Climate Change--The Debate Continues

Climate Change is a fascinating topic--especially given that the climate has never been unchanging. You might call the term "climate change" somewhat redundant. Modern "Climate Change" is known more accurately as "catastrophic anthropogenic global warming (CAGW)," and it revolves around the concept of the trend change in the "global average surface temperature." But just a bit of reflection should reveal to most that there is no such thing as global average surface temperature--at least no such thing that can be measured. It is a fictional abstraction, a construct-of-convenience, used to simplify a complex system for public consumption and other less reputable ends.

Roger Pielke Sr., climatology professor at the Colorado State University, discusses this issue and a few other equally fascinating and controversial issues in this recent posting on his website:

The global average surface temperature trend is an icon of the climate change community (e.g. see). Global policies are based on this temperature.

The basic concept is that if the radiative forcing of the climate system is increased, the surface temperature will warm until the outgoing long wave radiation becomes in balance with the new radiative forcing. There is a lag between when the radiative forcing is imposed and when an equilibrium is achieved with the new forcing (this has been referred to as a temperature increase which is still in the “pipeline”). If the forcing changes over time, the surface temperature will not, of course, ever reach an equilibrium.

This lag is one of the reasons that we have recommended ocean heat content changes as a more appropriate climate metric for global warming and cooling, as there are no lags involved; just an accounting for the Joules of heat in the climate system, as discussed in

Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335.

Moreover, an average global temperature can only be diagnosed; it cannot be directly measured. The approach has been to sample air temperatures across the globe in order to construct a global average surface temperature trend. However, there is a major problem with the use of the sampling of surface air temperature trends as is discussed below, for example, for nighttime minimum temperatures over land (which are used as part of the construction of the global average trend).

In our submitted paper

Pielke Sr., R.A., C. Davey, D. Niyogi, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, J. Angel, R. Mahmood, S. Foster, J. Steinweg-Woods, R. Boyles , S. Fall, R.T. McNider, and P. Blanken, 2006: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Research, submitted, we discuss this climate metric.

Source.

Pielke supplies links to some fascinating background reading, for the interested.

For the past fifteen years or so, climate science has been heavily influenced by political forces, which have had a biasing influence toward the more sensationalist climate model results.

While most climatologists agree that human activity is certainly influencing global climate, there is a significant debate about specifics--and the devil is in the details. People with superficial acquaintance with media reports about climate change have been well exposed to the sensationalist, catastrophic point of view. "Do something, even if it's wrong, dagnabbit!"

It may take some time, but the current dominance of the debate by the sensationalists will only last for a relatively short while longer.