Sources of CO2

Cynthia Allen recently stated the people are unwilling to make the kind of sacrifices that are needed to combat climate change (1). Her column shows a limited understanding of greenhouse gas production.

Ms. Allen is wrong when she implies that home heating and cooling are a major source of energy wastage. Actually, homes and businesses together generate a small fraction of greenhouse gasses. The three largest sources are electric power plants, motor vehicles, and industry.   Together they account for over three-quarters of greenhouse gasses (2).

But there is good news on all fronts. Emissions from power plants have been dropping sharply (3). Bloomberg recently predicted that electric cars with efficient motors will become cheaper the gas autos within ten years (4).  And industry has been saving energy (5). All in all carbon dioxide emissions have fallen 14 percent in the last ten years (6).

We are living in an era of great technological change. There are many opportunities for people to save money by saving energy. But we need to realize that the big changes will come from outside the home.


(1) ‘Few are willing to support climate control at home’, Columbus Dispatch, June 12, 2017

(2) US EPA ‘Sources of Greenhouse Gas Emissions’,, accessed 13 June 2017

(3) Georgina Gustin, ‘U.S. Power Plant Emissions Fall to Near 1990 Levels, Decoupling from GDP Growth’, Inside Climate News, 14 June 2017,

(4) Jess Shankleman ‘Pretty Soon Electric Cars Will Cost Less Than Gasoline’,, Bloomberg, 26 May 2017

(5) U.S. energy Information Administration, Electric Data Browser

(6) ‘Retiring nuclear plants may undercut climate goals’, Columbus Dispatch, June 14, 2017

Global Warming is Alive and Well (in Columbus)

To illustrate some of the poor reasoning that goes into claims of global cooling (15,000,000 hits on Google) I determined the trend in annual degree days for Columbus from 2000 to 2013 (a).

Heating degree days can be used to estimate how much you need to use your furnace in the winter. Typical values for Columbus are around 5000. The number of heating degree days has been decreasing at a rate of 0.2% per year, indicating a trend towards slightly milder winters.

Cooling degree days can be used to estimate how much you need to use your air conditioner in the summer. Typical values for Columbus are around 1000. The number of cooling degree days has been increasing at a rate of 1.7% per year, indicating a trend towards warmer summers.

Of course, this does not prove that global climate change is real.   It actually illustrates a common fallacy – drawing a conclusion from one measure of change over too small an area over and over too short a time.  The web site <> covers all of the faulty reasoning that characterizes climate-change skepticism.

(a) The degree day annual totals for zip code 43215 were obtained from using a reference temperature of 65 F. Degree days are defined in <;