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
Per stirpes Per stirpes Per stirpes (; "by branch") is a legal term from Latin. An estate of a decedent is distributed "per stirpes" if each "branch" of the family is to receive an equal share of an estate. When the heir in the first generation of a branch predeceased the decedent, the share that would have been given to the heir would be distributed among the heir's issue in equal shares. It may also be known as strict per stirpes or the old English approach, and differs from distribution "per capita", as members of the same generation may inherit different amounts.