Machine Design

Greenhouse gas or just hot air?

John Allen Paulos is a math professor and pundit with a reputation for poking fun at educated but mathematically illiterate people.

John Allen Paulos is a math professor and pundit with a reputation for poking fun at educated but mathematically illiterate people. He even wrote a popular book about innumeracy, the inability to deal comfortably with the fundamental notions of numbers and chance.

Paulos is genuinely irked by individuals who have university degrees but cannot quantify. This makes them vulnerable to scams and pseudoscience, he says. Paulos also is convinced a sizeable chunk of adult Americans couldn't pass a simple test on percentages, decimals, or fractions.

I recently happened upon what may be an example of the innumeracy Paulos ridicules. Surprisingly, it was in a publication directed at graduate engineers. The subject was carbon sequestration. The author quoted a professor of environmental engineering as saying, "Thirty percent of carbon dioxide emitted into the atmosphere originates from fossil-fuel-fired power plants."

Whoa. Thirty percent of all carbon dioxide? A quick look at the Wikipedia page for atmospheric carbon dioxide turns up the fact that the sum total of all man-made carbon-dioxide emissions account for only about 5% of the CO2 in the atmosphere. What the professor certainly had meant was that 30% of man-made CO2 came from power plants. That comes out to a much less ominous sounding 1.5% of total atmospheric CO2.

It's not clear whether the author of this piece realized the discussion centered on a relatively small percentage of the atmosphere's CO2. The writer seemed oblivious to the comparative magnitudes involved.

Unfortunately, it's easy to find other comments in the media that seem toarise out of a similar cluelessness. Even politicians making decisions on greenhouse gas legislation are apparently prone to the same cognitive problem. When California politicians quote findings that their state is the world's 12th-largest source of greenhouse gases, for example, one wonders whether they understand this statistic pertains only to emissions that are man-made. It's fair to ask whether these politicians, given such information, could calculate California's contribution to atmospheric greenhouse gases as a percent of the total.

On this point, Paulos' comments about innumerate political-office holders are not comforting. He relates the story of a 1980 Presidential candidate who reportedly had to ask his press entourage how to convert 2/7 to a percentage, in an effort to help his son with a homework problem.

Innumeracy about CO2 levels is unfortunate because the topic has become politicized. For my part, I suspect a better numerical understanding of CO2 levels would lead to more skepticism about the agendas of some radical environmentalists.

Instead, we create hot air with arguments that don't have much to do with legitimate CO2 science. And that's too bad. People who might otherwise concur about the need for alternative-energy schemes instead get locked into name calling and acrimonious CO2 debates.

And that brings us to the "green" themed issue you see in front of you. There are a variety of reasons why research into nonfossil-fuel-power generation is a good idea, even if its impact on greenhouse gases is zilch.

— Leland Teschler, Editor

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.