Want your surgeon to use antibiotics and wash his or her hands? Why? I'm sure you'll be fine. After all, Germ Theory is "just a theory".
Anyway, the letter is still solid, and I thoroughly endorse its sentiments, particularly this:
"there is nothing remotely identified in the recent events that changes the fundamental conclusions about climate change:
(i) The planet is warming due to increased concentrations of heat-trapping gases in our atmosphere. A snowy winter in Washington does not alter this fact."