The problem is not the amount of people but how much each individual consumes. Getting meat out of your diet is a simple and a small sacrifice. Besides the health benefits there is also the fact that you don’t contribute to the culling of 70 billion animals per year (of which 40% is probably not eaten and thrown in the trash). Not only that but you don’t contribute to the greatest cause of deforestation, antibiotics resistance, decline of biodiversity, water waste, …

Besides the global population is steadily stagnating (Africa is still booming) as a lot of countries see population decline (less than 2 children per woman).