The carbon footprint of a vegetarian is half that of a meat eater, but it’s not all bad news for carnivores

Instead of the steaks and pork chops in our fridges, should we be investing in clean, green protein? Well, yes. Methane from livestock is responsible for 14% of global warming, and the gas is 25 times more potent than CO 2 . The more meat and dairy you eat from ruminants, particularly cows, the more burping and farting you are responsible for. The 2014 documentary Cowspiracy focuses on the idea that this is the great neglected greenhouse gas source.

By 2050, experts predict, the demand for meat will have doubled, and meat-related emissions will boom at 12bn tonnes of carbon to feed a population of 9 billion. Our consumption has to tail off if we are to achieve Paris emissions goals.

In 2013 researchers found the carbon footprint of a vegetarian to be half that of a meat eater. Comfortingly, they also found that a flexitarian approach is a close second. By replacing three-quarters of our ruminant budget with other forms of protein, we could reduce livestock emissions to 3.1bn tonnes by 2050. Chicken could play a part, but some non-meat proteins should be included, too.

Not all animals are equal, ethically. Cows raised on species-rich pasture produce fewer emissions. But industrialised agriculture focuses on how to raise animals indoors in feedlots more efficiently. Low-emissions meat could have a big ethical impact in other ways.

Do food retailers have a responsibility to sell less? Riverford’s “How Much Meat” campaign explores this idea. Riverford sells vegetables, so it has a vested interest, but it also sells organic meat. Apparently founder Guy Watson launched the campaign after his daughter, having seen Cowspiracy, petitioned him to divest from the livestock industry.

The big picture: the fungus among us



Facebook Twitter Pinterest Small wonder: a rare image of the obscure Marasmius haematocephali mushroom. Photograph: Steve Axford

Fungi are known as nature’s ultimate recycler, but it is time to acknowledge the radical diversity and downright beauty of fungi, slime moulds and lichens. Botanist photographer and fungi-obsessive Steve Axford, a native of New South Wales, Australia, is on a mission to take pictures of the most obscure specimens to be found on the planet, many of which have never been catalogued before.

Well dressed: Pembe Club



Facebook Twitter Pinterest All that glisters: Yasmine Haji’s designs use natural, sustainable materials including recycled glass and East African coins.

Diamonds aren’t our best friends, ethically speaking, which is why I love the way the best new jewellery brands are redefining which materials really are precious. Pembe Club is a recent member of this club. Yasmine Haji, a third-generation jewellery designer, sources natural, sustainable materials from Tanzania including wild grass seeds, recycled glass, East African coins, harita, ostrich eggs and cowrie shells alongside recycled glass beads, pyrite and black onyx. Her mission is to make sure that the materials are readily available to the local artisans and villagers she works with – and to convince them as well as buyers that these materials can replace ivory. Elephant poaching plagues Tanzania. Haji is determined that by replicating shapes and techniques in sustainable materials she can make a positive change to this desperate situation. (pembeclub.com)

Email Lucy at lucy.siegle@observer.co.uk or follow her on Twitter @lucysiegle