Month: February 2008 (Page 2 of 2)

I tend to be a contrarian. It’s my nature and sometimes to my disadvantage. For a long time I was a global warming skeptic for two reasons: 1) my contrary nature and skeptical attitude towards the media 2) I fell for the disinformation campaign promulgated by the likes of ExxonMobil. It wasn’t until I saw the before and after pictures of glaciers (all retreating) from around the world that my contrarian position began to melt.

The problem I had was the way the media portrayed global warming, for the most part they do it badly. They used the consensus as a bludgeon to quell dissent. To me this scientific consensus smacked of argument from authority. Granted a thousand climate scientists agreeing on the evidence carries more weigh than a thousand preachers agreeing that the world is going to come to an end realsoonnow. To me it doesn’t matter if a thousand people agree one one thing. They could still be wrong. It is the evidence that matters.

I misunderstood argument from authority as being all bad. Mainly because it’s carryover from when I argued with Creationists who used the Bible (which translation?) as their ultimate authority. It’s based on trust. if a dozen climate scientists agree their research agrees and that the climate is warming I can trust their science. But if a dozen engineers agree that evolution wasn’t possible and that God must have created all living things, I can’t trust their reasoning because though they may be expert engineers they aren’t experts in biology nor have they done any paleontology.

No authority is absolute. Science is always changing. There are things we don’t know. Uncertainty is built into the very fabric of the way we observe the Universe. Is a photon a wave or is it a particle? When we get into the very messy realm of history where experiments are difficult to do, we must rely on the inductive capabilities of the scientists to gather data and to build a coherent but sometimes incomplete picture. Generals are always working with incomplete information during a battle, but they still must make decisions on the best knowledge available. Scientist too make conclusions on the best data and theories available and they are testable.

So here’s my basic physical reasoning about humans causing global warming. Carbon 14 has a half life of about 5700 years and after about 40,000 years it becomes useless for dating things. Fossil fuels are hundreds of millions of years old. All the C14 should basically be undetectable, so by measuring the ratio of carbon isotopes in the atmosphere over a period of a hundred years, we should be able to detect the clear signal that we are responsible for the increase in carbon. It’s not that simple.

Carbon 14 can be found in coal and oil. Some scientists think that it could be due to natural radioactive decay or organisms living at those depths. Though how the C14 would get into the organisms isn’t explained. So I’ll go for radioactive decay of uranium. It also depends on where the fossil fuels are gotten from. Some have very low proportions of carbon-14 as expected, others have more. However we should be able to determine the minimum and maximum ratios expected and compare them to the atmosphere ratios. Is the top of range still much lower than atmospheric C14? I suspect it would be. We might still be able to tell. Finally, another problem arises with the atmosphere.

Back in the 1950’s we started exploding atomic bombs in the atmosphere. This created a spike of C14. It has been decreasing since then. Prior to the 1950’s we did detect that C14 ratios were decreasing. The thing to do is to look at the ratios of carbon in ice cores and sediment cores. Although my physical reasoning is good there are a lot of other factors that need to be looked at, so though we know the rate at which carbon 14 decays we may not have enough data to use it as a reliable fingerprint.

Carbon 13 is another stable isotope of carbon. There is less of it. Most plants prefer plain old carbon 12 to carbon 13. Corn however will metabolize C13, so it’s signature in our food supply is unmistakable. We could even do isotopic analysis of our hair to determine how much corn is in our diet. It’s a lot. I’ve already written a post on carbon 13. There have been studies that have shown the ratios of C12 to C13 changes during periods of cooling and warming in sediment cores.

Basically, I wanted Carbon 14 to be the smoking gun. It could be but I need to do more research to answer that question. On the face of it it sure seems like it. Of course global warming deniers go to great lengths to protect their cherished beliefs the same way creationists continue ignoring the evidence of evolution. There are still debates within the scientific community over global warming. It’s influence on Hurricanes is hotly disputed, but the evidence is pointing in that direction. Of course, there are many lines of evidence (a.k.a. “smoking guns”) that point to humans as the culprit responsible for global warming, but some humans like global warming deniers are immensely resistant to reason and logic and evidence.