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If you are ever in the Engadin valley, I can recommend the Morteratsch Glacier trail. There are signs along the trail to indicate the historic positions of the

If you are ever in the Engadin valley, I can recommend the Morteratsch Glacier trail. There are signs along the trail to indicate the historic positions of the glacier. It's incredibly impressive how much the glacier retreated over the last few decades. It also really drives the point home that climate change isn't a new phenomenon, we've been at it for a couple centuries now. But it picked up a lot of speed recently.

cm2187 8y ago
I read that the retreat of some glaciers in the Alps uncovered ancient Roman artefacts like coins. So it is probably not the first time they retreat either.
- ggm 8y ago
  Do you believe inside the next 2000 years they will recover? The underlying premise is not that climate has not changed before. The premise is that there is no strong belief the cyclic nature of glacial retreat will be seen in any sensible timeframe (tens of thousands of years)
  - alexis_fr 8y ago
    There are hypotheses that the last mini ice age was caused by slaughtering native am populations in the 1500s, causing their crops to grow back. I’m not going to suggest a slaughter obviously, but an extremely strong economic recession could bring us back to pre-1990 carbon levels (when they were balanced, as per IPCC).
    - graeme 8y ago
      You're mixing up stocks and flows. Emissions are a flow. Co2 level is a stock. A recession will reduce the flow, but the stock will still increase. The hypothesized decrease of co2 in the 1500s from native american death was a decrease in the stock. Farmlands returned to wild states and sequestered carbon.
    - jellicle 8y ago
      The IPCC certainly has never said that "pre-1990" carbon emissions were balanced. https://www.esrl.noaa.gov/gmd/ccgg/trends/full.html https://www.esrl.noaa.gov/gmd/ccgg/trends/full.html
- tobltobs 8y ago
  How do you know that those coins haven't been dropped by someone crossing the glacier?
- arethuza 8y ago
  There was apparently a possible warm period during the later Roman period: https://en.wikipedia.org/wiki/Roman_Warm_Period https://en.wikipedia.org/wiki/Roman_Warm_Period
- kbutler 8y ago
  "The radiocarbon ages of tree fragments and peat discs found on proglacial forefields indicate 12 phases of glacier recessions during the Holocene. Locations and type of occurrence of the dated samples show that trees and mires grew where glaciers exist at present and, therefore, glaciers were smaller at that time. ... their pattern changed from long recessions (/500 yr) interrupted by short advances (B/200 yr) during the early Holocene to the opposite pattern with relatively short recessions and prolonged advances during the late Holocene (after 3.3 cal. kyr BP). It is important to recognize that this natural variability of glacier extent, which occurs on a centennial timescale, is superimposed on a much longer term, multimillennial-scale trend towards increased glacier extent culminating in the ‘Little Ice Age’." http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.483.4597&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.483... Glaciers in the alps have been advancing and receding for the last 10,000 years, with the last few thousand years primarily advancing through the little ice age. They are now retreating.

cm2187 8y ago

I read that the retreat of some glaciers in the Alps uncovered ancient Roman artefacts like coins. So it is probably not the first time they retreat either.

ggm 8y ago
Do you believe inside the next 2000 years they will recover? The underlying premise is not that climate has not changed before. The premise is that there is no strong belief the cyclic nature of glacial retreat will be seen in any sensible timeframe (tens of thousands of years)
- alexis_fr 8y ago
  There are hypotheses that the last mini ice age was caused by slaughtering native am populations in the 1500s, causing their crops to grow back. I’m not going to suggest a slaughter obviously, but an extremely strong economic recession could bring us back to pre-1990 carbon levels (when they were balanced, as per IPCC).
  - graeme 8y ago
    You're mixing up stocks and flows. Emissions are a flow. Co2 level is a stock. A recession will reduce the flow, but the stock will still increase. The hypothesized decrease of co2 in the 1500s from native american death was a decrease in the stock. Farmlands returned to wild states and sequestered carbon.
  - jellicle 8y ago
    The IPCC certainly has never said that "pre-1990" carbon emissions were balanced. https://www.esrl.noaa.gov/gmd/ccgg/trends/full.html https://www.esrl.noaa.gov/gmd/ccgg/trends/full.html
tobltobs 8y ago
How do you know that those coins haven't been dropped by someone crossing the glacier?
arethuza 8y ago
There was apparently a possible warm period during the later Roman period: https://en.wikipedia.org/wiki/Roman_Warm_Period https://en.wikipedia.org/wiki/Roman_Warm_Period
kbutler 8y ago
"The radiocarbon ages of tree fragments and peat discs found on proglacial forefields indicate 12 phases of glacier recessions during the Holocene. Locations and type of occurrence of the dated samples show that trees and mires grew where glaciers exist at present and, therefore, glaciers were smaller at that time. ... their pattern changed from long recessions (/500 yr) interrupted by short advances (B/200 yr) during the early Holocene to the opposite pattern with relatively short recessions and prolonged advances during the late Holocene (after 3.3 cal. kyr BP). It is important to recognize that this natural variability of glacier extent, which occurs on a centennial timescale, is superimposed on a much longer term, multimillennial-scale trend towards increased glacier extent culminating in the ‘Little Ice Age’." http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.483.4597&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.483... Glaciers in the alps have been advancing and receding for the last 10,000 years, with the last few thousand years primarily advancing through the little ice age. They are now retreating.