Lettuce 'three times worse than bacon' for the environment, scientists claim
Greenhouse gas emissions from lettuce production are three times higher per calorie than from bacon, study finds
Published 16/12/2015 | 15:07
Eating lettuce could be three times worse for the environment than bacon, scientists have claimed.
Despite calls from celebrities including Arnold Schwarzenegger and Sir Paul McCartney for people to eat less meat to help save the planet, new research suggests that ‘healthier’ diets with more fruit and vegetables could actually be worse for global warming.
The study, by scientists at Carnegie Mellon University, compared the greenhouse gas emissions from the production of 1,000 calories of different foods.
“Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon,” Professor Paul Fischbeck, one of the report’s authors, concluded.
Lettuce is so low in calories that someone would need to eat at least two whole iceberg lettuces to get close to the calorie intake of two rashers of smoked back bacon.
As a result, the emissions from transporting bulky lettuces are far higher per calorie than those from pork.
Lettuce is also far more likely to perish before it reaches the dinner table, with the food waste further increasing its emissions footprint.
Other vegetables fared far better than lettuce, with cabbage producing a fifth of the emissions of pork per calorie, and broccoli producing less than half the emissions.
Beef and lamb produce far more emissions than pork or chicken, and beef is still worse than lettuce for emissions, Prof Fischbeck said.
However, the study found that switching to the balanced diet recommended by US health officials – including more fruit, vegetables, dairy products and seafood – produced six per cent more greenhouse gas emissions overall than a typical American’s current meat-rich diet.
Antony Froggatt, senior research fellow at Chatham House, which recently recommended a meat tax to help tackle global warming, said: “The study confirms that meat, poultry and egg food groups as a whole are relatively high sources of greenhouse gases compared to vegetable, grains, pulses and sugars.
“Therefore reducing consumption of the former food groups, which is also recommended from a health perspective, in this, and other studies, can be an important opportunity of greenhouse gas emissions savings.”
The livestock sector accounts for about 15 per cent of global greenhouse emissions – the same proportion as direct emissions from cars, planes, trains and ships combined.