Human population and carbon dioxide

A recently proposed model of human population and carbon utilization is reviewed. Depending on parameter values, one of three possible long-term outcomes is obtained. (1) Atmospheric carbon, (CO2)atm, and human populations equilibrate at positive values. (2) The human population stabilizes, while (CO2)atm increases without bound. (3) The human population goes extinct and atmospheric carbon declines to 0. The final possibility is qualitatively compatible with both “consensus” views of climate change and the opinions of those who are more impressed with the manifestly adverse consequences of carbon-mitigation to human reproduction and survival.