Comments on: Walking does more damage than driving

By: DV

DV — Wed, 15 Apr 2009 15:31:05 +0000

I read your blog for quite a long time and should tell you that your articles are always valuable to readers.

By: captain sensible

captain sensible — Wed, 12 Sep 2007 22:36:42 +0000

Most importantly the research appears to omit the CO2 cost of drilling, refining, transporting and storing the fuel for the car to burn on the way to the shops, which seems rather daft when this is exactly the kind of metric that the calories burned by walking are compared to.

Perhaps a more useful (and might i suggest ’scientific’) study would have been to compare the amount of CO2 released in producing and delivering the energy sources (petrol, electricity, food) required for several different methods (car, bicycle, tram, walk) of making the same journey.

Maybe Mr Goodall is trying to draw attention to the fact the the devil is in the detail when it comes to trying to audit specific actions for their environmental impact?

By: Joe

Joe — Mon, 27 Aug 2007 12:11:16 +0000

To be fair to the article, they seem to be slightly sceptical of the claims of this scientist anyway and it does point out that the whole picture wasn’t painted thanks to things such as road maintenance. Doesn’t look like it took the overall cycle of a car, from builing it to scrapping it, into consideration either. I don’t think anyone would advocate the use of a car instead of a short walk to the shops.

I don’t think you can call the article junk science – there’s a good point that some of the onus for greenhouse emissions do need to be passed back to the manufacturer rather than the consumer, such as the miles food travels, and the amount of packaging that comes with some foods.

By: Allen Maher

Allen Maher — Fri, 24 Aug 2007 21:25:10 +0000

A few problems with the calculation… one the assumptions of a 3 mile nearly 5Km trip to the grocery which is a frightfully long walk, second it does not take into account that said human being will be burning some calories and in the same amount of time anyway… so there is less cost than one might suspect.

Food energy in a healthy diet (and one assumes 400 pound whopper addicted suburban slobs are not going to be walking three miles to the store) comes primarily from carbohydrates like those found in grains and other vegetables rather than protein and lipids from afore mentioned beef sandwich.

When you look at the krebs cycle in cellular respiration you will notice that carbohydrate food energy is tremendously more efficient than protein or lipids as food energy (though the others store more energy per gram). Carbohydrates from rice, wheat and the like are very much lower in greenhouse gas production per calorie than meat or milk.

It is no more than 500m to my nearest grocery store (about a quarter mile) and I regularly walk it, without the aid of milk or meat. If you are 3 miles from the nearest place where you can get food… you have more problems than diet versus gasoline.

This article is another example of junk science making silly claims without any real investigation of the facts. Eat healthy, walk more and get the heck out of the suburbs.