Peter Adams, a professor of civil and environmental engineering from Carnegie Mellon University and Jeff Pierce from Dalhousie University in Canada recently tested a controversial hypothesis that says changes in the sun are causing global warming.
The pair of scientists developed a model to perform the test, according to the Carnegie Mellon press release.
Hypothesis: Increased solar activity reduces cloudiness by changing cosmic rays. So, when clouds decrease, more sunlight is let in, causing the earth to warm.
The findings: The first atmospheric simulations of changes in atmospheric ions and particle formation resulting from variations in the sun and cosmic rays showed that changes in the concentration of particles that affect clouds are 100 times too small to affect the climate.
"The basic problem with the hypothesis is that solar variations probably change new particle formation rates by less than 30 percent in the atmosphere. Also, these particles are extremely small and need to grow before they can affect clouds. Most do not survive to do so," Adams said in the press release.