Cosmic Rays and Climate Change
Dmitriev is not the only scientist who thinks this influx of cosmic rays has a major part to play in the recent increases in global temperature. Henrik Svensmark is the head of Center for Sun-Climate Research at the Danish Space Research Institute. In his book The Chilling Stars: A New Theory of Climate Change, he suggests that when cosmic radiation, especially protons, hit Earth's atmosphere, the reaction they cause has the effect of creating clouds. The more cosmic rays there are the greater the cloud cover.
A shutdown in solar activity and a decrease in the magnetic field of the sun leave our planet more open to the influx of plasmic energy from outside the solar system. This then leads to an increase in cloud cover and the kind of climate change we are now seeing. Svensmark predicts we could be about to enter a new Maunder minimum–like period and that global temperatures are about to rapidly cool.
Dr. Nir Shaviv, an astrophysicist, also thinks cosmic rays affect our planet's climate. By reconstructing the temperature on Earth over the past 500 million years, Shaviv thinks he has found that changes in the amount of cosmic rays are responsible for more than two-thirds of Earth's temperature changes, making it the most important driver of climate change over long periods of time.
Shaviv hypothesizes that the sun's passage through the spiral arms of the Milky Way appears to have been the cause behind the major Ice Ages over the past billion years. He has correlated variations in the cosmic-ray flux to the solar system's orbit around the center of the galaxy and through its spiral arms. In the more crowded spiral arms, like the Orion arm, which our Sun is currently in, there is a higher density of cosmic rays. Shaviv agrees with Svensmark that the result of this increase is that Earth becomes cooler.
Both Svensmark and Shaviv are considered climate skeptics who dispute the extent to which the creation of greenhouse gases is contributing to the current climate change. The year 2012 is significant in the context of research into cosmic rays because:
It coincides with the next predicted solar sunspot maximum, and recently discovered breaches in Earth's magnetosphere make us more vulnerable to solar-flare events.
The effects of increased cosmic dust and radiation entering the solar system will be likely to accelerate by 2012.
According to these scientists, whether the planet cools or heats up depends on the balance of solar activity and cosmic radiation.
The study of meteorites that have hit Earth during its passage through the arms of the Milky Way have shown up to 10 percent more cosmic-ray damage than those that sustained damage elsewhere. Shaviv believes that kind of cosmic-ray variation could alter global temperatures by as much as 15 percent. This would be sufficient to turn the Ice Ages on or off.
It is not necessary to agree with their views on climate change to share their conclusion that an increase of cosmic radiation may cause significant changes. Svensmark points out that it is actually well established and uncontroversial that solar activity has a direct influence on the eleven-year variation of stratospheric pressure levels found in the upper atmosphere. The electromagnetic fields of our planet are highly sensitive and respond to a range of influences from solar wind to tropical storms. A ten-fold increase in cosmic radiation is likely to affect these fields and the upper and lower atmosphere of the planet in ways that may be unpredictable. The debate is to what extent and how these changes will manifest.
