Individual Liberty — Individual Responsibility 

A little math (very little)

In forty years of measurement there was a twenty percent increase in the concentration of Carbon Dioxide in the atmosphere. That sounds like a lot doesn't it? Twenty percent. One part in five. Why that's positively huge isn't it? (I get this number here.)

Well, it might seem so, but numbers like that are simply misleading. The question that isn't asked is twenty percent relative to what? Don't you think that that question matters?

Perhaps it might be instructive to look at a couple of charts. First, lets look at a chart starting at forty years ago, and at "100%" and ending at today at "120%". Look at the line on this chart.

When you present the data that way it looks pretty alarming doesn't it? Why that's a really steep slope on that line, things must really be catastrophic.

That's why I ask the question "twenty percent relative to what?".

Currently the concentration of Carbon Dioxide in our atmosphere is 385 parts per million (for those bothering to figure out percentages here, that means that 0.038 percent of our atmosphere is composed of Carbon Dioxide). I take the figure 385ppm from John Coleman. John Coleman also provides the figure of twenty percent for the amount of increase in Carbon Dioxide The twenty percent increase is relative to that tiny amount. But, let's continue.

To figure out what the concentration was forty years prior to that measurement, based on the idea that the concentration has increased by twenty percent over forty years all we need to do is a little math.

Let's assume that the concentration was "X" forty years ago. Adding twenty percent to "X" is the same as multiplying "X" by 1.2. So 1.2X = 385 parts per million.

In other words, X = 320.8 parts per million. but just to make sure the slope of our line goes up a bit, let's assume it was only 320 parts per million. Coleman indicates that it was 315 parts per million in 1958. That was fifty years ago not forty as our first reference gives us, so I'll stick with 320 and forty years. That will give us a steeper slope on both of our graphs anyway and emphasize the bad news.

Now here's another chart for you... drawn to scale as well as I can figure. The vertical axis represents the total amount of Carbon Dioxide in the atmosphere, relative to the rest of the atmosphere. The horizontal axis is still in years. Look at this chart and compare it to the previous one. This is the effect of forty years of pumping Carbon Dioxide into our atmosphere when you consider the atmosphere as a whole.

Why did I choose the scale I did? Well, there are one million parts of atmosphere per million in our atmosphere. That's why the maximum value of the scale is where it is. If there were no Carbon Dioxide in the atmosphere at all, that would be zero parts per million. That's why that's the minimum value. When you view the amount of Carbon Dioxide in the atmosphere that way, it's pretty hard to see the effect of forty years of change isn't it? I guarantee you if you set the bottom of the scale at 320 and the top of the scale at 385 the slope of the line would be identical to the first chart above. If you don't believe me, here's a link to the spreadsheet I used to generate the chart. Open it and change the limits on the Y axis to see. It's just that when you compare 320/1,000,000 to 385/1,000,000 the difference in the numbers are pretty small. We're talking about the difference between 0.032% and 0.0385%. Chop off anything on the order of a thousandth of a percentage point and we're talking about the difference between 0.03% and 0.03%.

Maybe that's why that second line is so flat.

This doesn't mean that we aren't pumping a lot of CO₂ into our atmosphere. All I'm really saying in this post is that twenty percent of a trace amount is still a trace amount. I'm not going to hold my breath over that.