New research led by the University of Washington has shed light on the potential impact of rising carbon dioxide levels on global warming. The study, published in Science Advances, delves into the relationship between CO2 and climate sensitivity, providing valuable insights into future temperature projections.

The research focuses on the analysis of the most recent ice age, when a significant portion of North America was covered in ice. By examining this period, scientists have been able to refine their understanding of how CO2 levels influence global temperatures.

According to lead author Vince Cooper, a doctoral student in atmospheric sciences at the University of Washington, the study aims to narrow the estimate of climate sensitivity. By studying the cooling effects of lower greenhouse gas levels during the ice age, researchers can better predict the extent of future warming with higher CO2 concentrations.

While the study confirms existing estimates for best-case and most likely warming scenarios from doubling CO2 levels, it also offers a more optimistic outlook by reducing the worst-case scenario. Previously projected at a 5-degree Celsius increase, the worst-case scenario now stands at 4 degrees Celsius for a doubling of CO2.

Currently, CO2 levels are at 425 parts per million, approximately 1.5 times higher than preindustrial levels. Without significant emissions reductions, CO2 levels are on track to double before the end of the century.

The authors caution against using recent decades as a reliable indicator of future climate trends under global warming. They emphasize the importance of considering longer-term climate cycles and patterns in projecting the impact of rising CO2 levels on Earth’s climate.