So, over an average lifetime, one American will emit roughly 2000 mt.
However, having a child changes everything. According to a new paper in Global Environmental Change,
Under current conditions in the United States, for example, each child adds about 9441 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.This is interesting but not, of course, a reason not to have children (though I'm sure some skeptic will twist it in that way.) Humans aren't going to solve global warming by deciding not to have children. Sure, we could use less reproduction, but obviously we can't do without it and the solution we're looking for involves technological change and not living in mud huts without children. But it's something to think about.