One burger, hold the carbon

Fast food is bad for us – and even worse for the planet. While chains are trying to make their meals ethical, they could do more, argues Sophie Morris

Making your diet greener at home isn't difficult. Earnest eco wonks may try to flummox you with talk of food miles, intensive farming and embedded carbon, but basically, as long as you balance your purchases across produce that is seasonal, local or organic, you're making the right moves. If you really want those green beans from Kenya in the bleakest moments of midwinter, don't beat yourself up about it – you're supporting an important cog in Kenya's economy.

Eating out is much trickier, especially when short of time. On average, British workers take 35 minutes for lunch, which means one thing: fast food. Over the past decade, speedy lunch outlets have expanded to include plenty of healthy soup/salad/sandwich options, but healthy doesn't mean green.

And if you eat meat, doing the right thing by the environment is harder still. The truth is, giving up meat is the single most effective way you can reduce the impact your lifestyle has on the planet, hence all the chat about meat-free Mondays. Meat production contributes more emissions to the dizzying global tally than transport. The answer is to cut back, or simply cut it out.

Otarian, a carbon-conscious vegetarian fast-food chain, hopes it can nudge consumers towards environmentally sound meal choices, avoiding the lentil and mung bean route. It launched in New York in April and will open two branches in London this summer, with more planned. Its premise is simple: cutting back on meat fights carbon emissions, deforestation, water pollution, land degradation, unfair trade and obesity. But there's a gimmick. Otarian displays the carbon footprint of every item on the packaging, alongside the carbon which would have been emitted had you gone for a similar meal including meat. A veggie burger (pictured above) for example, has a carbon footprint of 1.72kg, compared to 2.55kg for its meat equivalent. The coconut curry comes in at just 1.62kg, compared to the 3.52kg a chicken curry would be guilty of. The conceit becomes harder to maintain with desserts. The berry pannacotta compared with a chocolate cheesecake – not, in my book, an equivalent – but egg-free chocolate cake and chocolate mousse are also on the menu.

Still, the Otarian vision is impressive: no air freighting, more than 95 per cent of the restaurant waste will be recycled, composted or recovered. All dishes are egg-free, which emphasises an issue even the most conscientious of British consumers still struggle with: the term "free range" means very little in itself, only that the laying hens have access to an outdoor area. Unfortunately, unless you find a farm with high welfare standards, "free range" is often little more than lip service. Otarian milk is not homogenised and only lightly pasteurised, and comes from a low-yield farm that aims to give its animals as long a life as possible rather than milking them to death.

This attention to detail is noble, pious even, so it's a pity that founder Radhika Oswal, one of the world's richest women, owes part of her wealth to her family's investment in Burrup Fertilisers, a massive producer of liquid ammonium, a deadly pollutant.

It's as well her pockets are deep, as attempting to make amends via Otarian comes at a considerable cost, but at £7.25 for a burger and £6.45 for a spinach and potato tart, customers will not be unduly punished for their good deed.

This, though, depends on whether you want a lecture with your lunch. Carbon footprinting your meal might come in handy for conscientious eaters, but not everyone wants to be nagged on their lunchbreak.

But the menu sets a lot of precedents, and prices like these makes one wonder what the rest of our favourite food chains are spending their money on. Unsurprisingly, a number of them are reluctant to divulge where their sourcing policies, Nandos, Pizza Express, Wagamamas and Eat among them. Lunchtime sandwich favourite M&S has commendable sourcing policies for its meat, fish and egg products. Pret A Manger and Itsu come out well too. Itsu's salmon is farmed, but it uses top grade farmed fish. The pole and line-caught yellowfin tuna is approved by Friends of the Sea, but while not yet endangered, yellowfin tuna is still overfished.

Pret a Manger stopped selling tuna sandwiches after The End of the Line film exposed the desperate state overfishing has left our oceans in, but still sells pole and line-caught skipjack in baguettes. Yellowfin has been dropped, the fresh salmon is wild, the smoked is farmed, the cattle and pigs enjoy high welfare standards, the chicken and eggs are free range. Pret gives away left-over sandwiches to those in need at the end of the day and has impressive policies on other green issues.

The details of the sourcing policies for eco fish and meat is complicated. Otarian makes the point that it could be easier to avoid meat altogether – yet more food for thought.