A new study in Nature [Ed-Abstract only for non-subscribers, but see below.] predicts that climate warming will be 15% greater than previous high estimates have predicted. This new study suggests that humans need to reduce greenhouse gas emissions more than previously expected and more than the Paris Agreement calls for. This study was based on analyzing the earth's "energy budget" (absorption and re-emission of radiation) and inputting that into a number of different climate models.
Also covered in more detail in Phys.org and in the Guardian.
The researchers focused on comparing model projections and observations of the spatial and seasonal patterns of how energy flows from Earth to space. Interestingly, the models that best simulate the recent past of these energy exchanges between the planet and its surroundings tend to project greater-than-average warming in the future.
"Our results suggest that it doesn't make sense to dismiss the most-severe global warming projections based on the fact that climate models are imperfect in their simulation of the current climate," Brown said. "On the contrary, if anything, we are showing that model shortcomings can be used to dismiss the least-severe projections."
(Score: 2) by FatPhil on Friday December 08 2017, @08:21AM (3 children)
Their models were almost certainly *informed* by the recent past, in which case, the ability to identify one of their training images is hardly a surprise. Just flick the switch to "petril"...
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 5, Informative) by tonyPick on Friday December 08 2017, @09:07AM (2 children)
Maybe not. The paper itself is paywalled, but from
http://www.sciencemediacentre.org/expert-reaction-to-research-suggesting-greater-future-global-warming/ [sciencemediacentre.org]
The latest there is CMIP5: https://cmip.llnl.gov/cmip5/index.html [llnl.gov] (and this is referenced in the citations).
So they appear to be comparing data models trained on data which ends in the 2011-2013 range, with more recent observations.
Much more detail here...
https://patricktbrown.org/2017/11/29/greater-future-global-warming-inferred-from-earths-recent-energy-budget/ [patricktbrown.org]
Statistical methods here:
https://www.youtube.com/watch?v=5nGrLb5BARQ [youtube.com]
To quote "the end result is an observationally informed prediction with a spread about that prediction informed use a hold-one-out cross validation"
(Score: 2) by FatPhil on Friday December 08 2017, @12:28PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Friday December 08 2017, @01:52PM
If you compare to recent temperatures instead of radiation flux, it would seem that Brown and Caldeira's favored models are not the best ones.
https://patricktbrown.files.wordpress.com/2017/11/brown-caldeira-2017-nature.png [wordpress.com]