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]

1 hour 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 elevation difference in the elevation basis of the estimates.