Wednesday, April 01, 2015

A GISS Model vs GISS Observed Warming


Stefanthedenier said...

David, I would like to ask you for advice: because forests and deserts have same amount of CO2; do they have same climate?!If CO2 was regulating the climate, it should be OR: the ''climate scientist'' don't know what the ''real climate'' is?! why are you people confusing the phony global warming, with the normal / regular climatic changes?! happy Easter david!

Stefanthedenier said...

David, please you ''Peer review'' my post. use your most critical eye BUT please be honest and objective:

Steve said...

Thanks for this David. The "Skeptics" compare observations with ensemble means, which is the easiest way they can make their point. A better method would be to see which individual models best represent the observations, as you have done here.

A complaint could be made that you have chosen the RCP that has the least CO2 emissions, but looking at the RCPs it seems to me that the levels of CO2 concentrations over the period you have chosen are similar.

It would be interesting, though, to see the GISS model results with the other RCPs.

David Appell said...

Thanks Steve. I have also looked at RCP 6.0 for this model. The RCPs don't diverge until 2005; before that they all use the same GHG concentrations.

With RCP 6.0, the additional warming by 2015, above RCP 2.6, is only +0.01 C.

I agree that computing multi-model averages can be misleading, simply because all models aren't created equal.

I picked a GISS model, because I've been reading a paper about it, and because I wanted to learn about how to use CMIP5 data. The paper: