The scientists found that beef was the worst meat for environmental impact, causing 25 times more nitrogen pollution per unit of food protein than cereals.

Climate change and nitrogen pollution are also said to be contributing factors.

They found that the changes set in at much lower rates of nitrogen pollution than thought.

Controlling the usage of nitrogen enhancing fertilizer and reducing the amount of nitrogen pollution into the air can both lower inhibition of methane oxidationa major sink of atmospheric methane.