Thanks for sharing!

Here is an example from a proff I had. he was teaching field camp on the eastern sierras back in the mid 80′s. The camp was in a small valley below a rather large snow pack. A small stream ran through the valley, it was summer and quite hot. The proff wondered everyday how long the snow pack would last or how long it would take for it too melt. Weeks went by and the snow pack was still the same size. Then, in front of his and a few students eyes, all of the sudden the snow pack started to melt, and withing a few minutes a large flash flood of water was rushing down the valley towards the camp. The proff barely had enough time to warn the remaining students of the coming flash flood. Nobody was injured but the field camp tents, SUV’s and all were washed downvalley for some distance and much stuff was lost. We discussed this trying to figure out why it happened that way. Any thoughts?

yes, ther are, derived form in epth studies of a samle of glaciers.

The NAS report mentions them and their use.

and some advancing from the mid-late century cooling (middle part of the lag)

Why would they necessarily advance just because the temperature cooled? They’d still (arguably) be recovering from the LIA, just in cooler temps than the 1st half of the century. Take an ice cube out of the freezer and put it on the counter, and it will start melting. Put it in the fridge where the air is cooler than on the counter, and it will still continue to melt, just slower than it would on the counter. But for it to re-freeze, you’ve got to put it back in the freezer. If mid-19th century temps were warm enough to start widespread significant retreating, mid-late 20th century temps probably wouldn’t be cool enough for them to advance.

That’s why I mentioned looking at the rate of retreat and correlating it with local temps (while adjusting for lags, precipitation, of course, and any other factors that may exist – prevailing strong winds, for example?).

Are there sophisticated models – either general or for specific glaciers – which relate temperature and precipitation to the rate of advance and/or decline?

The fact is that in a multicausal system like the climate, you can NOT simply assert gradualism to say that the causes that were primary a century ago are still the causes that are primary now – even if the same overall set of potential causes are still the operative potential causes.

Yo posted aobut 10-70 year tim lags. If the past temperatures of the entire last century were what was the operative cause, and thsoe time algs were simple lnear lags, we would expect (to a first approximation) to see some still retreating from the early century warming (70 year end of the lag) and some advancing from the mid-late century cooling (middle part of the lag), and some starting to retreat now from late warming (short part of the lag).

Or if that is simply a measure of the uncertainty of a single estimate of the lag, and this is due to early century warming, then we ahve restricted the estimate to a short part of the long end of the uncertainty. The observations of currently elevating equilibrium lines in the glaciers, though, would argue strongly for mechanisisms operating today causing the shortening.

It is the processes that are the same. Sometimes they can be catostrophic (Lake Moussalla in Montana for instance), but generally they are a slow, gradual process. Hence soil science for example. Don’t tell me soils form rapidly or from catastophes please!

It is funny since the princepal is also fundemental to the study of biology. It took a geologist to show the biologists what was really going on. Here again we have the same thing happening.

No, Michael, I am not saying that.

You “strongly disagree” with me saying “we’d still be seeing glacial retreat today without anthro-GHG emissions,” but you aren’t saying “we wouldn’t be seeing glacial retreat today without anthro-GHG emissions?” So your answer is the Al Gore-esque “the scientists don’t know…they just don’t know.”

If you don’t want to venture into the world of making educated judgements, then just say so. But spare the childish sighs.