HadCM3 turns 18 (ish) and vegetation over 120 ka

HadAM3 was first introduced to the world in about 1999, and in 2017 it’s still going strong.¬†When a model is pretty much old enough to smoke, drink, drive and has multiple offspring – what do you do to celebrate? Well, we gave HadCM3 a model and configuration description paper. (There may also have been cake.) The GMD paper has been over a year in the making, a big group effort by all of the users of HadCM3 in BRIDGE, and as the primary co-ordinator of the paper, I’m really glad . The paper is in review with GMD, so you can take a early peek at it.

As a smaller celebration, HadCM3 is the model used in a paper showing an ensemble of 124 (yep really, not a typo) simulations that make up time snapshots of the last 120 ka, with and without vegetation. What we show is that whereas in the near future the carbon is often the dominant terrestrial biosphere effect on climate, the longer timespans and greater uncertainty of the carbon under icesheets and on now submerged land mean that the biogeophysical (albedo, etc.) effects are very dominant. This paper is also in open review, with Climate of the Past. So if you feel the need to sneak an early look at how vegetation affects climate over the last glacial-interglacial cycle, you can do so.