This is adapted from an email response I sent to my brother-in-law who buys into Jim Inhofe’s “Global Warming is a Hoax and/or Scam”. He is very well informed on technical issues and works in a high tech field, so he’s no dummy. He just doesn’t have the information I do. He laughed at me for asserting that I knew more about science and how science works than Inhofe does. This is not an assertion I make lightly and there are few areas in which I am that confident. I wrote in all fairness that Inhofe knew more about being a senator than I ever will.
I don’t need scientific consensus or Al Gore’s help to demonstrate I know more about global warming than Senator Jim Inhofe. Let me state an artificially induced warming is not mutually exclusive with natural warming (and cooling) cycles. Some people think they are.
First of all the Earth has a very complex climatic system. There are many things we still don’t understand about it. But I assert that scientists who study the Earth’s climate know enough. Yes, the Earth has gone through many natural warming and cooling cycles over the eons. There have been times when it was much warmer and the seas were much higher and there have been times when it was much colder. Those cycles can be correlated to orbital variations, tilt variations, and the sunspot cycle.
That being said. It can all be boiled down to carbon dioxide and basic laws of physics. For the last 150+ years humans have been extracting coal, oil, and natural gas. We’ve been burning those fossil fuels and producing carbon dioxide at a faster rate than the the biosphere can absorb or process them. As I said there are a lot of complex factors involved, but we can pick out the signal from the noise. There’s other evidence I won’t address in this post, tree rings, ice cores, sediment cores, and computer modeling.
In chemistry there are three types of systems, open, closed, and isolated. An open system means there is an exchange of matter and energy. Closed means there is only an exchange of energy. Isolated means no exchanges. Earth is an closed system. There is no exchange of matter (meteors are such a tiny fraction we can safely ignore them). There is only the solar energy we receive from the Sun and what we Earth radiates back out as infrared and reflected light.
Let’s do a basic thought experiment. We’ll take two two liter bottles and fill one with air and another with carbon dioxide and placed a thermometer in them and then put both bottles under a sun lamp. We’ll place the thermometers under a piece of cardboard so as not to be heated directly by the lamp. We’ll record the temperature before we start and then check it at half hour intervals. Because carbon dioxide absorbs infrared better than air does, we’ll see that that bottle gets warmer.
Prior to the Industrial Revolution scientists have been able to determine the level of carbon dioxide in the air was around 280ppm. It is now close to 380ppm, about a 36% increase. This does not correlate to a 36% increase in global temperatures. C02 has been measured directly since the 1950’s and has steadily increased since then. And so have the average global temperatures.
How do we know that the increase in carbon dioxide is from fossil fuels and not from natural sources? Carbon-14. It is produced in the upper atmosphere when Nitrogen is struck by cosmic rays and loses a proton. Or rather a neutron is added and a proton is kicked out. Carbon-14 is incorporated into every living thing at a known rate. It fluctuates very little and scientists take these minute variations into account when using carbon dating. Carbon-14 decays at a known rate and after about 30,000 years it has decayed to the point of not being measurable any more.
Fossil fuels buried deep underground are negligibly affected by cosmic rays because the rays don’t penetrate more than a few yards. By burning fossil fuels humans have changed the ratio of carbon-12 to carbon-14 in the atmosphere. This is one of the ways we know that the extra carbon in the atmosphere is from humans burning fossil fuels.
In full disclosure, scientists started measuring carbon-14 in the atmosphere shortly before above ground nuclear tests. The hydrogen and atomic bombs spiked the amount of carbon-14 in the atmosphere making measuring the ratio difficult. Those levels began to drop after above ground tests stopped. There is also natural radioactivity in the ground that can affect fossil fuels and produce some carbon-14, so they aren’t totally devoid of it, but it is not created at any where near the same rate as it is in the atmosphere.
You’d think this might weaken this line of evidence but it doesn’t. This is how science works. You take into account what might affect what you are trying to study. This isn’t the strongest line of evidence that humans are responsible for global warming, but one of many lines.
It is very sad that science has become so politicized that there is a huge gulf between what the scientists know and what the public knows. And I can point fingers at people like Inhofe for widening that gulf. Gore may have his heart in the right place, but he also distorts things and sometimes harms public discourse, but doesn’t outright lie like Inhofe.
Andrew Rice who is challenging Inhofe for Senate understands that global warming is a problem, and we need to do something about it, but it’s not just that. Inhofe is fundamentally anti-science and someone who refuses to take into account how science works and should inform their political decisions is not someone who will help Oklahoma.