18 August 2010

Charts

There was some discussion recently about innovating more energy efficiency in the transport sector here and in Europe.  This was at the center of some of it:
Matt Zeitlin | What Price Innovation?

Europeans simply use much less carbon in their transportation sector than we do. And here’s a nice handy chart, using data from the International Energy Agency. This is the per capita carbon emissions in the transportation sector in 2007 of the U.S. and an assortment of wealthy European countries.
Zeitlin then presents the following chart:


I call shenanigans on this chart.  Shenanigans! ( <— you can't just say you're calling shenanigans, you have to actually do it.)

First red flag: the vertical axis doesn't start at zero. This magnifies the difference between the US and everyone else.  Whenever you see that in a chart you need to take a closer look.

What's especially annoying about making this error is that it doesn't enhance the message. Even if you present the chart honestly there's still a big, obvious difference between America and everyone else.  Don't over do it.

Here's the original chart, with just the US and the UK:


Here's what it should look like if it was more honest:


Still a big difference, but not as misleading.

The reason I reduced it to just us and Merry Olde is related to the second big problem here -- this data doesn't correct for the fact that we consume much more transport than these other countries.  I've only been showing two countries because I couldn't be bothered finding the relevant data for more. See here and here. Americans travel ~18,000 miles per person annually, the British "over 7,000." Unfortunately the US data is for 2002 and the British data is 2006. Very far from ideal, but I'm an amateur and I'm busy. Deal with it.


Yeah, we use about three times as much CO2 to move about. Guilty as charged.  We also do about three times as much moving about.

Here's what that looks like:


That's the relevant chart right there. The one Zeitlin presented and others reposted is more about how much transportation is done, not how efficiently it's done. And it's presently misleadingly to boot.

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