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I was up at Camp Muir on Mt. Rainier for the first time in 29 years last weekend. It's located at 10,000 feet and is surrounded by glaciers. The temperature was

I was up at Camp Muir on Mt. Rainier for the first time in 29 years last weekend. It's located at 10,000 feet and is surrounded by glaciers. The temperature was around 60F in the sun. We're getting temps in May/June that were rarely seen in August in previous decades. The impressive thing is how quickly the glaciers are receding. The Nisqually glacier, which used to be down near 4000 feet in the 1970s is about a mile shorter. The ablation boundaries on many of the glaciers appear to be high up the mountain (like around 12,000 feet), which means they are going to shrink quite a bit more. I didn't expect this but there's a possibility that many of the Mt. Rainier glaciers will be gone in the next 30 years. This is a massive change to ecosystems from sea level up to the highest peaks.

pier25 7y ago
Considering climate lag (see below) it's almost certain most glaciers on Earth will be gone in 30 years. There is a delay of a couple of decades between emissions and effects on the climate. This means we are now seeing the effects from the emissions from the 70s and early 80s. The problem is that we have emitted more GHG in the last 40 years than the previous 150 years since the industrial revolution started. We have a huge climate bill to pay even if we magically stopped all emissions today.
- hodgesrm 7y ago
  The glaciers on Cascade mountains are relatively small but on Mt. Rainier it's extremely unlikely they will disappear in 30 years. The Emmons and Tahoma for example are large and start at 14,000 feet. They will continue to have accumulation zones for many decades. Plus it takes a while for ice to melt even with heat waves, even at lower elevations and even if the temperature rise accelerates. That said it's not unreasonable to suggest that glaciers with an accumulation zone below say 8-9,000 feet will be toast. That takes out most glaciers in the Cascades outside of the volcanoes and a few peaks in the North Cascades. I was just eyeballing things based on having spent a lot of time on the mountain, but this conclusion seems to be supported by recent geological work. [1, 2] [1] https://gsa.confex.com/gsa/2017AM/webprogram/Paper299694.html https://gsa.confex.com/gsa/2017AM/webprogram/Paper299694.htm... [2] https://glaciers.nichols.edu/north-cascade-glacier-retreat/ https://glaciers.nichols.edu/north-cascade-glacier-retreat/
snowwrestler 7y ago
I have a collection of climbing magazines from the 1990s, and many of the featured routes in South American ranges like the Cordilla Blanca are no longer climbable today. The glaciers, ice, and snow are gone, and what's left is crumbly, friable rock that is not safe to climb on. Mt Rainier is also mostly composed of crumbly, friable rock, and I wonder just how climbable it would be without glaciers and snowfields to provide secure footing and keep rocks from falling down on people.
- hodgesrm 7y ago
  Rockfall has always been part of the fun of climbing on the upper parts of Mt Rainier. The practical effect of warming is that the season where you need to worry about it is now extended. What's more worrying is the possibility we'll see some major collapses. Many of the big features on Rainier like Gibraltar Rock and the Willis Wall are anchored by ice at the base. As this disappears those structures may become unstable. It's conceivable that collapse could trigger lahars, which are a big risk for people in the valleys below the mountain. In the past these have run all the way out to Puget Sound.
  - snowwrestler 7y ago
    I doubt that the gravitational collapse of a rock buttress, even a large one, would be enough to trigger a major eruption of Rainier. The energy of an eruption is shockingly large and almost anything else you can imagine pales before it. The thickness and weight of the entire mountain is not a significant check on an eruption; therefore, it doesn't seem likely that removing a portion of the mountain (via collapse) would do more than vent some steam and noxious gases. Eruptions depend on what happens deeper in the crust, as I understand it.
    - hodgesrm 7y ago
      Lahars are different. They are mudflows. It's common to see them triggered by eruptions (e.g., Mt St Helens in 1980) but they can arise from landslides as well as glacier collapses. The most recent Lahar on Mt Rainier was in 1947. [1] [1] https://en.wikipedia.org/wiki/Kautz_Creek https://en.wikipedia.org/wiki/Kautz_Creek

pier25 7y ago

Considering climate lag (see below) it's almost certain most glaciers on Earth will be gone in 30 years. There is a delay of a couple of decades between emissions and effects on the climate. This means we are now seeing the effects from the emissions from the 70s and early 80s. The problem is that we have emitted more GHG in the last 40 years than the previous 150 years since the industrial revolution started. We have a huge climate bill to pay even if we magically stopped all emissions today.

hodgesrm 7y ago
The glaciers on Cascade mountains are relatively small but on Mt. Rainier it's extremely unlikely they will disappear in 30 years. The Emmons and Tahoma for example are large and start at 14,000 feet. They will continue to have accumulation zones for many decades. Plus it takes a while for ice to melt even with heat waves, even at lower elevations and even if the temperature rise accelerates. That said it's not unreasonable to suggest that glaciers with an accumulation zone below say 8-9,000 feet will be toast. That takes out most glaciers in the Cascades outside of the volcanoes and a few peaks in the North Cascades. I was just eyeballing things based on having spent a lot of time on the mountain, but this conclusion seems to be supported by recent geological work. [1, 2] [1] https://gsa.confex.com/gsa/2017AM/webprogram/Paper299694.html https://gsa.confex.com/gsa/2017AM/webprogram/Paper299694.htm... [2] https://glaciers.nichols.edu/north-cascade-glacier-retreat/ https://glaciers.nichols.edu/north-cascade-glacier-retreat/

snowwrestler 7y ago

I have a collection of climbing magazines from the 1990s, and many of the featured routes in South American ranges like the Cordilla Blanca are no longer climbable today. The glaciers, ice, and snow are gone, and what's left is crumbly, friable rock that is not safe to climb on. Mt Rainier is also mostly composed of crumbly, friable rock, and I wonder just how climbable it would be without glaciers and snowfields to provide secure footing and keep rocks from falling down on people.

hodgesrm 7y ago
Rockfall has always been part of the fun of climbing on the upper parts of Mt Rainier. The practical effect of warming is that the season where you need to worry about it is now extended. What's more worrying is the possibility we'll see some major collapses. Many of the big features on Rainier like Gibraltar Rock and the Willis Wall are anchored by ice at the base. As this disappears those structures may become unstable. It's conceivable that collapse could trigger lahars, which are a big risk for people in the valleys below the mountain. In the past these have run all the way out to Puget Sound.
- snowwrestler 7y ago
  I doubt that the gravitational collapse of a rock buttress, even a large one, would be enough to trigger a major eruption of Rainier. The energy of an eruption is shockingly large and almost anything else you can imagine pales before it. The thickness and weight of the entire mountain is not a significant check on an eruption; therefore, it doesn't seem likely that removing a portion of the mountain (via collapse) would do more than vent some steam and noxious gases. Eruptions depend on what happens deeper in the crust, as I understand it.
  - hodgesrm 7y ago
    Lahars are different. They are mudflows. It's common to see them triggered by eruptions (e.g., Mt St Helens in 1980) but they can arise from landslides as well as glacier collapses. The most recent Lahar on Mt Rainier was in 1947. [1] [1] https://en.wikipedia.org/wiki/Kautz_Creek https://en.wikipedia.org/wiki/Kautz_Creek