Eating to cool the planet
Every year or so you can count on a major report linking what we put on our plate to climate change. Last year the Changing Climate, Changing Diets report from the British think tank Chatham House warned that eating less meat is critical for keeping the global temperature rise under control. This year it was a study from Oxford University saying that if we just stuck to the basic dietary guidelines of eating smaller amounts of meat and more veg we'd shrink food-related greenhouse gas emissions by a third - not to mention save a few million lives along the way thanks to healthier eating.
But is anyone listening?
Debunking the myths and misinformation surrounding climate change is an important field for scientists, who must be careful not to reinforce the myths.
We might get the link between climate change and burning fossil fuels and even try to limit our use with solar panels and smaller cars, but there's less awareness that our food choices are also influencing climate change - and that by tweaking our diet we can make a difference.
So where do you start?
Eat less red meat.
This is top of the list because cattle and sheep both generate so much greenhouse gas, explains Professor David Griggs of Monash University's Sustainability Institute.
"To produce one kilo of protein from beef generates the greenhouse gas equivalent of 300 kilos of carbon dioxide, according to the Food and Agriculture Organisation of the UN," he says. "By comparison cow's milk, chicken and pork produce less - the greenhouse gas equivalent of below 100 kilos of carbon dioxide. But eating less animal food isn't only good for the environment - we'd also reduce the costs to the health system because there would be benefits for our health."
It's also important to look at how the food you buy is produced - the more processing, packaging and transport involved the more it contributes to greenhouse gas emissions, Griggs points out.
"A lettuce grown in a greenhouse and then transported around the world under refrigeration might produce more emissions than a steak," he says. "We need to be conscious of food miles and buy food that's in season and grown as close to home as possible - and which comes with little or no packaging."
In other words a locally grown apple beats a packet of chips.
A bowl of soup made with (locally grown) French lentils trumps beef stew too. When it comes to reducing greenhouse gases, legumes are a star. Producing a kilo of legumes emits the equivalent of 0.5kg of Co2, while producing a kilo of beef generates the equivalent of 9.5 kilos of Co2 according to the Global Pulse Confederation.
There's a word for this climate conscious way of eating - a 'Climatarian' diet, a word that Mark Pershin, founder of Less Meat Less Heat wants us to hear more of.
Less Meat Less Heat is a campaign to help tackle climate change by getting us to eat a greener diet.
"We need to get on top of climate change and to do that we need to start a movement. It's not necessarily about avoiding red meat altogether - some people might switch to kangaroo instead of beef or lamb or order a chicken parmigiana instead of steak - and save beef or lamb for special occasions," he says.
LMLH has now raised enough money via crowdfunding to produce a free app - the Climatarian Challenge - due to launch in July and free to download from the Google Play Apple iOS app stores. It's designed to help users join the dots between what they choose to eat and its contribution to climate change.
"It's a month long challenge. You'll start off with 4000 carbon points - the equivalent of 40 kilos of carbon emissions - this is your carbon budget for the month and compatible with keeping climate change to below 2 degrees. The aim is to use up no more than those points," Pershin explains. "The higher the carbon footprint of a food, the more points you'll use up - beef and lamb will use them up quickly but low carbon meals based on chicken or legumes for instance make it easier to keep within the budget."
To drive home the message that reducing meat is crucial to controlling global warming, Pershin cites two scenarios developed by Britain's Chatham House.
"The 'high meat' scenario calculates what would happen to the planet's temperature if we went all out to curb climate change in other ways - except reducing meat consumption and concludes that the mean temperature would still rise past 4 degrees Celsius because Asian countries are increasingly adopting a more Western style diet.
"On the other hand, if we were to take no action other than to reduce our red meat intake to 65g per week we could limit global warming to less than 2 degrees."