Accurate climate models

The most accurate climate change models predict the most alarming consequences, the Washington Post reports.

The climate change simulations that best capture current planetary conditions are also the ones that predict the most dire levels of human-driven warming, according to a statistical study released in the journal Nature.

The study, by the Carnegie Institution for Science in Stanford, Calif., examined the high-powered climate change simulations, or “models,” that researchers use to project the future of the planet based on the physical equations that govern the behaviour of the atmosphere and oceans.

The researchers then looked at what the models that best captured current conditions high in the atmosphere predicted was coming. Those models generally predicted a higher level of warming than models that did not capture these conditions as well.

The study adds to a growing body of bad news about how human activity is changing the planet’s climate and how dire those changes will be.

In the past, it has been common to combine together the results of dozens of these models, and so give a range for how much the planet might warm for a given level of carbon dioxide emitted into the atmosphere. That’s the practice of the leading international climate science body, the United Nations’ Intergovernmental Panel on Climate Change.

Instead, the new study compared these models’ performance with recent satellite observations of the actual atmosphere and, in particular, of the balance of incoming and outgoing radiation that ultimately determines the Earth’s temperature. Then, they tried to determine which models performed better. The research found the models that do the best job capturing the Earth’s actual “energy imbalance,” as the authors put it, are also the ones that simulate more warming in the planet’s future.

Source: https://www.washingtonpost.com/news/energy-environment/wp/2017/12/06/the...