Cows, sheep and goats contribute greatly to climate gas emissions. Partly because their digestion produces the strong climate gas methane. Partly because the food they eat adds to deforestation and typically requires fossil fuels.
Three quarter vegetarian is what you can call someone who eats meat half as much and half as often as before. A vegetarian diet gives climate, environmental and health benefits. 75% of these benefits can be obtained by eating half as much meat half as often. That makes a big difference.