There are two good reasons for eating more fruit and vegetables in place of meat: it’s better for you and it’s better for the environment.

Where the food you eat comes from matters less than what it is. The greenhouse emissions from transporting food are typically only a tiny proportion of the total emissions associated with growing food.

Livestock are responsible for nearly a fifth of all greenhouse emissions, from the methane produced by their guts and manure, to nitrous oxide emissions from the fertilisers used to grow feed for them. Because it takes several kilograms of plant matter to grow a kilogram of meat, producing meat and animal products such as cheese usually greatly multiplies the environmental damage done by farming. The huge amounts of land required are driving the destruction of rainforests, for instance. Even small reductions in consumption, such as making Mondays meat-free, could make a big difference.

If you do eat meat, choose it carefully. Cud-chewing animals such as cattle and sheep are the worst offenders and, surprisingly, grass-fed cattle generally produce even more emissions than grain-fed ones, according to as-yet-unpublished work by Nathan Pelletier of Dalhousie University in Halifax, Canada. Opt instead for chicken, pork or, if you live in Australia, kangaroos.

In the US and UK, eating venison could actually reduce emissions where it helps curb burgeoning wild deer populations. And feel free to feast on alien species taking over your neighbourhood, such as the grey squirrels taking over the UK and the Louisiana crayfish invading Arizona.