The big news over the weekend has been the imminent publication of The Stern Report on the effects of climate change.
A lot of people are suggesting this report will herald a sea change in political and economic thinking on climate change. They may be correct because they have not taken into consideration the starting position of Stern's investigation. That position is that the IPCC is correct in it's assumptions (because that is all they are - assumptions; not evidence) that climate change is man-made AND avoidable.
Stern's conclusions may be correct IF the IPCC are correct - if they are not then Stern's report is so much more wasted paper. So is the IPCC correct in their assumptions.
Some facts and figures.
90% of the greenhouse effect is caused by water - 70% water vapour and 20% clouds.
Human activity accounts for around 3.4% of carbon dioxide emissions each year. The vast majority comes from natural sources. In other words - some 96% of annual carbon dioxide emissions come from non-human sources.
So, even assuming that CO2 accounts for the 10% of greenhouse effect that isn't caused by water vapour, less than 4% of that 10% is from human activities.
In other words, even if we cut our emissions in half (no chance) it's going to make absolutely no difference whatsoever.
The whole thing is based on a flawed proposition. In fact, the estimate of warming is actually less than the tolerance of our ability to measure temperature. In other words, the best guess at global temperature increase is smaller than the margin of error of measurement systems. It's like trying to accurately time the 100m sprint using a kitchen clock.
The massive over reaction to Stern's report is to be expected. The lack of scrutiny given to it's basis needs to be addressed.