Thursday, 3 September 2009

Climate change Thursday #6

Beware the wise. GUEST POST from Professor Adam Foster

Climate change is one of those topics that drags an opinion even from those people who proudly exclaim their ignorance of science. For egregious examples of this please see http://bit.ly/13ewI and http://bit.ly/W2oe8 (see what a liberal editor I am! AP.) It has transcended real knowledge, and become accepted wisdom of the masses.

In 2004 I was sitting in a hotel bar in Athens with a colleague watching the devastation following the Indian Ocean earthquake. As the death toll climbed through 100,000, a lady on a table in front us turned round and said with great sincerity, “Global warming”.

I watched with great amusement as my colleague, a researcher in climate modelling, fought internally with the desperate need to explain that it had absolutely nothing to do with global warming, knowing that it would achieve little save animosity. She eventually replied, “Yes. A tragedy.”

However, opinions on climate change without knowledge are usually easily dismissed, as in any field. Much more dangerous are opinions backed by a little knowledge, as these require expert analysis, which is not easily accessible. A classic example is given by this well-meaning gentleman (His full comments are below this New Scientist blog):
"Analysis.

Considering the above data table, we can see that the specific heat of CO2 is greater than any of the 3 major atmospheric gases: CO2 at 36.94 J/mol ( -1 ) ( K ) Nitrogen at 29.12 J/mol ( -1 ), Oxygen at 29.38 J/mol ( -1 ) and Argon at 20.77 J/mol ( -1 ) .

Now, taking the assumption that burning fossil fuels will remove 100 ppm of oxygen from the atmosphere by combustion and replace that O2 with CO2, given that CO2 has a specific heat at 36.94 and O2 at 29.38 the heat capacity of that 100 ppm of the air would increase by about 25 percent.

As 100 ppm is 1/10,000 of the atmosphere, that would be an change in the thermal properties of the air of 1/4 of 1/10,000, or 1/40,000 increase.

If the heat gradient of the Earths atmosphere is 400 degrees F, that is to say, if the surface temperatures on Earth would decrease 400 degrees F without the existence of the atmosphere, which is similar to conditions on the surface of Earths moon, a change of 1/40,000 would be 1/100 of one degree F.

In a further consideration, assume an increase of 100 ppm of atmospheric CO2 from some external source without any combustion of any fossil fuels. Lets simply increase the volume of the Earths atmosphere by adding 100 ppm of CO2 gas.

In this further consideration, the change in the thermal properties of the atmosphere would be 5 times greater than in the previous analysis. Instead of a change of 1/100 of a degree, the change would be 1/20 of a degree F.

A change of either 1/20 of a degree F or 1/100 of a degree F would not pose any risk to either the safety and well being of the American people or pose any national security risk. There would be no harm from increased drought, heavy downpours, flooding, heatwaves, wildfires, sea level changes, storm intensity or any harm to people, wildlife, agriculture, resources or ecosystems. Temperatures would remain well within the standard deviation for most data sets and well within the norm.

Indeed, atmospheric CO2 levels could increase by up to 2000ppm without any discernible climatological effects based on this data and analysis. CO2 simply will not absorb enough heat to have the effects ascribed in the proposed finding."

Convincing isn’t it? Climate change is then surely just a myth created by scientists to fund their research projects…

In response, one could think that the majority is usually correct (dangerous), and comment that NO single scientific organization disputes climate change (only single scientists), and the vast majority are committed to it as a clear threat. Furthermore, modelling the climate is perhaps the most complex problem on the planet, demanding the use of national supercomputers and a vast army of researchers, and perhaps a one-page calculation is not very convincing.

One could also point out the CO2 has the lowest value of Global Warming Potential compared to all the other gases we are pumping into the atmosphere (it is still the most important due to its volume in the atmosphere – Beware the wise!).

Or we could look at the details of his argument…

Unfortunately, he doesn’t understand what heat capacity is. It is actually a measure of the energy required to raise the temperature for a given substance amount (either number of atoms/molecules or mass). The higher the heat capacity, the less a substance will increase in temperature with energy.

So in fact, by his argument CO2 is actually cooling the atmosphere, and we should pump more in.

This cooling does occur, but is a much smaller effect on temperature than the real mechanism of global warming: CO2 is not sucking in heat; it actually adsorbs and emits long-wave heat radiation that would otherwise escape from the Earth. Its ability to do this is related to the details of the electronic structure of the CO2 molecule and the specific quantum orbitals electrons occupy – effectively the colour of CO2.

We know CO2 acts as a "Greenhouse Gas", and it has increased most in the industrial age. Other gases have also increased, e.g. methane, but CO2 wins due to its volume, lifetime and potential for heat radiation. Water vapour has the highest potential, but the water cycle always balances the system i.e. it rains...

The safest advice when listening to scientific experts is to trust those that qualify every statement with assumptions and possible errors, and use phrases like ‘Difficult to quantify’ and ‘Complex system’. Anyone who appears absolutely convincing in their opinion is almost certainly too wise to be right.

Adam Foster is Professor of Theoretical Physics at the edge of the world (Tampere University of Technology, Finland.) Trying desperately to engage with reality when sober. He started blogging before it existed and then stopped when it did. And now?

1 comment:

  1. One of the big problems that the global warmers must overscme is the deep cynicism that many have,(including me) about the role of many of the people who support man made global warming theory. Too much of scientists's funding comes from agencies and others who support global warming theory or who have a stake in it financially. If a drug company supports research the results are considered tainted. Yet nowhere does there seem to be the same level of scrutiny of global warming data. The 'hockey stick' comes to mind.

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