Medieval Climatic Anomaly in the Americas

摘要: Discussions of future climate, whether in forums science or policy, have come to be dominated by the debate over human-induced global warming. Typically, these discussions focus on temperature departures that might result from continued anthropogenic emission greenhouse gasses; response earth’s physical and biotic systems those departures; socio-economic impacts responses. Strong differences opinion fuel discussions. Many scientists, citing computerized simulations an atmosphere with increased heat-trapping capacity, conclude significant warming is likely future, perhaps already underway. Others, stressing uncertainties computer models questioning assumptions which are based, proclaim predictions premature, unscientific, alarmist. The socio-economics no less polarized. One side warns failure curtail fossil-fuel emissions could threaten food water supply Earth’s burgeoning human population; other raises specter restricting fossil consumption lead economic collapse.