Recently I was informed about two notes about the climate change issue. One note originated from Dr. William Grey, Prof. Emeritus, Colorado University, USA and the other by Dr. Roy Spenser, EOS, University of Alabama, USA. These notes are very interesting studies.
While Prof. Grey points out that the global warming trends as elucidated in IPCC reports are all based on data sets which are dominated largely by observations over urban regions in northern hemisphere, the large warming signal obviously can not be attributed to CO2 warming alone. If this fact be considered as a biasing term in the analysis, it would mean that the residual warming (which may be smaller in magnitude) can not be separated from the “so called” greenhouse warming and the earth’s natural cooling-warming cycles (where ocean thermohaline circulation play major role).
The deposition of Dr. Roy Spenser to the house committee on Oversight and government reform in US (2007) is an interesting statement about the manipulations of the scientific evidence for political purpose. Notwithstanding the political interpretations, which some times might be required to safeguard the interest of any nation, the deposition includes some statements which are worth while from scientific angle. The climate change data still does not resolve the issue of cause and the effect. In the early stages (like Holocene period), CO2 was available abundantly, probably, due to large scale upwelling in ocean (specifically North Pacific and Indian Ocean). The warming of northern hemisphere was punctuated by strong thermohaline circulation in the ocean. The release of energy by this deep sea circulation to the upper ocean brought about increase in evaporation/ precipitation at the ocean surface. This inturn facilitated the precipitation and therefore, the question is: Is it possible that the precipitation (releasing lots of latent heat to the atmosphere) really holds the key for temperature warming on this planet?. Under this scenario, it would seem that the post industrial era would have released CO2 but its contribution to the global warming would have been more of a feedback process (like the one assumed for water vapour) than a real cause for start of warming trend.
In other words, the real cause could be a natural cycle of the planet where precipitation and thermohaline circulation play a role (ice-age cycles of the planet). The large error margins in carbon budgeting of ocean further compound the identification of greenhouse gases as the cause. Would it mean that the interpretations of the results from global climate models are skewed (or unfairly manipulated). Or is it that we, the scientists do not want to admit very openly the inadequacies in our understanding of the processes? Who are we afraid of? Roy raises a very pertinent issue. Are we getting into the trap of sponsored research, a la, pharmaceutical industry?
I consider both these notes very interesting and pertinent because these re-enforce my views that more concerted work need to be directed towards understanding hydrological process (both atmosphere and land). As far as the input to the policy makers is concerned, let that be a calculated risk on the basis of national agenda for the time being. Why impose a bogey of “consulted support” from scientific analysis?
I will refrain from making any accusation on the “unfair practice” by us scientists for not completely overhauling models adequately. I know the mammoth work involved. Still, I am very optimistic that some day, when realization sets in, the problem will be set right. Let us say Amen to that...... Vijay