Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates?

  title={Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates?},
  author={Jeffery R. Pierce and Peter J. Adams},
  journal={Geophysical Research Letters},
  • J. Pierce, P. Adams
  • Published 1 May 2009
  • Physics, Environmental Science
  • Geophysical Research Letters
Although controversial, many observations have suggested that low‐level cloud cover correlates with the cosmic ray flux. Because galactic cosmic rays have likely decreased in intensity over the last century, this hypothesis, if true, could partly explain 20th century warming, thereby upsetting the consensus view that greenhouse‐gas forcing has caused most of the warming. The “ion‐aerosol clear‐air” hypothesis suggests that increased cosmic rays cause increases in new‐particle formation, cloud… 
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