According to projections by the United Nations, the world population has reached 7 billion and continues to grow rapidly. While more people are living longer and healthier lives, gaps are widening between the rich and the poor in some nations and tens of millions of people are vulnerable to food and water shortages. There is, of course, the issue of the impact of that sheer number on the environment, including pollution, waste disposal, use of natural resources and food production. This post focuses on wheat and the effect of our numbers on the environment. Wheat is the most important cereal in the world and along with rice and corn accounts for about 73 percent of all cereal production. It isn't surprising that 7 billion people have a lasting impact on our world's natural resources and the environment in which we live. Gasoline prices at a station near Lindbergh Field as a plane approaches landing in San Diego, California, in 2008. One of the world's breadbaskets lies in the prairies of Canada. This stalk, near Lethbridge, Alberta, helps form the foundation for the most important food product in the world: cereal grains. A worker removes dead fish from a lake in Wuhan, central China's Hubei province, in 2007. Mankind's immense pressure on the planet is causing the fastest extinction of species in millions of years and is rapidly heating up the planet, threatening more extreme weather, according to scientists.