Friday, January 18, 2008

It's Water Vapour, Stupid

One of my intuitive objections to the theory of global warming has been the role of carbon dioxide as a trigger mechanism, the driver of changes in the earth's atmosphere. Yes I recognize that levels of carbon dioxide have risen from around 260 ppm to 360 ppm, but I still can't grasp how a gas that represents less than 0.04% of the atmosphere dictates the climate for the whole planet. To my mind, the world is a very complex, dynamic and deeply inter-related system: very robust, very adaptable and very resistant -- certainly, a geological time scale of several hundred million years would seem to both suggest and support this contention.

So why would a trace gas be so crucial? And when did carbon dioxide go from irrelevant to the dominant driver of climate? (For example: past geological records indicate carbon dioxide levels in excess of 7,000 ppm and no correlation with temperature; Gore's famous graph where carbon dioxide lags behind temperature changes by 800 years; and, the more recent disconnects of carbon dioxide levels from temperature changes throughout the past century).

So it was with great interest that I read this post and the associated article on the coupling of water and carbon fluxes via the terrestrial biosphere. This work suggests that the larger water cycle controls the much smaller carbon cycle and not vice versa.

Well duh! Doesn't this seem like common sense? Which is why I personally think so many have heard the global warming rhetoric and are content to accept that human's play a role in modifying the weather but balk at the wider implications of planetary Armageddon as just outside their accepted realm of common sense comprehension. Environmentalists can bitch and whine all they want as long as their views only marginally impinge on real life -- but the lay public is not about to jump off a cliff just because a few loons say it would be a good idea.

It will be very interesting in the coming months how this particular research is treated both within the blogosphere, the mainstream media and within the scientific community itself. Does it get reported, acknowledged and integrated into our increasing knowledge pool? Or, does it get ignored, castigated and otherwise explained away because it threatens the supposed hegemony of the global warming paradigm of science?