Morrisons has been criticised by the Environment Agency for its decision to switch from plastic to paper bags for fruit and vegetables, on the grounds that paper bags have a larger carbon footprint.

Whoever expected that sustainability would be simple? For two centuries innovation, ingenuity and investment have been entirely focused on the half of the supply chain which transforms natural resources into consumable goods. That part has become optimised and efficient. But the phrase ”the last mile” indicates where our attention stops. The second half of the supply chain, after the last mile, is the route by which material and energy get dumped back into the planet’s environment, usually as quickly and thoughtlessly as possible. This has been known as “waste” – by definition waste is something which has no value and receives no interest.

We have deep information and knowledge about how we efficiently go from raw materials to consumable goods, but almost none on what happens next.

It is hardly surprising that as we begin to recognise the limited capacity of the planet to absorb landfill and oceanic and atmospheric pollution, we are only now realising how poorly we understand it. “Waste” may also describe the consequences of habitat destruction and the living waste of extinct species, or of the waste of the health, livelihoods, communities and cultures of people producing our goods in unsustainable production cycles. We recognise that we have reached the anthropocene era – the ability to undertake planet-scale engineering – but we have almost no tools or measures to understand the effects.

Even the Environment Agency is relying for its critique on one study published seven years ago.

The issues are, unsurprisingly, complex. Yes, paper bags have greater climate impact, but they biodegrade much faster. Meanwhile plastic packaging can protect food from damage and prolong its life, thereby saving energy and avoiding landfill which leaches greenhouse gases. Buying British produce minimises air miles, but may have involved extra consumption of energy in heated polytunnels. Organic fruit and veg is often, ironically, more heavily packaged than conventional alternatives, to avoid any risk of muddling them up on the shelf.

Any company which treads into this area may feel it is entering a minefield of competing objectives, where its efforts only open it to criticism. Consumers may feel “why bother?"

We need bodies like the Environment Agency not to criticise, but to recognise companies’ intentions and efforts and to help guide and encourage them. Perfection should not be the enemy of the good. These bodies could also play a role in facilitating collaboration and knowledge-sharing: the issues are so large-scale and complex that no single company can master then alone, and yet fears of competition regulation prevent companies from pooling and sharing their efforts.

Of course “social responsibility” is full of virtue signalling, and of claims which are greenwashed and fake. But genuine efforts, even small ones, should be encouraged and built on, not sniped at.