Occasional Thoughts on Climate Change

[donsutherland1]

1 hour ago, GaWx said:

 Thanks. But this graph has avg for entire summer well over 0C? This is far warmer than what Chris Martz was suggesting about the site of the collapse (i.e., only occasionally reaching to barely above freezing), isn’t it?

Here's where I think the issue lies. The graph is based on where the collapsing rock/glacier hit the valley (around 4,300 meters above sea level). The bedrock, glacier was about 5,200 meters. So, the graph is correct in that the region has been warming, but it is not the mean temperature of the actual glacier. Nevertheless, preceding the collapse, temperatures had reached 90° or above in Kathmandu. At standard lapse rates, that would suggest readings in the middle 40s at the altitude of the glacier. During the June 1-August 25 period, Kathmandu had 77 days with highs of 80° or above. At standard lapse rates, that would amount to highs of 35° or above at 5,200 meters. So, at least using the standard lapse rates and Kathmandu's data, most of the summer days saw at least some melting where the collapse took place.

[chubbs]

5 hours ago, donsutherland1 said:

Here's where I think the issue lies. The graph is based on where the collapsing rock/glacier hit the valley (around 4,300 meters above sea level). The bedrock, glacier was about 5,200 meters. So, the graph is correct in that the region has been warming, but it is not the mean temperature of the actual glacier. Nevertheless, preceding the collapse, temperatures had reached 90° or above in Kathmandu. At standard lapse rates, that would suggest readings in the middle 40s at the altitude of the glacier. During the June 1-August 25 period, Kathmandu had 77 days with highs of 80° or above. At standard lapse rates, that would amount to highs of 35° or above at 5,200 meters. So, at least using the standard lapse rates and Kathmandu's data, most of the summer days saw at least some melting where the collapse took place.

The graph says the temperatures were estimated with ERA re-analysis bias corrected to 5200 feet using regional high elevation weather stations.  

[donsutherland1]

6 minutes ago, chubbs said:

The graph says the temperatures were estimated with ERA re-analysis bias corrected to 5200 feet using regional high elevation weather stations.  

I may be referring to a different article. I was citing a ClimateBrink piece by Zeke Hausfather, which didn't mention bias correction.

https://www.theclimatebrink.com/p/what-we-can-and-cannot-say-about

 

[chubbs]

10 hours ago, donsutherland1 said:

I may be referring to a different article. I was citing a ClimateBrink piece by Zeke Hausfather, which didn't mention bias correction.

https://www.theclimatebrink.com/p/what-we-can-and-cannot-say-about

 

That chart is roughly 5C higher than the one I posted, 8C vs 3C for 2026 for instance. The 5C difference makes sense given the 900m difference in the elevation basis of the estimates. 

[donsutherland1]

43 minutes ago, chubbs said:

That chart is roughly 5C higher than the one I posted, 8C vs 3C for 2026 for instance. The 5C difference makes sense given the 900m elevation difference in the elevation basis of the estimates. 

Thank you. Yes, that makes sense and it’s clear that there are many days where the mercury exceeds freezing.

[Chinook]

Warmest, or 2nd or 3rd warmest August for north Texas to Wyoming, to Los Angeles

 

[chubbs]

 

A post-collapse picture of the Nepal avalanche site shows multiple meltwater streams from the glacier remains. Including those clearly sourced from cooler elevations above the collapsed zone. Further supporting the above freezing temperature estimates for the site. 

 

[chubbs]

Here' the past 30 days temperature data for the Everest Base Camp. All days are above freezing, reaching as warm as 10C. Temperatures below freezing have been rare in the past month. Even Camp 2 at 6464m has been above freezing most days. It took me a few seconds to google up this data.  

https://scidata.appstate.edu/everest/

 

 

[bluewave]

 

Climatologist49 @climatologist49.bsky.social

· 1d

Nepal observed their warmest August nationwide, with the most anomalous region being the border with China/Tibet. It is hard to imagine that record warm temps did not hasten the bedrock/glacier collapse disaster.

[Typhoon Tip]

10 hours ago, bluewave said:

 

Climatologist49 @climatologist49.bsky.social

· 1d

Nepal observed their warmest August nationwide, with the most anomalous region being the border with China/Tibet. It is hard to imagine that record warm temps did not hasten the bedrock/glacier collapse disaster.

Of course it did

there was never any debate by anyone not either deluded or immoral - pick

[WolfStock1]

On 9/7/2026 at 7:20 AM, bluewave said:

 

Climatologist49 @climatologist49.bsky.social

· 1d

Nepal observed their warmest August nationwide, with the most anomalous region being the border with China/Tibet. It is hard to imagine that record warm temps did not hasten the bedrock/glacier collapse disaster.

 

Yes very true - it appears very evident that it did.

Question is - was it a case of "hastening" (as in - it would have collapsed at some point, warming just made it collapse sooner than otherwise), or was it a case of "causing" (as in - if this level of warming hadn't happened - it would not have ever collapsed)?

Probably will never know of course.

Plenty of glacier collapses of course happened in pre-warming times, e.g. several big ones in the early 1800's in Switzerland, France, and Caucasus mountains.

 

[FPizz]

14 minutes ago, WolfStock1 said:

 

Yes very true - it appears very evident that it did.

Question is - was it a case of "hastening" (as in - it would have collapsed at some point, warming just made it collapse sooner than otherwise), or was it a case of "causing" (as in - if this level of warming hadn't happened - it would not have ever collapsed)?

Probably will never know of course.

Plenty of glacier collapses of course happened in pre-warming times, e.g. several big ones in the early 1800's in Switzerland, France, and Caucasus mountains.

 

 It is hard to imagine that record warm temps did not hasten the bedrock/glacier collapse disaster. 

That part is just pure conjecture really.  Maybe years of earthquakes over somewhat young fragile mountains causing lots of micro-fractures in the bedrock in that region was the main driver.  Very large uptick in 2025 could have easily caused lots of fractures and crumbling, and this is only 4.0 or greater.  

[TheClimateChanger]

Not to change the subject, but one thing I find interesting is recent CONUS temperatures - while historically record-breaking - are not really far removed from the expected baseline. With the controversy over RCP8.5 / SSP5-8.5 in the NCA5 report, I took a look at it. Figure 1.15 was interesting... note that the caption in the text of the document states that the US average temperature is all 50 states, plus Puerto Rico. However, this appears to be erroneous. The reported 1991-2020 ("current") average is identical to the NCEI CONUS mean (53.3F). Obviously, including Alaska would lower that as it 17% of the total area of the CONUS with a mean more than 25F lower. Hawaii and PR are both warmer (not by as much as you might think due to terrain) but are negligible area. So I'm pretty confident that is actually the CONUS mean and the caption is incorrect.

Anyways, at 1.5C, we see the mean jumps to 55.3F. In 2024, with global temps around that 1.5C level, we had a mean of 55.4F - hottest on record. This year is certain to exceed that and possibly become the first year over 56F. So this year might be legitimately a bit above the new baseline for national temps, but not by much. I could see where next year - with the strong El Nino - could be 56.5F+. A cold year under today's baseline would likely be no colder than the existing climatological normal. It's pretty fascinating to consider, when you think of all of the crazy records we've seen this year (e.g., the March heat, record summer, etc...). This is really just the new norm, and not that spectacular at all. With 2 of the last 3 years (2026 almost certain) to be around/above the modeled value for a 1.5C world - and 2027 very likely to do so as well, with the added El Nino warming - the modeled projection looks quite accurate to me, as we now have some real-world data to compare to.

At 2C global warming, which is very likely by mid-century, the CONUS mean reaches 56.6F. Warm years could be from 57.5-58F+ or 2-2.5F+ warmer than the present record, with even a cold year being not much colder than 2024.

At 3C global warming, models suggest the CONUS mean temperature would reach 59.1F. At that level of warming, every year would be far warmer than 2024 - even a cold year, probably even a volcanically enhanced cold year. Such a degree of warming is possible, but far from guaranteed, by the latter portion of this century.

At 4C global warming, models suggest the CONUS mean temperature would reach about 60.8F. Such a degree of warming is very unlikely this century with the retirement of RCP8.5 / SSP5-8.5 but remains possible in the 22nd century.