CO2 desorption was negligible for T > 1400 K, and CO desorption was observed to peak near ~1300 K, decreasing with temperature to ~1700 K, becoming nearly constant at higher temperatures. The dominant product over the 1200 to 2300 K range was, however, O atoms produced by thermal desorption from -C(O), with negligible production of O2 under their conditions. Our conditions are different (continuous low PO2 vs. pulsed O atom exposures), but it is reasonable to assume that oxygen desorption is also an important channel for -C(O) decay in our experiments, competing with CO desorption and suppressing the etching rates.