I appreciate that like me, you reply to Grendel's idiotic propaganda cut and pastes, for the benefit of any who may not be familiar with the extent of deceit that emanates from Denialist campaigners, and never expect Grendel to ever admit to any error ever, or to ever acknowledge that lies he has posted have been exposed as lies many times over, for he continues to cut and paste the same old debunked garbage ad nauseum.
He chooses places like Heartland Institute, a extreme right wing bastion of idiocy that will run professional disinformation campaigns for your cause, for a price, as his sources for the cut and paste sprees he is most famous for.
Unfortunately with the demise of One Nation, he needed a new obsession, and lucky old us (sarc), he chose Denialism.
Just bear in mind, two rules Grendel assiduously follows, always ignore any, and all evidence that comes from actual scientists who specialise in the field, and who have submitted their work for peer review so that their conclusions can be checked and tested, and secondly;
Only ever believe what you read in Denialist blogs, because anonymous PR guys and ultra right wing extremists are the only people he trusts.
So in conclusion, we all know there is not a snowballs chance

of Grendel ever honestly appraising the actual evidence available, and when he does more than cut and paste the professional lies from the denial sites we see him show his true colours. So much of the professionally contrived PR man bull he just pastes, can seem credible if you are unfamiliar with the real truth about the things they deliberately misrepresent, but do not buy it, such lies should never be left unchallenged.
Muso's wiki provides great information for any who are honestly seeking some clarification, and want to better educate themselves to be able to understand this issue better, plus it provides many links to actual studies and data which corroborate the facts he provides.
If you just want an easy primer to explain the common denialist lies, you can go to,
http://www.realclimate.org/index.php/archives/2004/12/index/#Responseswhich will show the scientific debunking of the lies Denialists put forward as alternative theories, plus you can also look up the opinions and credentials of the real scientists, as well as the Denialist scientists, and then make up your own mind who to believe.
So do not believe me, do not believe Grendel, go to the experts, and see if you believe them, I know I certainly do.
Whatever you do, never, ever accept any denialist argument without checking it out first at a reputable place where real scientists provide real answers, and then decide for yourself.