"Why not eat insects?" asked American pamphleteer Vincent Holt in 1885, proof that selling the idea of insect-eating to meat'n'two veg culture is nothing new.

There are already 2 billion people worldwide who routinely eat bugs, but entomophagy is having a foodie moment in the western world. Insects are even a novelty on the UK food scene. They're mainly found as subversive garnishes for salads or cocktails, or on the menus of experimental pop-up restaurants. One start-up company (eat-ento.co.uk) is focusing on the aesthetic issue, however, and hopes to remove our psychological barrier to insect-eating by transforming the flesh of edible creepy crawlies into anodyne cubes.

The eco virtues of entomophagy are really tasty. Bugs have a much smaller carbon footprint than livestock. Few insect species produce methane, and they provide dietary protein very efficiently – 10kg of feed produces 1kg of beef, but just 1.7kg of feed produces 1kg of crickets (a cricket is 70% protein by weight and can be ground into protein-rich flours). According to a UN report insects could help plug the looming protein gap in our diet, given that by 2050 a world population of 9 billion will require food production to increase by 70%. As 70% of the world's agricultural land is engaged with unsustainable meat production, this leaves a huge deficit. Insect harvest could also provide economic bounty to forest communities and hotspots of insect biodiversity.

There are 10 quintillion insects alive at any time, but entomologists and ecologists worry about our tendency to overharvest species, leading to colony collapse. Insect farming might be a solution, and the first edible-insect farm in the US is now producing crickets in Ohio.

In reality, western insect use in human food production is likely to be via livestock feed – meal can be made from the larvae and pupae of flies and mealworms. The idea is that you eat a cow that has been fed on insects.

I take your point that we've yet to find oven-ready mealworms (taste like caramelised onions, apparently) in our supermarkets, but edible insect products are in development. You want crickets? Go to Kickstarter: the company Six Foods is looking for funds to produce Chirps, a crisp/cricket hybrid.

Green crush: Ben Howard

Some celebrated citizens are given the keys to a city, but double Brit-winning folk singer Ben Howard has made it on to the banknotes of his Devon hometown. Totnes is a passionately alternative town with a community currency designed to stimulate the local economy and decrease dependency on the wider oil economy. His tenner joins a new £5 and £21 note featuring Charles Babbage (inventor of the computer) and novelist Mary Wesley. But their days could be numbered: the town is now working on a paperless mobile-phone currency.

Greenspeak: Face wash veto {feis/ wā∫ vi:to} noun

After it was discovered that the Great Lakes were riddled with microbeads – the microscopic synthetic plastic beads in cosmetics – Illinois legislators had them outlawed. Cleaner water if not cleaner pores

If you have an ethical dilemma, email Lucy at lucy.siegle@observer.co.uk