Key to predicting future climate: Look back millions of years

An international team of climate scientists, including two from the University of Michigan, suggests that researchers using numerical models to predict future climate change should include simulations of past climates when evaluating model performance. "We urge the climate model developer community to pay attention to the past and actively involve it in predicting the future,” said Jessica Tierney, the paper's lead author and an associate professor in the University of Arizona's Department of Geosciences. "If your model can simulate past climates accurately, it likely will do a much better job at getting future scenarios right. As more and better information becomes available about climates in Earth's distant history, reaching back many millions of years before humans existed, past climates become increasingly relevant for improving our understanding of how key elements of the climate system are affected by greenhouse gas levels, according to the study published Nov. Unlike historic climate records, which typically only go back a century or two-a mere blink of an eye in the planet's climate history-paleoclimates cover a vastly broader range of climatic conditions that can inform climate models in ways historic data cannot. These periods in Earth's past span a large range of temperatures, precipitation patterns and ice sheet distribution. "Looking to the past to inform the future could help narrow uncertainties surrounding projections of changes in temperature, ice sheets, and the water cycle,” Tierney said.