by W. Eschenbach, Apr 2020 in WUWT
Gavin Schmidt is a computer programmer with the Goddard Institute of Space Sciences (GISS) and a noted climate alarmist. He has a Ph.D. in applied mathematics. He’s put together a twitter threadcontaining what he sees as some important points of the “testable, falsifiable science that supports a human cause of recent trends in global mean temperature”. He says that the slight ongoing rise in temperature is due to the increase in carbon dioxide (CO2) and other so-called “greenhouse gases”. For simplicity, I’ll call this the “CO2 Roolz Temperature” theory of climate. We’ve discussed Dr. Schmidt’s ideas before here on WUWT.
Now, Gavin and I have a bit of history. We first started corresponding by way of a climate mailing list moderated by Timo Hameraanta back around the turn of the century, before Facebook and Twitter.
The interesting part of our interaction was what convinced me that he was a lousy programmer. I asked him about his program, the GISS Global Climate Model. I was interested in how his model made sure that energy was conserved. I asked what happened at the end of each model timestep to verify that energy was neither created nor destroyed.
He said what I knew from my own experience in writing iterative models, that there is always some slight imbalance in energy from the beginning to the end of the timestep. If nothing else, the discrete digital nature of each calculation assures that there with be slight roundoff errors. If these are left uncorrected they can easily accumulate and bring the model down.
He said the way that the GISS model handled that imbalance was to take the excess or the shortage of energy and sprinkle it evenly over the entire planet.
Now, that seemed reasonable for trivial amounts of imbalance coming from digitization. But what if it were larger, and it arose from some problem with their calculations? What then?
So I asked him how large that energy imbalance typically was … and to my astonishment, he said he didn’t know.
Amazed, I asked if he had some computer version of a “Murphy Gauge” on the excess energy. A “Murphy Gauge” (below) is a gauge that allows for Murphy’s Law by letting you set an alarm if the variable goes outside of the expected range … which of course it will, Murphy says so. On the computer, the equivalent would be something in his model that would warn him if the excess or shortage of energy exceeded some set amount.