Our paper on Last Glacial Maximum (LGM) cooling and climate sensitivity is out today in @nature! This represents four years of work, so it feels really good to see it released. Here's a short thread on what it means... nature.com/articles/s4158…
First we compile almost 2,000 geological measurements of sea-surface temperature, which believe me took some time! Then, we ran new simulations of the LGM with the @NCAR_Science CESM model, and used data assimilation to combine the info. This gives us global maps of temperature! 
This new analysis suggests that globally, the LGM was 6C (11F) colder than preindustrial times. This is a little colder some previous estimates but agrees well w/ others
Combining our new estimate with ice core CO2 values, we can calculate climate sensitivity. Take away - our median value is 3.4C, and there is very little chance it is below 2.4C. Since the LGM is a cold climate, we consider this a "lower bound" on what ECS can be.
Results of the study available on Pangaea.de but also on Github so you can download and plot the results! Big thanks to my collaborators @sbmalev, @cjpoulsen, @Climate_Z, my student Jonathan King for designing a new code base, and Greg Hakim! github.com/jesstierney/lg…
And here's the readcube link for free viewing! rdcu.be/b6tx9
