A． Clear solutions already exist for reducing greenhouse gas emissions． B． Despite this， how our dietary choices affect climate change is often underestimated． C． Food， especially livestock， also lakes up a lot of room D． In developed countries， vegetarianism would bring all sorts of environmental and health benefits． E． No matter how much their carnivorous friends might deny it， vegetarians have a point： cutting out meat delivers multiple benefits． F． Though a relatively small increase in agricultural land， this would more than make up for the loss of meat．

W    hat would happen if the world suddenly went vegetarian？

   People become vegetarians for a variety of reasons． Some do it to make animal suffering， others because they want to pursue a healthier lifestyle． Still others are fans of sustainability or wish to reduce greenhouse gas emissions． （1） 　　And the more who make the switch， the more those perks would manifest on a global scale．

   Jarvis and other experts at Colombia's International Centre for Tropical Agriculture carried out researches to see what might happen if meat dropped off the planet's menu overnight．

   First they examined climate change． Food production accounts for one﹣quarter to one﹣third of all greenhouse gas emissions from human activities worldwide， and the worst of responsibility for those numbers falls to the livestock industry． （2） 　 　In the US， for example， an average family of four emits more greenhouse gases because of the meat they eat than from driving two cars but it is cars， not steaks， that regularly come up in discussions about global warming．

   （3） 　　Of the world's approximately 12 billion acres of agricultural land， 68% is used for livestock． Should we all go vegetarian， ideally we would give at least 80% of that pastureland （牧场） to the restoration of grasslands and forests， which would capture carbon and further alleviate climate change．

   The remaining 10 to 20% of former pastureland could be used for growing more crops to fill gaps in the food supply．（4） 　　That's because one﹣third of the land currently used for crops is dedicated to producing food for livestock not for humans．