Some people claim that eating less meat, or becoming vegetarian, is the best thing individuals can do for the environment. I agree that reducing meat consumption is highly beneficial, but I would not say it is the only or necessarily the best action.
The environmental case against meat is strong. Livestock farming produces a considerable share of global greenhouse gases, mainly because cattle release methane, and it uses vast amounts of land and water. Large areas of forest, such as the Amazon, have been cleared to create pasture or to grow animal feed. A plant-based diet needs far fewer resources, since crops can be eaten directly by people instead of being fed to animals first. There are health benefits too, as diets rich in vegetables and pulses are linked to lower rates of heart disease.
Even so, I believe other actions can have a larger impact. Transport and energy production are responsible for a greater share of emissions than agriculture, so using public transport, insulating homes and switching to renewable power are very effective. In addition, diet is closely linked to nutrition and culture. In some regions, such as Mongolia or parts of the Arctic, meat and dairy are essential sources of nutrients and have been central to life for centuries, and millions of people in farming communities depend on livestock for their income. A global move to vegetarianism would be impractical and could harm these groups.
A more realistic approach is moderation. If people in wealthy countries ate meat less often and chose sustainable sources, the effect on the climate would be significant without causing hardship elsewhere.
In conclusion, eating less meat is an important contribution, but it works best alongside changes in energy and transport rather than as a single solution.