"Cutting back on beefburgers and bacon could wipe $20 trillion off the cost of fighting climate change. That's the dramatic conclusion of a study that totted up the economic costs of modern meat-heavy diets.

The researchers involved say that reducing our intake of beef and pork would lead to the creation of a huge new carbon sink, as vegetation would thrive on unused farmland.

The model takes into account farmland that is used to grow extra food to make up for the lost meat, but that requires less area, so some will be abandoned. Millions of tonnes of methane, a potent greenhouse gas, would also be saved every year due to reduced emissions from farms.

These impacts would lessen the need for expensive carbon-saving technologies, such as "clean coal" power plants, and so save huge sums, say Elke Stehfest of the Netherlands Environmental Assessment Agency and colleagues."