There are very very powerful entities with vested interests in discrediting the well established evidence of climate change(cigs, cancer, and the tobacco institute anyone?).
Whether it's anthropogenic or not is besides the point, its important to err on the side of caution -- which means probable regulation -- something vested international conglomerates see as unprofitable/risky.
61 megs can be easily generated by a small staff interested in discrediting the conclusions of a debate which has long been over.
There's no coincidence about this at all, with cap and trade floating about washington. Just like the insurance lobbies with health reform, the worst polluters are pulling out all the stops to avoid being held responsible.