In "Reproduction and the Carbon Legacies of Individuals," two scientists say:
Much attention has been paid to the ways that people’s home energy use, travel, food choices and other routine activities affect their emissions of carbon dioxide and, ultimately, their contributions to global warming. However, the reproductive choices of an individual are rarely incorporated into calculations of his personal impact on the environment.So, I know that the Julian Simon folks ("people, the ultimate resource") may claim that we need kids to make the world a better place, but do we need ALL of them?
Here we estimate the extra emissions of fossil carbon dioxide that an average individual causes when he or she chooses to have children. The summed emissions of a person’s descendants, weighted by their relatedness to him, may far exceed the lifetime emissions produced by the original parent.
Under current conditions in the United States, for example, each child adds about 9,441 metric tons of carbon dioxide to the carbon legacy of an average female, which is 5.7 times her lifetime emissions. A person’s reproductive choices must be considered along with his day-to-day activities when assessing his ultimate impact on the global environment.
Note that these statistics are based on American kids -- not kids elsewhere in the world. Perhaps this is another offshoring opportunity: Have your kids here but raise them in the developing world -- where they are likely to live a simpler (lower carbon) lifestyle.
I guess the "god says procreate" folks (in Rome, SLC, Mecca, Jerusalem, Benares, etc.) should be buying a BUNCH of carbon permits!
Bottom Line: Have your kids, but remember that they create both positive AND negative externalities.