Scientists are starting to clear up one of the biggest controversies in climate science – Washington Post
How much Earth will warm in response to future greenhouse gas emissions may be one of the most fundamental questions in climate science — but it’s also one of the most difficult to answer. And it’s growing more controversial: In recent years, some scientists have suggested that our climate models may actually be predicting too much future warming, and that climate change will be less severe than the projections suggest.
But new research is helping lay these suspicions to rest. A study, out Wednesday in the journal Science Advances, joins a growing body of literature that suggests the models are on track after all. And while that may be worrisome for the planet, it’s good news for the scientists working to understand its future.
The new study addresses a basic conflict between what the models suggest about future climate change and what we can infer from historical observations alone. Some scientists have suggested that the models may be too sensitive, pointing out that the warming they predict for the future is greater than what we would expect based only on the warming patterns we’ve observed since humans began emitting greenhouse gases.
The models, for instance, suggest that if the carbon dioxide concentration in the atmosphere were to reach double its preindustrial level, the planet would warm by anywhere from about 1.5 to 4.5 degrees Celsius (2.7 to 8.1 Fahrenheit). But the warming patterns we’ve actually observed over the past 200 years or so would suggest that a doubling in carbon dioxide should only lead to about 3 degrees Celsius (5.4 Fahrenheit) of warming at the most.