Sainsbury's to slash their emissions as 15-year campaign bears fruit

A major UK supermarket is going to cut its greenhouse gas emissions by almost a third by changing just one thing about the way they do business. How's it possible?

I've had this growing feeling for a while now. There's no putting it off any longer. I'm just going to have to accept that not everyone is as fascinated by the spectroscopic properties of different greenhouse gases as I am.

For example, I find the recent revelation that methane's global warming potential of 25 is probably an underestimate fascinating. But I concede that, in the pub, talking about football is probably a safer bet.

But what if I told you that there are gases which are up to 3000 times more potent in their global warming effect than carbon dioxide? No, you still wouldn't be interested. But it does explain how Sainsbury's hope to cut their greenhouse gas emissions so dramatically.

We have campaigned for a long time to get companies to stop using things called 'f-gases' as refrigerants, because besides being useful for keeping things cool, they are also dangerous pollutants. The original bad boy F-gases were CFCs - chlorofluorocarbons - which were used extensively in fridges and other cooling systems until we realised that, as well as keeping milk cold, they had the unfortunate side effect of punching a massive hole in the Earth's Ozone layer.

Remember when that was the most high-profile example of looming environmental peril? Ah, happy days.

Anyway, thanks to some groundbreaking environmental legislation called the Montreal protocol, which received widespread support from major industrial countries, (unlike some bits of environmental legislation I could mention), CFCs were banned, to be replaced by HFCs - or Hydrofluorocarbons.

Everyone was very keen on HFCs because they did a similar job to CFCs but didn't damage the ozone layer. But unfortunately there was a catch, because despite being ozone-friendly and nice to their mothers, HFCs are massively powerful greenhouse gases - in some cases thousands of times more powerful than carbon dioxide. A kilo (about a bag of sugar) of the most commonly used HFC does as much warming as about a tonne and a half of CO2.

To date, nobody's got to grips with the f-gas situation, which is a problem, because although they're nowhere near carbon dioxide emissions in term of causing climate change, they do play a significant role.

One of the major users of f-gases as refrigerants are supermarkets. In the UK, f-gases in supermarket refrigerators have more global warming impact than the supermarket distribution fleet - all those lorries trundling along motorways. So Sainsbury's announcing a timetabled phase-out of f-gases in their refrigerant units is the equivalent of them cutting their distribution emissions entirely. For Greenpeace it marks a big step forward in a campaign that's now 15 years old.

In a happily ironic twist they're going to replace the f-gases with carbon dioxide, which although also a greenhouse gas, will in this particular and quite specialised case be thousands of times less problematic for the climate. And this is going to be a big change - the company estimates that this one measure will cut their carbon-equivalent footprint by 30%.

Sainsbury's are leading on this, and that's great. For all that we occasionally moan on about corporations, in this case they're putting politicians, who have singularly failed to get on with sorting out the problems posed by these dangerous gases, in the shade. We now expect other supermarkets around the world to follow suit - and if the global retailing sector can make a shift away from f-gases, that's going to be a significant cut in global emissions.

And I guess it just goes to show that the nature of environmental challenges shifts over time. Back when we were clearing up CFCs the fact that HFCs were powerful greenhouse gases didn't make it onto anyone's radar. And I guess, in my reflective Monday morning mood, that might suggest a slightly more thoughtful approach to how we manage our interaction with the planet.