Clouds, Climate and Cosmic Rays
News story originally written on September 4, 2002
It is well known that our planet is becoming a warmer place right now. However, what scientists find really strange is that higher levels in the atmosphere stay cool while the Earth's surface warms.
Clouds are probably responsible for this trend. "A systematic change in global cloud cover will change the atmospheric heating profile," said Fangqun Yu, author of a new study. High clouds reflect sunlight and low clouds retain surface energy, so, increases in amounts of thick, low clouds can warm the surface of the Earth, but not higher levels in the atmosphere.
How could the worldwide cloud cover change? Cosmic rays may be to blame for changes in the patterns of cloudiness, warming Earth's surface by generating a blanket of low, thick clouds. More cosmic rays, increases the number of low clouds that warm the surface.
Additionally, greenhouse gases boost the impact of cosmic rays. This means that as our pollution sends more greenhouse gases into the atmosphere, cosmic rays are able to create even more low clouds.