The solar eruptions are known to shield Earth's atmosphere from cosmic rays. However the new study, published in , shows that the global cloud cover is simultaneously reduced, supporting the idea that cosmic rays are important for cloud formation. The eruptions cause a reduction in cloud fraction of about 2 percent corresponding to roughly a billion tonnes of liquid water disappearing from the atmosphere.
As Dr. Roy Spencer notes,
"The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling."The IPCC models fail to consider multiple solar amplification mechanisms, including cosmic rays and numerous other amplification mechanisms, thereby ignoring that solar activity can explain the 0.7C global warming since the end of the Little Ice Age in 1850. Solar activity reached a grand maximum in the latter half of the 20th century, and accumulated solar energy (the 'sunspot integral') explains global temperature change since 1900 with greater than 97% statistical significance. This new paper confirms that solar activity variation can account for a 2% variation in global cloud cover, sufficient to explain the warming of the 20th century and without any consideration of CO2 "radiative forcing."
A team of scientists from the National Space Institute at the Technical University of Denmark (DTU Space) and the Racah Institute of Physics at the Hebrew University of Jerusalem has linked large solar eruptions to changes in Earth's cloud cover in a study based on over 25 years of satellite observations.