Global Food Security And It's Impact The current population of the world is approximately 7 billion. Of this number, 2 billion are underweight and 1 billion are hungry. At the same time, 2 billion adults and children are overweight and 1 billion are considered "obese". We have enough land globally to grow enough cereal crops to sustain the current world population. But if it keeps growing we will run out of room to grow even that much. While developing continents like Asia grow richer, they are able to afford to eat more meat and dairy products. The more of this they wish to consume, the more livestock we must produce. Land space for these animals is also running out. They also produce methane, which is just as dangerous a greenhouse gas as carbon dioxide, if not moreso. Some people suggest cutting down forests to grow more pastureland for production species (cattle, sheep etc). This will increase the amount of carbon dioxide in the atmosphere as well as stripping native species of their natural habitat. By doing this, we may inadvertently kill off species that call forests home, destroying the biodiversity of the area and the local ecosystem. This will lead to more extinct species, some of which help to clean up the mess we leave behind. Another issue of increasing amounts of production animals is the waste. Already, nitrogen that leaches out of muck heaps into water systems causes weeds to thrive as they use the nitrogen to grow unusually fast, making the waterways impossible for other species to inhabit. This phenomenon is known as "algal bloom", and contributes to lowering biodiversity in our lakes and rivers. Just some of the facts on the state of the world I've learned this year at university.