4 ms·

There have been some previous discussions on HN about this weather event in the Pacific Northwest, for example https://news.ycombinator.com/item?id=27670739 htt

There have been some previous discussions on HN about this weather event in the Pacific Northwest, for example https://news.ycombinator.com/item?id=27670739 https://news.ycombinator.com/item?id=27670739 One thing I want to mention is that it is not known if this heat wave is caused by climate change or not. A UW professor named Cliff Mass, who specializes in climate science and has written books about the weather of the Pacific Northwest, has specifically said (https://cliffmass.blogspot.com/2021/06/incredible-temperatures-are-being.html https://cliffmass.blogspot.com/2021/06/incredible-temperatur...): > Is global warming contributing to this heatwave? The answer is certainly yes. Would we have had a record heatwave without global warming. The answer is yes as well. He also said in the same article: > Let me end with the golden rule of temperature extremes: the bigger the temperature extreme the SMALLER the contribution of global warming. Think about that.

angst_ridden 5y ago
The thing is, this is a chaotic effect of the jet stream going into tighter oscillations. Think of a river in a flat area meandering more and more until oxbows form. It's an analogous phenomenon with the jet stream and pressure. The jet stream tends to follow warmer air, which means increased temperatures overall give a "flatter" plain to meander on, to return to the analogy. Obviously, like anything, it's far more complex than the analogy permits.
throwawayuw 5y ago
Throwaway as well because I've worked with Cliff Mass and am not interested in being at the receiving end of the retaliation that he's known for doling out. Cliff is kind of a pariah among meteorologists and climate scientists. He _loves_ that fact, and revels in this idea that he's the lone genius who got it right while the rest of the community got it wrong on climate change. But he's not viewed as someone who makes credible statements, particularly as they pertain to questions about climate. Many of his blog posts are deliberately misleading or contain incorrect information. Others I'd categorize as "You're not wrong... you're just an asshole." He has a decent understanding of some of the meteorological phenomena that are unique to the Puget Sound region, but even there I take every word he writes with a grain of salt. Sure, read his blog to understand how the snow is going to be this weekend at Crystal. But I'd leave it at that.
- throwawaysea 5y ago
  > But he's not viewed as someone who makes credible statements, particularly as they pertain to questions about climate. Based on what evidence? Cliff Mass is a tenured professor of Atmospheric Science at UW, has written the definitive book on Northwest climate (https://www.amazon.com/Weather-Pacific-Northwest-Cliff-Mass/dp/0295748443/ https://www.amazon.com/Weather-Pacific-Northwest-Cliff-Mass/...), leads the University of Washington Mesoscale Analysis and Forecasting Group, is the chief scientist of the Northwest Modeling Consortium, and is a fellow of the American Meteorological Society. Your comment seeks to discredit him in the very space he is broadly recognized for as an expert. I can't accept a vague attack on him that provides no supporting evidence. It comes off a lot like the attacks made by extremist climate activists when Cliff Mass corrects their understanding and brings them back to a balanced reality of what is going on.
- lovemenot 5y ago
  Would you mind explaining your reasoning. This statement about climate for instance: "the bigger the temperature extreme the SMALLER the contribution of global warming... " Is it wrong? If so, how so?
  - throwawayuw 5y ago
    Yes, it's backwards. The most common way this is quantified is using Fraction of Attributable Risk (FAR) [0]. Even if the mean of the temperature distribution is just shifted slightly upward with no change in shape, the higher the threshold, the larger the fraction of risk that is attributable to the change in mean. This holds for all but pathological distributions, and doesn't even require increased variability or anything like that. [0] Figure 1.1f here: https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/05_SROCC_Ch01_FINAL.pdf https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/05_S...
    - lovemenot 5y ago
      Thank you. This makes sense now and seems to me the right way of looking at the matter. I think I now understand what Mass was doing. Something like: "The bigger my overall remuneration (salary + bonus) the smaller the relative contribution made by my fixed salary." Right answer, wrong question.

angst_ridden 5y ago

The thing is, this is a chaotic effect of the jet stream going into tighter oscillations. Think of a river in a flat area meandering more and more until oxbows form. It's an analogous phenomenon with the jet stream and pressure. The jet stream tends to follow warmer air, which means increased temperatures overall give a "flatter" plain to meander on, to return to the analogy. Obviously, like anything, it's far more complex than the analogy permits.

throwawayuw 5y ago

Throwaway as well because I've worked with Cliff Mass and am not interested in being at the receiving end of the retaliation that he's known for doling out. Cliff is kind of a pariah among meteorologists and climate scientists. He _loves_ that fact, and revels in this idea that he's the lone genius who got it right while the rest of the community got it wrong on climate change. But he's not viewed as someone who makes credible statements, particularly as they pertain to questions about climate. Many of his blog posts are deliberately misleading or contain incorrect information. Others I'd categorize as "You're not wrong... you're just an asshole." He has a decent understanding of some of the meteorological phenomena that are unique to the Puget Sound region, but even there I take every word he writes with a grain of salt. Sure, read his blog to understand how the snow is going to be this weekend at Crystal. But I'd leave it at that.

throwawaysea 5y ago
> But he's not viewed as someone who makes credible statements, particularly as they pertain to questions about climate. Based on what evidence? Cliff Mass is a tenured professor of Atmospheric Science at UW, has written the definitive book on Northwest climate (https://www.amazon.com/Weather-Pacific-Northwest-Cliff-Mass/dp/0295748443/ https://www.amazon.com/Weather-Pacific-Northwest-Cliff-Mass/...), leads the University of Washington Mesoscale Analysis and Forecasting Group, is the chief scientist of the Northwest Modeling Consortium, and is a fellow of the American Meteorological Society. Your comment seeks to discredit him in the very space he is broadly recognized for as an expert. I can't accept a vague attack on him that provides no supporting evidence. It comes off a lot like the attacks made by extremist climate activists when Cliff Mass corrects their understanding and brings them back to a balanced reality of what is going on.
lovemenot 5y ago
Would you mind explaining your reasoning. This statement about climate for instance: "the bigger the temperature extreme the SMALLER the contribution of global warming... " Is it wrong? If so, how so?
- throwawayuw 5y ago
  Yes, it's backwards. The most common way this is quantified is using Fraction of Attributable Risk (FAR) [0]. Even if the mean of the temperature distribution is just shifted slightly upward with no change in shape, the higher the threshold, the larger the fraction of risk that is attributable to the change in mean. This holds for all but pathological distributions, and doesn't even require increased variability or anything like that. [0] Figure 1.1f here: https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/05_SROCC_Ch01_FINAL.pdf https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/05_S...
  - lovemenot 5y ago
    Thank you. This makes sense now and seems to me the right way of looking at the matter. I think I now understand what Mass was doing. Something like: "The bigger my overall remuneration (salary + bonus) the smaller the relative contribution made by my fixed salary." Right answer, wrong question.