Global warning is not something that you actually need an opinion on - the scientific data and consensus is quite well-established. The scientific consensus around climate change is actually stronger than the consensus around CFC's when the Montreal Protocol restricted them in 1989. If anyone is under the impression that there is a significant body of climatologists that hold a contrary view to the consensus, then I can direct you to the work of Naomi Oreskes (Professor of History and Science Studies, UC San Diego), who examined 928 abstracts featuring the words "global climate change" between 1993 and 2003. 75% explicitly or implicitly supported the consensus view, NONE dissented.

A small number of climatologists have published dissenting views - many have been rejected by peer-reviewed journals as being of insufficient quality. When you "follow the money" funding these studies, rather depressingly you all-too-often find people like the American Enterprise Institute (prominent scholars and fellows include such folk as Dick Cheney's wife, former Bush speechwriters, Newt Gingrich, funders include Exxon) and other (mainly) US (mainly) Republican-leaning organisations.

The simple truth is that global warming is unfortunately real. Some governments have responded to the challenges by attempting to take the pain of tackling climate change as soon as possible, arguing that THEIR companies and economies will reap the benefit of developing expertise (which they can sell to the US later) and the phasing-in the costs of climate change abatement and mitigation (rather than the pain of suddenly having to play catch-up). Other governments (notably the US and Australia) have adopted the view that by DELAYING the costs of abatement and mitigation, their economies will reap an advantage over the early-adopters. To follow this particular strategy requires a degree of political denial and foot-dragging (playing dumb with allies is possible, openly being mercenary is diplomatic suicide). The Republican position in the US is just politics, nothing more - there is no reason to think the actually BELIEVE their public position on climate change!

As humans we find the notion of changing our behaviour to be uncomfortable and challenging - and the changes we will make over the next hundred years to deal with climate change will be disruptive and frightening for many - and there will continue to be a small number of "scientific reports" dissenting from the consensus, there will be politicians, lazy journalists and others with their own agenda attempting to muddy the waters. History, I suspect, will not treat them kindly.