The anonymous BBC “reporter” who wrote an article “No let up in greenhouse gas rise” either does not understand the subject or is dishonest.
The article claims that carbon dioxide is “the major contributor to climate change”. It is a lie not claimed by any scientist, but of course most people think this.
That is because they have been told that human generation of CO2 is causing a catastrophic rise in temperatures. What they have not been told is that this claim is based on an assumption of positive feedback, not only that but feedback that must have greater influence than the CO2. Heat trapping by CO2 just isn’t enough to support the claims of the warmists, and they randomly add large positive feedback to models. So even according to climate hysterics the carbon dioxide itself is not the major contributor, the putative feedback mechanism is.
This is not a trivial falsehood. How many times have we read that this is “basic physics”, and that “carbon dioxide is a greenhouse gas” so must be causing the rise in average temperatures? How rarely do the people who tell us this admit that without positive feedback CO2 cannot explain most of the warming since the 1970s? How many state that all the nightmare scenarios claimed in the press require a lot of feedback?
Feedback is very important to a lot of what I have studied and taught. It comes into a lot of physics, into geology and in aviation theory in the principles of flight (stability of an aircraft is determined entirely by feedback). What I can say is that positive feedback is that it is rare in natural systems and essentially unheard of in a stable system [correction: essentially unheard of in a non-linear system which shows long-term stability]. Positive feedback is the cause of instability.
Which thought brings us to an interesting place. Either the temperature has positive feedback, and is likely to be unstable, or else temperature is stable and shows little or negative feedback. The whole climate panic is based on the assumption that the temperature is stable (and so the recent fluctuations are unusual) but that temperature response to carbon dioxide shows positive feedback …
Update: thanks to an anonymous commenter for a useful correction. The comments now contain a brief discussion on stability.