One of my main problems with anthropogenic global warming (AGW) theories, as expounded by the United Nations Intergovernmental Panel on Climate Change (IPCC) and others, is that the increase in carbon dioxide in the ice-core record lags temperature by at least 800 years.
In other words, the long term record over 600,000 or so years, and numerous ice ages and interglacial warm periods, indicates that atmospheric levels of carbon dioxide have, until now, always increased after temperature.
from http://en.wikipedia.org/wiki/Image:Vostok-ice-core-petit.png
This point is disputed by neither AGW believer nor skeptics.
Given that historically, carbon dioxide does not appear to have been a driver of climate change, why would we expect it to be a driver now?
So, I was interested in the explanation in ‘The acquittal of carbon dioxide’ which is a rather long blog post by Jeffrey A. Glassman, PhD, that even includes an abstract:
“Throughout the past 420 millennia, comprising four interglacial periods, the Vostok record of atmospheric carbon dioxide concentration is imprinted with, and fully characterized by, the physics of the solubility of CO2 in water, along with the lag in the deep ocean circulation. Notwithstanding that carbon dioxide is a greenhouse gas, atmospheric carbon dioxide has neither caused nor amplified global temperature increases.
Increased carbon dioxide has been an effect of global warming, not a cause.
Technically, carbon dioxide is a lagging proxy for ocean temperatures. When global temperature, and along with it, ocean temperature rises, the physics of solubility causes atmospheric CO2 to increase. If increases in carbon dioxide, or any other greenhouse gas, could have in turn raised global temperatures, the positive feedback would have been catastrophic. While the conditions for such a catastrophe were present in the Vostok record from natural causes, the runaway event did not occur. Carbon dioxide does not accumulate in the atmosphere. [end of quote]
And what about this little illustration:
Jeffery Glassman describes it as:
“Several processes are simultaneously underway in the Carbon Dioxide Stream … Superimposed on a latitude–temperature graph is the solubility curve (shown without its ordinate axis). Solubility gets a shaded thickness to suggest the temperature dependent potential to absorb or release CO2 everywhere.
The atmosphere is a cloud to portray the global mixing of atmospheric gases by the winds.
The CO2 exchange should occur to some extent distributed over the surface of the ocean. It should also occur focused by the ocean’s meridional overturning circulation, also known as the thermohaline circulation, and popularly called a conveyor belt. The circulation descends at the poles and rises to touch the surface dominantly in the Indian Ocean and the Eastern Pacific. When the belt rises to the surface, the current is saturated with CO2 because of the rising temperature and falling pressure. It is ripe to release the gas. [end of quote]
Read the complete blog post here: http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.