Hmm-- I hope I'm not posting out of place tonight. This issue of climate change is popping up on the hazards discussion site in preparation for tomorrow, but I see the last posts were two months ago. Still, we were asked to address three aspects, so here is my post #3 :>)
I like to use recent climate change (past 10,000 years) to show the nature of change through time. My emphasis on time goes beyond the usual deep time (age) and ordering of events offered in most geology texts. For nearly twenty years I've also emphasized additional qualities such as patterns, magnitudes, frequencies, durations, and rates.
With all the emphasis on human-caused climate change, I've found that many students believe that if anthropogenic cycling of carbon ceased, then we'd have no changes to contend with at all. The most dangerous parts of such delusional thinking are (a) that carrying capacity of the planet is fixed and static, (b) that we can safely build to that capacity and (c) natural climate changes take place over hundreds of thousands of years if not longer and are neither rapid nor noticeable in the short term.
In 2008, university presidents and chancellors circulated and signed a letter advocating sustainability "...to reestablish the more stable climatic conditions that have made human progress over the last 10,000 years possible." I'd rather that the important issue of sustainability were championed through less carelessly written documents.
For a long time I've used the varved record in the Elk Lake core to have students confront their assumptions about these qualities of time. It shows four distinct climate changes in the past 10,000 years, which if repeated would certainly cause hardship on a planet built out "to capacity." A student & I published a paper (Journal of Geoscience Education, v. 55, n. 1, January, 2007, p. 36-50) on the uses of many exercises to teach about qualities of change through time, and the Elk Lake exercise is outlined in there.
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