Sarah Palin is once again brushing off global warming as "junk science," comparing warnings about the threat of climate change to the eugenics movement of the early 20th century.

Last week, the former Alaska governor and 2008 Republican vice presidential candidate recorded a video for the Sarah Palin Channel dismissing the "con job" of man-made climate change.

"I'm not a denier. I don't doubt that climate change exists," Palin says in the video. "No one has proven that these changes are caused by anything done by human beings via greenhouse gases. There's no convincing scientific evidence for man-made climate change. The climate has always been changing."

She continues: "Climate change is to this century what eugenics was to the last century. It's hysteria and a lot of it's junk science. And when it's as discredited as eugenics, you know a lot of people are going to look very foolish and heartless."