Cosmic Rays [Allegedly] too Wimpy to Influence Climate | Universe Today

Jeffrey Pierce and Peter Adams of Carnegie Mellon University in Pittsburgh, Pennsylvania, point out that cycles in numerous climate phenomena, including tropospheric and stratospheric temperatures, sea-surface temperatures, sea-level pressure, and low level cloud cover have been observed to correlate with the 11-year solar cycle.

However, variation in the Sun’s brightness alone isn’t enough to explain the effects and scientists have speculated for years that cosmic rays could fill the gap.
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To address the debate, Pierce and Adams ran computer simulations using cosmic-ray fluctuations common over the 11-year solar cycle.

“In our simulations, changes in [cloud condensation nuclei concentrations] from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties,” they write, “consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change.”

The results have met a mixed reception so far with other experts...