosmic rays from the radio synchrotron radiation emitted by cosmic ray electrons spiraling in the magnetic fields of the remnant. In addition, observations of high energy (10 MeV - 1000 MeV) gamma rays resulting from cosmic ray collisions with interstellar gas show that most cosmic rays are confined to the disk of the Galaxy, presumably by its magnetic field" (5).

Thus, one problem of the research presented in the article,

RedGuru said:
A team of more than 60 scientists from around the world are preparing to conduct a large-scale experiment using a particle accelerator in Geneva, Switzerland, to replicate the effect of cosmic rays hitting the atmosphere.

Is that we cannot replicate but the lowest energy cosmic rays even in our largest particle accelerators.

Further, the inability to locate sources of high-energy CR and the necessity of extrapolation will be one hurdle for the researchers to jump in presenting evidence for their case.

It seems like solid research, but it's in an area of HEP where we don't have all the details, and theoretical research is limited by the energies we are capable of achieving in labs. I bet they can find some correlations, but it will be difficult in ascertaining this from purely empirical bases.



:cow:


1) http://en.wikipedia.org/wiki/Cosmic_rays
2) Henrik Svensmark, Jens Olaf Pepke Pedersen, Nigel Marsh, Martin Enghoff and Ulrik Uggerhøj, "Experimental Evidence for the role of Ions in Particle Nucleation under Atmospheric Conditions", Proceedings of the Royal Society A, (Early Online Publishing), 2006
3) http://en.wikipedia.org/wiki/Galactic_cosmic_ray
4) http://www.mpi-hd.mpg.de/hfm/CosmicRay/Showers.html
5) http://www.srl.caltech.edu/personnel/dick/cos_encyc.html
 
Interesting....
 
I know there accelerators out there with higher energies than CERN, but they're only able to take small incremental steps now, as we reach energies at the limit of what can be produced here on Earth.

It looks like they will not be able to take into account all CRs, and many of the lower-energy CRs seem to be produced from our sun. Further, given the CRs polarity and interaction with any EM field, including the Earth's, it seems like it would be difficult to ascertain whether or not the CRs they track are from the sun or from extra-solar sources, since the earth's EM field can change the vector of incoming CRs drastically.

Detection via Neutrino detectors would be of little value as well, as there is little ability to tell whether they came from one side or traveled through the Earth from the other. The only reason we figured out the neutrinos from SN1987A were from a supernova was that it was easily visable in the sky.



:cow:
 
Top Bottom