I = PAT that human population may stabilize at around 11.2 billion in 2100, the I=PAT equation will continue to be relevant for the increasing human impact on the environment in the short to mid-term future. Increased population increases humans' environmental impact in many ways, which include but are not limited to: The variable A, in the I=PAT equation stands for affluence. It represents the average consumption of each person in the population. As the consumption of each person increases, the total environmental impact increases as well. A common proxy for measuring consumption is through GDP per capita. While GDP per capita measures
An Essay on the Principle of Population Malthus's conclusions. He notes that despite the predictions of Malthus and of the Neo-Malthusians, massive geometric population growth in the 20th century did not result in a Malthusian catastrophe. Many factors have been identified as having contributed: general improvements in farming methods (industrial agriculture), mechanization of work (tractors), the introduction of high-yield varieties of wheat and other plants (Green Revolution), the use of pesticides to control crop pests. Each played a role. The enviro-sceptic Bjørn Lomborg presented data to argue the case that the environment had actually improved, and that calories produced per day per capita globally went up 23%