What Counts as Geologically Rapid Warming?
I frequently hear people downplay the claim that the 1.3°C warming above the 1850-1900 mean is geologically significant. I hear words like "slight" or "modest" or "insignificant" thrown around a lot. And certainly global temperatures have increased by a lot more than 1.3°C on geologic time scales. My first response is typically to point out that on geologic time scales, global temperatures do change a lot, but at much slower rates. Current warming rates are exceptional, even on geologic time scales. And I think this point can be relatively easily demonstrated with the evidence we have, even taking into consideration the fact that proxies do not preserve a high degree of temporal resolution, and actual warming rates may exceed what we can detect with proxy evidence. I think we need a two part response to this. Defining Geologically "Rapid" Warming Since terms like "rapid" are relative terms, I think we need to come up with a standard for...