Paul Thornton, letters editor, writes that the policy is not new - it just caught the attention of, well, the climate change deniers, and they aren't happy. The policy, "(letters) that say there's no sign humans have caused climate change do not get printed" was cited in a "letters postscript" on Obamacare.
Thornton writes to clarify that the "no letters from climate change deniers" policy was his, as Noel Sheppard at NewsBusters ("the leader in documenting, exposing and neutralizing liberal media bias") had ascribed that policy to the wrong Los Angeles Times editorial writer in his blog that blasted the policy.
Thornton clarifies the Times policy on printing letters from climate change deniers and the reason for it.
As for letters on climate change, we do get plenty from those who deny global warming. And to say they "deny" it might be an understatement: Many say climate change is a hoax, a scheme by liberals to curtail personal freedom.
Thornton explains that he relies on the experts, citing "the Intergovernmental Panel on Climate Change -- a body made up of the world's top climate scientists -- said it was 95% certain that we fossil-fuel-burning humans are driving global warming. The debate right now isn't whether this evidence exists (clearly, it does) but what this evidence means for us."
Finally, Thornton distinguishes opinions from falsehoods in the letters he selects for publication in his paper.
Simply put, I do my best to keep errors of fact off the letters page; when one does run, a correction is published. Saying "there's no sign humans have caused climate change" is not stating an opinion, it's asserting a factual inaccuracy.