A new study by a team of scientists from the US and the UK explains how differing climate model projections can be used collectively to reduce uncertainties in future climate change.
Despite major advances in climate modelling over the last 30 years, there are still a wide range of projections for global warming by 2100, even when the same scenarios of carbon dioxide emissions are assumed in each model. This is because there are continuing uncertainties in climate feedbacks, such as the snow-albedo feedback. This is how much declining snow-cover under global warming will amplify the global warming by making the Earth’s surface darker so that it absorbs more sunlight.
The range of climate projections is primarily used to assess the uncertainties and possible risks associated with greenhouse gas emissions, but the authors of this new study describe a more constructive way to use the model spread, called Emergent Constraints. The basic idea is to use the models to tell us which aspects of the current climate are most related to differences in the future climate. Then a measurement of those aspects in the real world can be used to select out the most likely future climates.
The study is published in the journal Nature Climate Changeon Monday, March 18 2019.
Read more at University of Exeter
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