The following was posted as a response to a recent article in the Chicago Tribune. I wasn't able to post it all so I reproduced it here. The Trib article is here.
The Trib article said, "But these days that thunderous 2007 verdict is sounding, well, a lot like tomorrow's weather forecast: It's very likely to be right. But there's some doubt."
Response: The IPCC report said the certainty was at the 90% level, so, yes, there's some doubt. But would you take 1 in 10 odds?
The article points out some minor problems resulting from the fact that the IPCC is composed of humans.
Response: Critical examination of the main body of evidence still holds. These minor problems do not change the overall weight of the evidence. Isn't it wiser to challenge the foundation of the main conclusion than worry about these insignificant problems?
My opinion: The lay person needs to rely on the scientists and disregard information coming from sources such as the Wall Street Journal or the Tribune. Those who are technical enough to understand the IPCC reports, should adopt the language of the reports to conduct sensible debate. The report discusses the various "climate drivers" that are in play. Those criticising the validity of the conclusions, should at least use the language the experts have used. The argument then becomes whether carbon dioxide is a significant "climate driver." There is no argument that carbon dioxide is increasing.
The information for the Intergovernmental Panel on Climate Change (IPCC) is found here:
Under the Publications and Data section there is a report section that contains the 2007 report. Each section of the report can be downloaded as a pdf file.
For those wishing summaries, I recommend the Union of Concerned Scientists' site which contains an FAQ:
I encourage informed debate. This is an important and complex issue. We need to have this debate without destructive name-calling and personal attacks. Our discussion should be focused on the following quote from the Union of Concerned Scientists' FAQ:
"The Intergovernmental Panel on Climate Change (IPCC) issued a global climate assessment in 2007 that compared the relative influence exerted by key heat-trapping gases, tiny particles known as aerosols, and land use change of human origin on our climate between 1750 and 2005. By measuring the abundance of heat-trapping gases in ice cores, the atmosphere, and other climate drivers along with models, the IPCC calculated the 'radiative forcing' (RF) of each 'climate driver' - in other words, the net increase (or decrease) in the amount of energy reaching Earth’s surface attributable to that climate driver. Positive RF values represent average surface warming and negative values represent average surface cooling. CO2 has the highest positive RF (see Figure 1) of all the human-influenced climate drivers compared by the IPCC. Other gases have more potent heat-trapping ability molecule per molecule than CO2 (e.g. methane), but are simply far less abundant in the atmosphere and being added more slowly."