tom writes:

"Hey Mark check out petitionproject.org. These 33000 scientists are skeptics"

--

Well, they claim they're scientists.

Note that there's no mention of a criterion for determining if the signees actually have the qualifications they claim.

And of the 31,487 signees, a grand total of 39 are (allegedly) climatologists.

Note also that "a piracy alert has been triggered over this website"

This kind of failure to consider only hard evidence is why Deniers aren't taken seriously by anyone but themselves.