Greenhouse gases in the atmosphere ( carbon dioxide, methane, nitrous oxide, water vapor, etc) act to slow down the escape of heat radiating from the Earth's surface. Atmospheric greenhouse gases are increasing. The resulting average international temperature increases are marked by upward shifts in world wide weather patterns. When Milankovitch cycles, climatic patterns on Earth brought about by "orbital forcing", do finally begin to push towards naturally occurring global warming trends, these cycles will be amplified by our unnatural levels of greenhouse gases. Even if we had stopped releasing them yesterday, these gases will remain for millennia. At the ever increasing rates of the release of these gases, how much will our descendants suffer because of us? How much does any other issue even compare to this one? How long before we do enough about the real inconvenient truth causing global warming: human overpopulation.