It's a bit long (1 hr and 15 min), but well worth the time. A few key points:
- The earth has warmed over the last 100 years. The change is about 1 degree F (or half a degree C).
- Over the many thousands of years where data are available, the earth has been much warmer (and much cooler) than it is today.
- The biggest determinant of earth's climate over those thousands of years is the effect of the sun. (Not surprising, really, since that's where almost all the heat comes from.)
- The second biggest effect is from the clouds.
- The main greenhouse gas is water vapor.
- Most of the CO2 in the atmosphere is not from human activities, Volcanoes, for example generate much more atmospheric CO2 than human activity, and eliminating all CO2 contributions from man would not even affect the amount of CO2 in a big way.
- Temperature and CO2 levels do track together over the very long term. However, the CO2 track is lagging the temperature changes by about 800 years. That indicates that, if there is a cause/effect relationship, temperature changes are causing CO2 changes rather than vice versa.
- Global restrictions on CO2 production would condemn the poorest people in the world to continued poverty and early deaths.
- Any dissent by climate scientists from the party line is met with threats, ad hominem attacks, and intimidation in order to maintain the fiction that no responsible person disagrees.
Since the download of the film takes awhile, I'd suggest downloading Google's standalone movie player for it (link on the page). The link was provided by anonymous commenter "Ted" in a comment on the previous post Saturday Night Warming.