it's been a while, I know. But it's not as if I've been completely idle those past two months. Quite the contrary, I've closely followed the recent discussions about global warming. More specifically, whether global warming is man made or not. I've posted on several sites and spoke to a lot of people about it, so I guess it's about time to write something on my own blog.
About two months ago, Channel 4 in the UK broadcast the documentary "The great global warming swindle". As the title indicates, the program "revealed" that global warming happens, but is not caused by human actions. Rather, it claimed that the drivers are external factors such as sun activity and general ocean expansion.
The program brought forth those arguments via statements of a number of more or less reknown scientists, who took on very extreme positions around those aspects, thus supporting the "swindle" argument. Some of those scientists went so far as to say that the climate change models of a lot of other scientists are deliberatley tweaked to show that climate change is man made in order to obtain further grants for research into how to reduce it.
Only a week ago, I got hold of a Newsweek article with the title "Why so gloomy", which states essentially the same concept. It is written by Richard Lindzen, an MIT professor and well known opponent of man-made climate change. http://www.msnbc.msn.com/id/17997788/site/newsweek/
What the program (and the article) DID NOT say, was that for every scientist who claims global warming is driven by external factors, there are at least ten others who support the opposite view. Namely, that global warming is caused via a greenhouse effect of CO2 emissions, which in turn are produced in transport and industrial applications.
Another thing the program and article missed out in their line of argumentation, is that the solar activity cannot explain the (proven) temperature increase in the last 20-30 years. In fact, most of the theories stated have been reviewed and analysed over an over, only to be ultimately debunked. See http://www.monbiot.com/archive
I personally think that it is a real pity that this program was broadcast in this extreme form, i.e. showing only one side of the equation without giving any voice at all to the other one. This way, the vast majority of viewers (which might be in the low millions, considering the prime time schedule and the channel popularity, and that is not even counting the additional distribution through the audience itself) were left with the impression that they can go on polluting and consuming as before, with no need to change anything, since it makes no difference anyways.
The reality is that the link between human activity and global warming is not 100% proven. However, after several decades of research involving thousands of scientists and hundreds of universities and organizations, the general consensus is that it is highly likely (i.e., >90% probability), that global warming is caused by human activity. Main examples for those activities are personal transport (cars, planes) and general energy consumption (heating/cooling, industrial applications). See the recent summary report of the IPCC on this: http://www.ipcc.ch/SPM13apr07.pdf
What we should rather do is weigh the risks of both hypotheses against each other. It can't hurt if people leave their cars at home and take the bus to work, or if they buy energy efficient appliances. On the other hand, if we keep wasting resources like we've been doing for so long, and global warming gets out of hand (i.e., temperature increase of 2 deg celcius or more), then the effects would be catastrophic. See http://ecowhizz.com/sustainability/globalwarming.htm to get a taste.
If that happens, then finally everyone will know for certain what the true cause was. Only that then it will be too late.