Watch CineCalidad. Concern over global climate change may be at an all-time high, but climate change is nothing new - the earth's climate always followed natural cycles of warming and cooling. In Unstoppable Solar Cycles, Dr. Willie Soon and Dr. David Legates challenge the popular idea that human-generated CO2, is causing catastrophic global warming. These scientists propose an alterantive theory - that the current warming has more to do with solar activity than with human activity.