Crunching the Global Warming Numbers

Anybody who reads me regularly knows that I'm kind of a nerd, and also knows that I'm very interested in the issue of global warming. So, you won't be surprised to know that I've found all the raw data I can get my hands on, and loaded it into Excel to play with.

Yes, there's nothing like just looking at a set of data, drawing graphs, comparing one thing to another, just rolling around in it. Sometimes when you're off doing something else, like maybe a long run, an idea jumps out at you, some way of making sense of all the numbers.

One thing I found when comparing the levels of CO2 in the atmosphere to the average annual global surface temperature is that there is strong mathematical correlation between the two. Correlation doesn't necessarily mean causation. But what I found is that the strongest correlation (88.3% correlation) is between CO2 level in one year and temperature 14 years later. That not only gives us one more piece of evidence that one is a causal factor in the other, but it also gives us a time frame. When you burn a gallon of gasoline in your car, you are impacting the future climate of the planet. And that impact may be felt immediately and may last for decades, but the strongest impact is about a decade and a half in the future.

What does this mean? Well, for one thing, even if we stop burning fossil fuels today we will still be seeing the impact for a while. But it also means that our actions today will have an impact within the foreseeable future. The impact of burning a gallon of gasoline today on the climate twenty years hence falls to the same level as its influence on this year's climate. So, if we can get our fossil fuel burning under control, perhaps in twenty years we will start seeing a significant difference.

What else did I see in the data? Here's one: Right at the time of World War II CO2 levels in the atmosphere stabilized, and even fell a tiny bit. From 1939 to 1948, there was essentially no change in CO2 in the atmosphere.

Why? I'm not sure, but perhaps the level of industry was reduced, and gas shortages caused reductions in driving, and that may have been enough to get our CO2 emissions to a reasonable level.

What happened with global temperatures then? Well, as you might guess, they stabilized or fell immediately after WWII. Between 1946 and 1957, global temperatures fell by about 0.12 degrees C. Temperatures didn't really start rising again until the 1970s, about 20 years after the CO2 levels started really rising again.

What can we learn from this? Well the most positive thing I take from this is a confirmation that not only do temperatures go up when CO2 goes up, but temperatures go down when CO2 goes down. Plus, we have a concrete example of mankind actually influencing global warming in the correct (lower) direction. This tells me that if we reduce our CO2 output to a level at which its atmospheric concentration is stable, we might, just might, be able to get the temperature increases under control.

Of course, our annual CO2 increase today is about five times as high as the annual increases in the 50s, so it won't be easy to get it under control. Much more of the CO2 is being originated in places that aren't the U.S., so there needs to be a truly global attack on the problem.

But at least it seems technically feasible.