Saturday, November 7, 2009

Global Warming: How much do we really know?

It seems these days that everyone has bought into the idea of “global warming. Congress is busy debating a ‘cap & trade” bill and the “Kyoto Protocol” has become the international standard for dealing with greenhouse gasses. Environmentalists are predicting the end of life on the planet, if we do not do anything about it.

So, perhaps the lone voice in the darkness should ask the question “Is it true?”

There is a lot of “hype” over CO2 content in the atmosphere and its effect on the planet’s temperature. Scientists are talking it up in hyperbolic terms because it draws more attention to them and more research dollars to their projects. If global warming was not a concern, they would be relegated to jobs as weathermen. They seize on anecdotal evidence to support their assertions (this is advocacy, not science).

It is important to separate fact from fiction and what we know from what we do not know. To help with this, let me make some observations. First, examine this chart. The chart traces the history of the earth’s temperature for the last 500 thousand years, along with the concentration of atmospheric CO2 and dust. It should be read left to right: the left side being the current day and time-past being to the right. The current day temperature variation is “zero” and historical variations are plotted backward from that point.

It is clear that there is a causal relationship between atmospheric CO2 gas composition and the temperature of the earth. While scientists jump to the conclusion that CO2, a “greenhouse gas” causes the temperature to rise, when we examine the chart closely, we see that the earth’s temperature appears to rise in advance of CO2 content in the atmosphere. That should raise a question: Why? Could there be a more powerful force in the planet’s eco system? Which is the “cause” and which is the “effect”? Another big question that arises once we look at the history of the planet’s temperature and CO2 content is “Since these cycles have occurred before human’s had cars, before the industrial revolution, what causes the temperature and CO2 gas content to rise and fall?”

It is clearly the case that the planet is warmer today than it generally has been. It is also true that the planet’s temperature has peaked at about the present level many times in history…then declined. Once again, that has happened hundreds of thousand years before humans contributed to its “carbon footprint”.

One can make a case for any conclusion that they want by simply selecting the timeframe for the data. During the last 10-12 years, the temperature of the earth has cooled; during the last hundred years the temperature of the earth has warmed; during the last 5,000 years the earth has cooled; during the last 20,000 years the earth has warmed.

Scientists (with a stake in the race) argue that the polar ice cap is receding. This is true, but only for the northern hemisphere; the southern ice cap is growing. They argue that industrialization over the last 150 years has caused the temperature of the planet to warm. At the same time the temperature of Mars has also warmed by about the same (percentage) amount. But there obviously are no people on Mars. Could it be that some more powerful exogenous force has caused it: perhaps flair-ups on the sun?

An important principle to understand is that scientists, activists and political leaders can make any case they want by presenting selected data that supports their advocacy, and leaving out data that refutes it.

Research in this area is important, but it must be done with an objective mind. The drivers for global warming and cooling are very complex and dynamic. Our planet’s eco system is very complex and changing. The study of this needs to be an interdisciplinary pursuit. Atmospheric sciences must consider the interaction of the atmosphere with the ocean (it absorbs about 50% of the CO2) and the interaction with the earth’s surface and its biomaterials (plants, biomass decomposition, etc.) as these are as big a factor (and perhaps overwhelmingly dominant) as the effect of humans and animals.

If these forces are as profoundly causal as they have been in the past, the planet earth may have past the warming peak…and we should worry more about the return of a cooling cycle and another ice age. Mankind may be simply a passenger on the train of the swings warm and cool of our eco system. What we do, or don’t do, may have little effect. We actually know very little about these processes, but we should push on to understand them.

But one thing is sure, these temperature changes are more glacial than the polar ice flows themselves and significant changes will take thousands of years.

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