A recently released study brought sobering news about the future effects of climate change, predicting they could be twice as bad as current models have projected under a “business-as-usual” scenario—and then some. Even if the world hits its 2 degree Celsius target, the paper—which appeared in the journal Nature Geoscience—warned that sea levels could rise six meters or more, large areas of the polar ice caps could collapse, the Sahara Desert could become green, and tropical forest borders could produce fire-dominated savanna.
To obtain their findings, the researchers studied three well-documented historical warm periods: the Holocene thermal maximum, some 5,000–9,000 years ago, the last interglacial, 129,000–116,000 years ago, which were both caused by predictable changes in the Earth’s orbit; and the mid-Pliocene warm period, 3.3–3 million years ago, when atmospheric concentrations of carbon dioxide were similar to what they are today. Two of the study’s co-authors, Katrin Meissner, director of the University of New South Wales Climate Change Research Centre, and Alan C. Mix, distinguished professor of earth, ocean, and atmospheric sciences at Oregon State University, recently spoke with Nexus Media about the study, which was conducted by an international team of researchers from 17 countries. This interview has been edited for length and clarity.