- View here: (no longer available -- Please let me know where it is.)
This is a video that presents the opposite theory, that climate change is not due to anything but natural sun variation. Very interesting, but please take this with a grain of salt.
I watched it two times. Please read about the producer of this film: http://en.wikipedia.org/wiki/Martin_Durkin_(television_director
and about the film itself http://en.wikipedia.org/wiki/The_Great_Global_Warming_Swindle
It appears that Durkin has constructed an interesting presentation that is certainly filled with half-truths and all out lies. For example, the Medieval Warm Period is stated as being a time even warmer than today. In fact this is apparently not supported by any data I've seen. See this:
You will note that the chart clearly shows 2004 above the MWP. In the film (at location 8:21) the chart does not match. "NOW" on Durkin's chart is not really close to the current data. Reviewers complained about this presentation as Durkin did not include the last few years of the century, and not until 2004. His chart makes it look like the temperature is stabilizing.
On the other hand, the film does accurately state that this partially coincides with the Medieval Maximum solar activity. I note that in the review of the film, Durkin listed some people interviewed as climate scientists who were not.
You should read this page: http://en.wikipedia.org/wiki/Scientists_opposing_the_mainstream_scientific_assessment_of_global_warming
I note this statement by Richard Lindzen, MIT:
"Indeed, if all else were kept equal, the increase in CO2 should have led to somewhat more warming than has been observed."
Here's a scientist who used to be critical of Global warming but is now a believer, but he gives Gore only lukewarm approval. http://en.wikipedia.org/wiki/Ronald_Bailey
Regarding solar variation, see: http://en.wikipedia.org/wiki/Solar_variation
A 2006 study and review of existing literature, published in Nature, determined that there has been no net increase in solar brightness since the mid 1970s, and that changes in solar output within the past 400 years are unlikely to have played a major part in global warming. http://www.terradaily.com/reports/Changes_In_Solar_Brightness_Too_Weak_To_Explain_Global_Warming_999.html
Data collected from radiometers on U. S. and European spacecraft show that the Sun is about 0.07 percent brighter in years of peak sunspot activity, such as around 2000, than when spots are rare (as they are now, at the low end of the 11-year solar cycle). Variations of this magnitude are too small to have contributed appreciably to the accelerated global warming observed since the mid-1970s, according to the study, and there is no sign of a net increase in brightness over the period.
There is a section on Global warming on that page you should read. Sunspots don't seem to be the driving force. Look at this: Error: not an image at 'http://en.wikipedia.org/wiki/Image:Temp-sunspot-co2.svg'
This paragraph is interesting:
Although correlations often can be found, the mechanism behind these correlations is a matter of speculation. Many of these speculative accounts have fared badly over time, and in a paper "Solar activity and terrestrial climate: an analysis of some purported correlations" (J. Atmos. and Solar-Terr. Phy., 2003 p801–812) Peter Laut demonstrates problems with some of the most popular, notably those by Svensmark and by Lassen (below). Damon and Laut report in Eos that the apparent strong correlations displayed on these graphs have been obtained by incorrect handling of the physical data. The graphs are still widely referred to in the literature, and their misleading character has not yet been generally recognized.
My view is that there is no doubt that Global Warming exists, and apparently you agree with this assertion. Secondly, it seems there is still some scientific controversy, but the video you recommended is a slanted view with an attempt to prove the opposing by taking selective information, and twisting them as well. I found it an interesting film to watch as there is no doubt there are other theories. He did not address the serious changes to the ice shelf in Antarctica that is more than "seasonal" ice falling into the ocean. Film clips in the video were sometimes decades-old, and some of those interviewed objected to the way he used their interview. The idea that our current temperature is less than the Medieval maximum is crucial to his arguments that "the polar bear got through it before" etc. but it seems that is not true. Current temperatures are higher.
-- Raymond Lutz
- 11 Jul 2007