48.3 Mature Trees

I’ve owned the Corollavirus for a year now and today the poor beast went in for its MOT. I’ve just heard news that it’s failed, quite comfortably.

In a way, I’m glad — the handbrake was starting to feel really quite dangerous and, while I have no idea what an ‘excessively worn offside front inner tie rod end’ means, it does sound important.

So that’s another £226 tucked into the greasy pockets of my local mechanic.

(Greasy because they work with engine oil a lot, not because they take bribes. Although that might have been a quicker way to get through this MOT.)

Working out the cost of owning the Corollavirus

It’s been quite easy to work out how much this vehicle has cost me over the past year. Including tax, insurance, breakdown cover, servicing, petrol and parking it comes to £3755.55.

It’s also quite easy to say how many miles I’ve driven in the past year: 5338.

Thus, it’s mere child’s play for me to tell you how much the vehicle has cost me per mile: 70 pence. If you like, we can see how that breaks down in a pretty chart:

So far, so good. But what about emissions?

Working out the Corollavirus’s carbon emissions

It’s not particularly hard to tell you how many kilograms of carbon the Corollavirus has emitted while in my possession: 1443.3.

(By the way, when I write ‘carbon’, it’s generally just lazy language for ‘carbon dioxide equivalent’. This metric encompasses not only carbon dioxide, but also methane, nitrous oxide and all other gases and aerosols. You might have seen the shorthand ‘CO2e’ kicking around. Now you know what the ‘e’ stands for: equivalent.)

I can tell you that, if I’d somehow been able to do all these journeys by public transport (I couldn’t have, but that’s a separate complaint I have for the Department For Transport), then I’d have used 1061.8kg less carbon.

(Incidentally, I bought the Corollavirus so that I could do my work as an outdoor instructor so I can tell you that 55 percent of those miles and therefore 55 percent of those emissions are work-related. That’s using a stringent measure of ‘work-related’, but it’s still far lower than I’d hoped.)

I can even tell you that, according to very ballpark figures, my 1061.8kg transport carbon debt (let’s call it) would be hypothetically dealt with by a mature hypothetical tree in a grand total of 48.3 years.

In other words: if I’d planted a tree a decade before I was born, and it’d survived until today in good health, then the Corollavirus would’ve wiped out that tree’s carbon credit in less than 12 months.

If I want to keep up with my car ownership on an annual basis, then I’d need to plant a fresh copse of 48.3 trees every spring and the rest of my years nurturing them into maturity.

I can tell you all these things about the cost of my carbon emissions thanks to a combination of basic accounting and a couple of easy web searches.

What is incredibly difficult to tell you is the unembedded cost of my 1061.8kg vehicular carbon debt compared to public transport.

That’s where the statistical labyrinth begins.

Wait — unembedded?

When we buy and use a Thing, many aspects of that Thing can be said to be ‘embedded’ in the cost of buying or using that Thing.

Incredibly relevant example: when I pay Esso for the petrol I put into my car, a lot of things are embedded, included or accounted for in that price:

  • The cost of pumping crude oil out of the ground
  • The cost of refining the crude oil into fuel
  • The cost of the pipelines and trucks that transport this fuel from across the world to the petrol pump down the road
  • The cost of running the petrol station
  • Etcetera, etcetera, kai ta hetera, and so forth

You’ll observe that one notable thing is missing from that list:


Which is a shame.

Come on then — what are the unembedded costs of driving The Corollavirus?

Good question. This is precisely what I thought would be one simple web search away.

Surely someone on the Internet had one day wondered precisely how much their tank of unleaded was costing the earth? Apparently not.

Luckily for us, it is something that the government has calculated. It just seems that no one’s bothered to figure out, even roughly, what that means for drivers.

As you may have heard, back in 2019, the UK legally committed to having net zero greenhouse gas emissions by the year 2050.

For that to happen, all areas of our economy must take full account of the environmental impact that their activities have on society.

That means digging down into those sneaky unembedded costs.

WARNING: I am not remotely interested in the current value of carbon credits. That data is very easy to find: one tonne of CO2e is currently worth €89 on the European Carbon Credit Market.

Carbon credits are a financial instrument that allows businesses, industries and entire countries to transfer their emissions onto the ledger of another business, industry or country. Naturally, climate change doesn’t give a shit.

We need to go far beyond market economics.

So, in September last year, the Department for Business, Energy and Industrial Strategy published a spectacular policy paper called Valuation of greenhouse gas emissions: for policy appraisal and evaluation.

(By the way, the Climate Action Tracker rates the UK as having one of the most effective net zero policies in the world. Even so, that policy is still ranked as only ‘almost sufficient’ to limit global heating to 1.5C. Must do better.)

It’s rare that I get emotional about government policy, but this paragraph had me screaming in delight (emphasis is mine):

Carbon values are used in the framework of broader cost-benefit analysis to assess whether, taking into account all relevant costs and benefits (including impacts on climate change and the environment), a particular policy may be expected to improve or reduce the overall welfare of society.


Of course, it’s an entirely separate matter whether or not this policy actually gets implemented effectively.

But let’s not let that hold us back because, buried deep down in Annex 1, is a little chart called Carbon values in £2020 prices per tonne of CO2, which gives the expected unembedded costs of our emissions to a future carbon neutral society.

You’ll see that, as we move closer to our 2050 target, the social costs of using carbon increases. A tonne of carbon today is already valued at £4-12 more than it was in 2020.

This reflects the fact that the more we do now to reduce our carbon emissions, the less of a problem we’ll have to deal with later.

As Future Crunch put it so well: saving the world is cheaper than ruining it.

You’ll also see is that there are three different price ‘series’. These take into account different levels of optimism in the underlying assumptions on the ‘future evolution of socioeconomic factors’ such as population and GDP.

For my own estimates, I’ve used the least optimistic assumptions and gone for the ‘high series’ because, quite frankly, if the past sixty years have taught us one thing, it’s that it’s better to err on the side of pessimism when it comes to climate action.

So there we have it!

In 2022, the cost to UK society of one tonne of carbon equivalent emissions is £373.

You’ll notice that this is five times the current ‘value’ of carbon on the European Carbon Credit Market. That’s why carbon credits are bollocks.

Now all I have to do is work out what all this means for The Corollavirus.

Drum roll ple…

Stop right there!

Before we go any further, it’s worth reiterating that there is no way, no way at all, to make up for the greenhouse gases that we emit.

In that sense, our carbon emissions are unquantifiably priceless.

This is where we stop to ponder our fragile existence and long for a society that already valued, say, public transport over private vehicle ownership.

It’s up to us to build that society and I think we car owners can join in by looking at the environmental cost of our driving in a more clear-sighted way.

For example, driving is often, lamentably, cheaper than taking the train. That will remain the case until our government acts to tilt the economic condition back in favour of public transport.

(And it is kinda on their radar, as shown by the recent re-opening of the Okehampton line into the heart of Dartmoor. But I think we can do more.)

But what if drivers took into account the hidden environmental cost of their journeys? Might knowing the exact monetary cost to future generations (or just their senile future selves) of their joyriding tip their economic calculations in favour of taking the train next time?

Maybe, maybe not. Quantifying these costs doesn’t mean that I beat myself up about driving — life is hard and we do what we can. But it does mean that I at least understand what I’m doing to the world when I put my pedal to the metal.#

Anyway. Where were we? Oh yes —

Drum roll please…!

At 168g CO2e per kilometre, driving one mile in my car has an implied environmental cost to society of ten pence.

Let’s update that pretty chart, shall we?

When I’m 68…

I started this whole rigmarole because I wanted to take responsibility for the additional unembedded environmental costs that came about as a result of buying a car.

And, thanks to the policy wonks at the Department for Business, Energy and Industrial Strategy, I can now put a precise value, in pounds and pence, on what I’ll call my Unembedded Environmental Costs Premium — UEC Premium for short.

For all my driving miles over the past year, all those ten pences add up to £527.55.

Rather neatly, my UEC Premium last year comes to about the same price as my car insurance, tax and breakdown cover combined.

So maybe I could think of the UEC Premium as a sort of insurance, tax and breakdown cover for the environment.

That might be going a bit far, but the point is that this isn’t an abstract number.

This is an estimate of the out-there-in-the-world environmental costs that no one is currently budgeting for in the price of driving.

This is damage caused by burning fossil fuels that will need to be paid for, by someone — a living, breathing human being like me — at some point in the future.

I’m choosing to at least acknowledge these unaccounted costs and use that UEC Premium in a way that might go some way to repairing the damage caused.

I think it’s important to do this, because, like bank loan interest, environmental damage compounds. That’s why the policy paper shows a tonne of CO2e as being cheaper to deal with today than in 2050.

The more we do now, the less ‘interest’ we’ll have to pay on our emissions later.

In this case, the past year of me driving the Corollavirus has cost society an unaccounted £527.55. A year of driving such a vehicle in 2050 will cost society an unaccounted £816.48 (assuming zero inflation).

At this point, you may be thinking that the UEC Premium is surprisingly affordable and that you’d happily pay an extra few hundred pounds to make climate change go away and stop bothering you.

Sadly, it doesn’t quite work like that. There is, again, no way, no way at all, to make up for the greenhouse gases that we emit. Once they’re up in the atmosphere, greenhouse gases can continue to affect the climate for millennia.

But I think there is value in recognising that a few hundred pounds, for many people, myself included, is an unembedded cost that we can afford to contribute to the fight for our futures.

The question is: what to do with that UEC Premium?

As you can probably guess, I’m not going to buy any carbon credits. Perhaps more surprisingly, I’m also not going to invest in any carbon offsetting programmes, like tree-planting.

I won’t go into why carbon offsetting programmes tend to be problematic, but I rather like the way it’s been put by the Guerilla Foundation:

Carbon-offsetting does seem to be a ‘get-out-of-jail-free’ card for polluters to keep polluting while greenwashing their hands.

Instead, I’m going to follow their lead by giving to:

activist groups such as Stay Grounded or Yes to Life, No to Mining, that are trying to radically revision and restructure major carbon emitters, while trying to limit [my] own pollution to the barest minimum.


In 2050, I’m going to be 68 years old.

I’m excited to celebrate my sixty-eighth birthday in a just — and net zero — society.

Let’s do it.

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David Charles is co-writer of BBC radio sitcom Foiled. He also writes for The Bike Project, Thighs of Steel, and the Elevate Festival. He blogs at davidcharles.info.

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