Maybe he just reads the scientific data….
Check it out:

Liberal media outlets are already warning Democrats not to trust Republican presidential contender Rand Paul on global warming, saying he’s just another “denier” when it comes to claims that human activities are warming the Earth.

Ben Adler at progressive magazine Mother Jones notes that “a couple of recent media reports assert, on the thinnest reeds of evidence, that Paul has accepted climate science or endorsed regulating carbon pollution.” Adler then exclaims, “He hasn’t. Sorry, reporters: There is no counterintuitive story about Paul and climate change.”