Where we live the council collects recycling, however the quantity you can recycle each fortnight is sadly limited. When I get big cardboard boxes I keep them in the garage until I have. a pretty sizeable pile which I can take to recycle. However, the household recycling centre is a 30 minute round trip in a car (sadly not electric!)

My concern is that the net impact of this trip might be negative! Is there any rule-of-thumb I could apply to determine the benefit of recycling versus the impact of driving?

(I do of course try not to make a dedicated trip for this purpose, combining with other nearby activities)

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    refuse reduce reuse recycle rehome replant rot... perhaps the real question is why you have so much to recycle?
    – gerrit
    Aug 19, 2019 at 7:56
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    That's a fair point @gerrit - and I thoroughly understand that reduction far outweighs the benefits of recycling. To be specific I don't have "so much to recycle", I stockpile in my garage and only need to make this trip once every few months. I also reuse the cardboard for all sorts of other things where possible.
    – ColinE
    Aug 19, 2019 at 10:48
  • Do you only ever have cardboard to take? Even a small amount of scrap metal (worn out bike parts in my case) probably offsets more CO2. Now if only they'd let me into the tip on a bike!
    – Chris H
    Aug 20, 2019 at 15:55

2 Answers 2


A 30 minute drive would be approximately 15 miles, an average small car produces 200 grams of CO2 per mile, so you are emitting about 3 Kg of CO2.

The CO2 footprint of new plastic manufacture is about 6 Kg CO2 per 1 Kg of plastic.

For recycled plastic manufacture its about 3.5 Kg CO2 per Kg of plastic. So the nett difference is 2.5 Kg CO2.

Supposing that world needs plastic its going to churn it out whether or not you go to the recycling centre, but your decision to go will save 2.5Kg of CO2 for each Kg of plastic you take.

Thus, to cancel out your petrol car's CO2 emissions from driving as long as you are recycling more than 1.2 Kg of plastic per trip to the recycling centre then there is a net reduction in the amount of CO2 potentially emitted in the future manufacture of plastic.

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    Thanks Christopher - so the key unit to use in calculation is CO2? I'll use this as a guide and do the same maths for cardboard also.
    – ColinE
    Aug 19, 2019 at 10:50
  • From an ecological perspective CO2 is perhaps the best measure. Although usually I convert everything into money which helps to contain more external costs. For example, you have to pay for the petrol but the money might be better spent on buying products with card packaging instead plastic packaging, or just offsetting the CO2 and putting it in the general trash. Also the cost of producing virgin plastic is about six times the cost of recycled plastic (£1,200 per tonne versus £200). Is it worth spending £2 of petrol to save £1 worth of plastic and £0.10 of CO2? Maybe. Aug 19, 2019 at 11:11
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    @ChristopherGilmour converting to money is handy but given the large effective subsidies for fossil fuels it can significantly distort the calculation
    – Chris H
    Aug 20, 2019 at 15:56
  • @ChrisH In the UK more than half the price of fuel is tax, when the government is subsidising fossil fuel, they're using the money we've already handed over when we bought the fuel. I don't know if it cancels itself out but if the subsidies didn't exist fuel would still be roughly the same price. Aug 21, 2019 at 11:23
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    That's one way of looking at it, but it doesn't take into account the current value of historic subsidies for fossil fuel infrastructure, or the costs imposed on all of us from NOx, particulates, and of course CO2. The tax/subsidy balance varies a lot between countries - in the US fuel is cheaper, in some of the UK's nearest neighbours it's 10-20% more, so there's clearly room for quite a lot of variation
    – Chris H
    Aug 21, 2019 at 11:40

If you are able to plant a tree you can use the cardboard to mulch around the base and suppress weed,grass competition. Soil microbes turn it into soil that feeds the tree. zero driving

  • I agree the OP could compost some of the cardboard, but it sounds like he regularly has a pile of cardboard and there is only a limited quantity you can compost at a time.
    – THelper
    Nov 10, 2019 at 7:23

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