But changes in solar radiation cannot explain what has happened in the past half century.

Not until late January does the increase in solar radiation finally become strong enough to compensate for the heat being lost to space.

At least they wouldn't fry in radiation that no one had seen from afar.

He was originally an economist before getting interested in radiation.

At the top of the list is an increase in ultraviolet radiation.

"Because of my background, I was interested in radiation," she said.

Scientists say the increase in solar radiation poses no increased health risk to people or other life on Earth.

Such facts underlie big changes in total estimated radiation over time.

Over the course of a year, the most obvious pattern is seasonal changes in net radiation.

The story really begins many thousands of years ago when a sudden change in solar radiation raised the temperature here on Earth.