Monday, July 27, 2009

Table for one

INCPEN, The Industry Council for Packaging and the Environment, have produced a super leaflet called Table for one. It is a detailed document full of numbers estimating the energy footprint of one typical British person's food.
All the numbers are expressed in MJ per week. There's lots of nice diagrams, some showing the breakdown of the energy footprint of, say "Snacks" between food supply, primary packaging, transport packaging, transport from factory, retailing, travel to shops, home storage, and home cooking; and some showing summary numbers.
The one below summarises how much energy the average person gets from all their food (73 MJ/week (2.9 kWh/d)), how much it costs to produce and deliver it (337 MJ/week (13.4 kWh/d)) and how much energy is used to produce the packaging (35 MJ/week (1.4 kWh/d)).

The final figure below shows the breakdown of the footprint by food type, and there is a clear message about meat consumption (as I guessed in my book): meat has a bigger energy footprint than any other foodstuff. [They were assuming that the average person gets 7 MJ per week (1,700 calories per week, or 242 cal per day) of energy from meat; this is a weight of 1029 g per week (147 g per day). For comparison in Ch 13 I assumed a carnivore ate 227 g per day.]

It's nice to see an industry publishing such clear energy-footprint numbers! A copy of "Table for one" (pdf) is sitting on my website. I assume INCPEN don't mind my sharing it there.


John A said...

Yes but isn't Incpen the organisation that lobbies government to slow down any legislation against plastic and other unsustainable packaging. This is surely just an attempt to distract us.

Heather said...

I agree with John A. It seems like a straw man to me. I mean, the numbers and graphics are nicely done and consistent, but the clear 'take home' message is: "packaging doesn't use much energy". Does anyone think that it does? When I hear people protesting the evils of packaging, it's always from an ecological point of view, not an energy one. Plastic bags getting into the soil in Africa and destroying permeability; plastic swirling around the ocean and blocking light and being eaten by turtles - that kind of thing. Things that happen at the disposal end of the equation and which have nothing much to do with energy.

And as a side point, you could argue that the packaging energy numbers are underestimates anyway. The plastic is potential fuel, and by using that oil to make plastic you are not using it to make electricity or move vehicles or whatever. (you could burn it later, but we don't) I can't decide if I think that should be factored in or not.

Finally, I think it's cute that sugar, oil and snack foods are all roughly energy neutral or negative: you get more out than you put in. Presumably because they're discounting the energy the sun puts in to make the crops grow. So, for the sake of energy efficiency I shall focus on these foods from now on ;-)

--Heather :-)

David MacKay FRS said...

I have a different view on the numbers for packaging. Yes, their leaflet shows that packaging is not the biggest energy-sink in your life; but I'd say it also shows that packaging IS significant - it's above the "1%" threshold! Anything that is above 1% is worth attention.

Aleko in Germany said...

Agree with all the above comments, my biggest problem is that I don't believe the numbers.

For instance, I don't think people use as much energy storing bread as I do milk (bread sits in the bread bin, milk sits in the fridge). Don't understand how I could use 3 times more energy storing fish as cooking it, assuming it doesn't spend 3 months in the freezer first. Or how I could use so much energy cooking cereals (unless it is mostly Uncle Ben's not Kelloggs').

Seriously, I have no idea about the research and assumptions behind these numbers. The INCPEN website is just designed to deflect criticism of packaging - and I can't find any more data from Dr Jan Kooijman. I can only conclude that packaging is a bit worse than quoted and that the leaflet is not as super as first supposed.