Study: Massive Abrupt Warming During Past Low-CO₂ Era

A new pollen-based reconstruction study shows Greenland warmed 10–16°C within decades during 11 Dansgaard–Oeschger events between 57,000 and 29,000 years ago, when atmospheric CO₂ was near 200 ppm. These globally expressed, circulation-driven shifts demonstrate that rapid, large climate changes occurred naturally under low and relatively stable carbon dioxide levels.