A new study confirms what many vegetarians and vegans have always known -- they're helping save the world, one bite at a time.
A model published in scientific journal Nature Communications has revealed a plan for the survival of humanity and, spoiler alert, it doesn't include pies.
The study, carried out by the Institute of Social Ecology in Austria, explains that it may be possible to feed future populations sustainably -- that is, without converting any more of the world's forests to croplands.
The answer is dietary choices: the study says humans need to dramatically change what we eat if we want to live in a world that has trees in it.
That means no more burgers, more falafel.
Scientists modelled the supply and demand of agriculture biomass under 500 different future scenarios -- varying according to yield, crops and dietary choices -- to find scenarios that were viable without converting more of the world's forestry land into agricultural land.
They found that if everyone in the world became vegan, 100 percent of these scenarios would be viable in 2050 and we could keep the world's existing forestry.
They would be feasible, the study says, "if cropland yields rose massively and cropland expanded strongly into areas that are today used for grazing [livestock].
"Vegetarian or vegan diets are less often restricted by cropland availability or limits on the biomass supply of grazing land."
Ninety-four percent of the scenarios would be possible if the world became vegetarian.
But only 15 percent would be possible if a rich, meat-based diet was adopted by all.
Now that's some food for thought.