Putting Global Warming on Ice

What makes the earth's temperature rise and fall? Do greenhouse gases block solar heat from leaving the earth, or is it only a product of solar activity? Many people have theorized on what causes temperatures to change. A catch phrase named Global Warming came to popularity. Environmentalists from all walks of life joined the 'global warming' fight. According to Thomas O'Connell the global warming debate wasn't accepted in the 60's and 70's when he studied it. It only became popular recently in the 90's. …