I did not watch the Global Warming Swindle, but I saw the website, and there is some discussion about it. Stoat handles it here and here, realclimate has an article, and In The Green has a deconstruction.
But I think one point hasn’t been handled enough, although both Stoat and realclimate mention it: the apparent connection between solar activity and global warming. Channel4 shows a graph (see picture above). There are a few peculiarities which can be noted by just looking at the graph: it stops at 1980, thus omitting the dramatic rise since 1980, and there is no explanation what is meant by ‘solar’ on the right axis. It turns out that it is the Geissberg cycle. The data are apparently from a paper by Svensmark and Christensen. A paper by Damon and Laut has analyzed those data, and leaves no prisoners:
However, close analysis of the central graphs
in all of these articles reveals questionable
handling of the underlying physical data.
In the 1991 article, the impressive agreement
of the solar curve with terrestrial temperatures
during the global warming of the recent decennia
had been a major factor in the article’s strong
impact. But this agreement was actually an
artifact: it had simply been obtained by adding, to a heavily smoothed (“filtered”) curve, four
additional points covering the period of global
warming, which were only partially filtered or not filtered at all.
But not only that. There are much more data available. Damon and Laut show another figure, showing temperature and Geissberg data from 1700 to 2000 (red line shows smoothed Geissberg data, green and blue the temperature):
There is not so much correlation any more. If there were, we would have had warming events like today around 1850 and 1760. Damon and Laut remark:
If Friis-Christensen and Lassen  had been correct, there should have been 11 global warming events during that time [ in the last 12,000 years ] equivalent to the contemporaneous event. However, the current event is unique and obviously of anthropogenic origin.
I suggest to read the whole paper.