How to live above sea level

Most women wake up in the morning with tousled hair, but their eyebrows look much the same as when they went to bed. Mine have been dancing with wolves. A staggeringly wide range of grooming products exists to maintain kempt brows, but research also reveals that the simple application of castor oil will do nicely. This is one small purchasing decision for me to make, here in the privileged West where I have multiple options and can choose according to quality and price. What my decision will not include is the carbon cost of each one - because I don’t know it.

Too piffling to rank as a moment for green activism? Perhaps. But scale this up over a day, a year, a family, a nation, and the effect of localised carbon accounting is not negligible. The tedium of sorting our waste for various recycling bins is accompanied by a vague sense of righteousness, but it’s the not knowing that makes it seem so hollow. What difference am I actually making? It’s the same with shopping: if I don’t know the carbon cost of an item, I cannot calculate the accrued sum of my consumption habits. A ration book might help, but in Britain these are forever linked to stockings and the horror that is Scrag End of Lamb. They are also faintly moral, carrying implications of guilt and debt, and today’s credit-savvy generations are more likely to accept straightforward empiricism: a personal carbon budget.

The recent Extinction Rebellion sit-ins and Greta Thunberg’s school strikes have concentrated on highlighting the environmental damage caused by global industries. Commerce in turn claims that it simply responds to public demand. If enough people want pink plastic garden furniture, a factory in Lithuania or Turkey will supply it, and often at a dirt-cheap price. But if the carbon bill for its manufacture were also provided to the potential buyer, they could decide if the consequence - for example, tipping their monthly CO2 budget over into the red - is not worth it.

On a daily basis, you might want to run the washing machine half empty rather than wait for a full load, or to drive rather than catch a train to work, but having to tally the carbon count of those actions would at least make you think twice. Few people willingly pollute their own environment - the bagging and binning of pet poo shows that people do care about public spaces. They could care more usefully if they knew the carbon cost of each bulging little plastic bag which ends up in landfill, where those that decompose fill the surrounding air with methane clouds, and the millions that don’t are an ecological disaster.

Does this constant reckoning sound like hell on earth? Is it a worse hell than the slow, dustbowl deaths we are set to endure this century unless every human reduces their energy consumption? Yeah, sounds like rhetoric to me too. That was before I listened to Losing Earth: The Decade We Almost Stopped Climate Change. In Radio 4’s serialisation of the book by Nathaniel Rich, the author equably and steadily reveals the 1979-1989 political manoeuvring which discarded the opportunity to prevent today’s global warming by continually choosing now over later. Rich notes: ‘The lag between the emission of a gas and the warming it produced could be several decades. It was like adding an extra blanket on a mild night: it took a few minutes before you started to sweat.’

There’s something in our primitive nature that (religion aside) means we need to actually see change before we believe it. Hence our response to photos of arctic melts, polar bear starvation and plastic-throttled penguins: they have much more effect than the unemotional purity of scientific data. But numbers are what we need if we are to think green each time we wash, dress, eat, travel: what precisely does that behaviour do to the tab? The imagined healthier lives of the grandchildren we’re yet to have counts for nothing when people are happy to welcome a warmer climate because it means they can wear shorts all year round.

This would require an organised, accounting structure. And an app! (the use of which would have to be carbon-costed but let’s not lose momentum too early). It’s a dream, I know, but if the sellers of goods were forced to quantify and display their carbon costs, buyers could read the units on the packaging just like nutrient percentages on a tin of soup. We all hate new rules that initially make things harder - look at the fuss over smoking in public, congestion charges, plastic shopping bags - but humans are adaptable, and most that I know feel powerless to halt global warming. Everyone knows what it takes to live within their financial means; a CO2 account should be just another slate to manage.