Mass extinctions have occurred with much greater regularity than every 250 million years. The ice ages come in pulses, to use the geological term, and both the

Mass extinctions have occurred with much greater regularity than every 250 million years. The ice ages come in pulses, to use the geological term, and both the warming and cooling trends have inflicted vast changes in the species inhabiting the planet. As far as CO2 emissions, the EPA's own statistics suggest a static-to-downward trend since the early 2000s in the U.S. (http://www.epa.gov/climatechange/ghgemissions/gases/co2.html http://www.epa.gov/climatechange/ghgemissions/gases/co2.html). We're barely above where we were in 1990, despite an increase in population from 250 million in 1990 to 319 million today. 3rd World economies will eventually follow suit, as they adopt the cheap new green tech that we're getting. The trend today is toward more efficient vehicles, cheaper and more available solar for houses, a massive switch in electric power plants from coal and oil to inexpensive natural gas which emits less carbon. Technology, Chinese mass production of green energy products like solar panels, American fracking of natural gas, all will conspire to reduce the carbon emissions. The trends are heartening.