Anything that remotely implies scientific studies have miscalculated factors in global climate change is fodder for those who oppose the notion of global warming. So when a respected scientist, Dr. Wolfgang Knorr from the University of Bristol publishes a paper with results that indicate the level of carbon dioxide in the atmosphere has remained virtually constant – despite the large increase in worldwide carbon dioxide output; it’s likely to produce controversy.
However, the Knorr study is not about challenging the overall global warming hypothesis, or even attacking particular models. In most ways, it’s the normal process of science adjusting and correcting its hypotheses. Here’s some of the announcement:
The results run contrary to a significant body of recent research which expects that the capacity of terrestrial ecosystems and the oceans to absorb CO2 should start to diminish as CO2 emissions increase, letting greenhouse gas levels skyrocket. Dr Wolfgang Knorr at the University of Bristol found that in fact the trend in the airborne fraction since 1850 has only been 0.7 ± 1.4% per decade, which is essentially zero.
The strength of the new study, published online in Geophysical Research Letters, is that it rests solely on measurements and statistical data, including historical records extracted from Antarctic ice, and does not rely on computations with complex climate models.
So is this good news for climate negotiations in Copenhagen? “Not necessarily”, says Knorr. “Like all studies of this kind, there are uncertainties in the data, so rather than relying on Nature to provide a free service, soaking up our waste carbon, we need to ascertain why the proportion being absorbed has not changed”.
[Source: University of Bristol]
What the Knorr study suggests is that factoring the so-called ‘carbon-free sink’ into global climate models should be re-evaluated, and probably more weight given to the ability of the earth and oceans to absorb carbon dioxide. However, Dr. Knorr himself added (elsewhere) that “The amount of greenhouse gases in the atmosphere is still increasing, even though half is absorbed by the Earth. Also there are fears that the oceans and soil will become saturated and are unable to absorb any more carbon dioxide in the future.”
It should also be added that absorption of carbon dioxide by the oceans has a penalty – it forms carbonic acid, and the ocean becomes increasingly acidic, which has vast implications for life in the oceans. The loss of coral reefs is already blamed on the rising level of acidity.
From a PR perspective, all global warming models and their underlying hypotheses are vulnerable. The details are almost certain to change. From time to time, important assumptions may be challenged and fall away. This is normal science, especially for a topic so complex and massive, but in the current hot-house environment (pun intended), challenge and change is immediately interpreted not only as weakness but as failure.