The documentary had plenty of big names, and much name-dropping of institutions and awards. The content, however, was riddled with old half-truths and some straw man arguments thrown in for good measure. The main content is summarized below, and annotated with comment and links for better info. I would be happy to discuss any of my comments here - feel free to make corrections, improvements, additions below.
1. Climate is always changing, this temperature is not strange. We shouldn't worry, as warming will bring "vineyards ... [a] wonderfully rich time." (Philip Scott) Climatologists have never denied that temperature variation has been a part of the Earth's history. What is worrying, however, is that the levels of CO2 are higher than they have been for 650,000 years (link) and likely in 20 million years (link), and the rate that current changes are taking place (see here and here) are much faster than they have been in the past. And while we may have vineyards and a wonderful time here in the UK, the developing countries will certainly get the short end of the stick.
2. Historically, CO2 trends appears to lag global mean temperature increases; CO2 doesn't drive temperature change. Yet another old argument. Oddly, they laugh at Al Gore's comment that the relationship between CO2 and temperature change is "complicated", suggesting he was glossing over the details and hid the truth. (If the carbon cycle isn't complicated, I don't know what is!) They then proceed to give an overly simplistic view of the climate, stating that during the heaviest industrialisation post-WWI, there was global cooling - therefore CO2 had no effect. They fatally neglect the time lag for warming from CO2, or the cooling impact from aerosols like SO2. But Real Climate to debunk their claim here: the apparent lag of CO2 from temperature in the historical records is a result of feedbacks which release more CO2.
3. Human's can't change the atmosphere - it's so immense. [Update 15.03.07: Having read the transcript, I see that misheard Stott's comment. He indicated the Sun was so immense, suggesting we were just small fry with no impact. I think my comment still holds, however.] Logical fallacy here - appealing to emotion and wonder. For a really accessible example of humans impacting the climate, we just have to look at the impact that the lack of airplane contrails had on temperature in the US after 9/11 (link).
4. Humans contribute only a minor part of total CO2. This is also not disputed. However, we do know that CO2 is a greenhouse gas, and that humans have contributed to recent increases in CO2 concentrations (link, link). It appears, that by disrupting the natural balance of the carbon cycle (which involves the atmosphere, plants, animals, oceans, and geology), we are able to warm the planet.
5. The surface of the Earth is warming faster than the troposphere, which is the opposite of what greenhouse warming theory would suggest. This argument has been going on for years. However, a 2004 article in Nature (link, and more discussion here) puts rest to these concerns, and the IPCC Fourth Assessment report will conclude that the troposphere is warming at least as quickly as the surface - consistent with theory. The confusion of whether the troposphere was warming quickly enough arose from a cooling bias from the stratosphere (which cooled as a result of less ozone). [Update 15.03.07: See also a US CCSP report which Christy himself co-authored here. It said: "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human induced global warming. ... This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected."]
7. Cosmic rays can explain warming, as they affect cloud cover - which has a cooling affect. The argument from Nigel Calder and Danish space science skeptics has been seen before, and on BBC's Newsnight - where Calder was thoroughly demolished by an atmospheric physicist from Imperial College. Basically, the Danes have found that cosmic rays produced ionized particles, an published it in a peer reviewed paper here. The article made no mention of global warming or climate change, but Calder and the Danes wrote a book anyway, making numerous jumps of assumption to say that those ionized particles would produce more clouds and thus cool the Earth. However, those assumptions have not been peer-reviewed, and there exists no long-term trend for cosmic ray flux, while global mean temperature keeps rising. RealClimate has discussed his claim (here). More arguments for cosmic rays came from Nir Shaviv et al. These have also been questioned in peer-reviewed literature here and discussed in RealClimate.org here.
6. Media and scientific self-interest in reporting more and more dramatic results. The global warming community needs to perpetuate itself to keep the money flowing. This, however, is not an argument against the science, but a clever tactic by the documentary makers to get the audience thinking that it is all a big conspiracy. Yet they fail to mention that hysteria is not new to the media - see crime, pedophilia, and immigrants as other examples. As for self-interest in science, it is of course in anyone's interest to promote the importance of their work - for publicity or money. However, the documentary makers failed to show how this debunked the theory of global warming.
8. Environmentalists say industrialisation causes global warming, and thus want to stop industrialisation and the great improvments it has given our lives. A straw man argument if I've ever seen one. By associating CO2 emissions with industrialisation and economic growth, the documentary plays an emotional trick by making us think that the quality of life we have will be taken away from us if the environmentalists had their way. While CO2 emissions are indeed associated with industrialisation, it is not a relationship that cannot be undone. For example, Vestas in Denmark have generated immense wealth by producing wind power generators. China has recently decoupled economic growth from greenhouse gas emissions growth (link) [Update 15.03.07: Better info in this and this article. Thanks, Bruce, for the comment.].
9. "Developing countries are coming under intense pressure not to develop." They finally claimed that environmentalists are stopping developing countries from installing fossil fuel plants, forcing them instead to use expensive renewable source of energy instead. This was called "anti-human". Unfortunately, no evidence was presented on this point - no data on World Bank projects, or similar. They did, however, visit a hospital that had been fitted with a solar panel, which could power either the fridge or the lights - but not both. The inference was that if environmentalists hadn't stopped the building of a fossil fuel power stations, the hospital could use the fridge and lights at the same time. Yet did the documentary prove that the hospital was in proximity to be wired to the grid at lower cost than the panel? You bet they didn't!
