The Sun

more likely causes "global warming" than humans in my opinion. I'm glad at least a few people agree.

Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a natural—and not a human- induced—cause, according to one scientist's controversial theory.

Abdussamatov believes that changes in the sun's heat output can account for almost all the climate changes we see on both planets.

Mars and Earth, for instance, have experienced periodic ice ages throughout their histories.