After just viewing coal statistics the dismal wag in me is moved to read the title of Roberts’ excellent talk as “Climate change is simple: we’re screwed.”
Perhaps tomorrow morning I’ll feel more optimistic.
At fourteen minutes David Roberts makes the assertion that under the worse case scenario which he is discussing areas which have known 80◦ F temperatures could see temperatures of 170◦ to 180◦ F. This strikes me as being an outlandish prediction. I have read the article which Mr. Roberts cites in his ancillary material on his web page (McMichael and Dear, PNAS, May 25, 2010, vol. 107 no. 21) and could find no reference to maximum temperatures of this sort. McMichael and Dear are commenting on Sherwood and Huber’s article in the same issue of the Proceedings of the National Academy of Sciences, “An adaptability limit to climate change due to heat stress”. Here again no such numbers are to be found. If anyone can offer me good reason to give these numbers credence I would be eager to hear them.
There can be little doubt that there is a real limit to the temperatures which human beings can survive in. The key number Sherwood speaks of is wet-bulb temperatures in excess of 35◦ C. These temperatures are characterized as being practically intolerable. There is a difference between normal and wet-bulb temperatures. United States infantry are said to have been exposed to temperatures of 50◦ C (122◦ F) for extended periods of time while wearing body armor during the recent war in Iraq. This gives me reason to wonder at the validity of the temperatures cited. None of this changes the mute fact that there are very real limits to what human beings can tolerate.
It’s distracting when/if it’s noticed; I didn’t notice that number the first time through (glazing after hearing too much familiar info?) but after you pointed it out I listened back to what didn’t really sound like a miscue. A careful listener will be arrested by that number and then of course will wonder about everything else in the talk.
Might ask David himself; he’s got a comments thread on this at his blog.
I think I see where that high number came from: It’s a dry-bulb equivalent or perhaps a heat index figure. From the linked WP page:
“Outdoors in open conditions, as the relative humidity increases, first haze and ultimately a thicker cloud cover develops, reducing the amount of direct sunlight reaching the surface. Thus, there is an inverse relationship between maximum potential temperature and maximum potential relative humidity. Because of this factor, it was once believed that the highest heat index reading actually attainable anywhere on Earth is approximately 71 °C (160 °F). However, in Dhahran, Saudi Arabia on July 8, 2003, the dewpoint was 35 °C (95 °F) while the temperature was 42 °C (108 °F), resulting in a heat index of 78 °C (172 °F). This is comparable to the temperatures that are recommended to kill bacteria in many meat products and it is common in a sauna.” (Emphasis added.)
I suspect Dave may have been mixing a dry-bulb apple with a heat index orange in the figures he cited, but if so that’s an understandable conflation given that he wasn’t reading from a prepared text.
Somewhat off-topic, I suppose, but Paul Krugman’s latest TNYT op-ed is quite good. Clearly the powers-that-be are out of touch with reality. That includes the Chinese powers-that-be after reading China’s latest coal plan.
The first commenter above has the right of it, I fear.
After just viewing coal statistics the dismal wag in me is moved to read the title of Roberts’ excellent talk as “Climate change is simple: we’re screwed.”
Perhaps tomorrow morning I’ll feel more optimistic.
At fourteen minutes David Roberts makes the assertion that under the worse case scenario which he is discussing areas which have known 80◦ F temperatures could see temperatures of 170◦ to 180◦ F. This strikes me as being an outlandish prediction. I have read the article which Mr. Roberts cites in his ancillary material on his web page (McMichael and Dear, PNAS, May 25, 2010, vol. 107 no. 21) and could find no reference to maximum temperatures of this sort. McMichael and Dear are commenting on Sherwood and Huber’s article in the same issue of the Proceedings of the National Academy of Sciences, “An adaptability limit to climate change due to heat stress”. Here again no such numbers are to be found. If anyone can offer me good reason to give these numbers credence I would be eager to hear them.
There can be little doubt that there is a real limit to the temperatures which human beings can survive in. The key number Sherwood speaks of is wet-bulb temperatures in excess of 35◦ C. These temperatures are characterized as being practically intolerable. There is a difference between normal and wet-bulb temperatures. United States infantry are said to have been exposed to temperatures of 50◦ C (122◦ F) for extended periods of time while wearing body armor during the recent war in Iraq. This gives me reason to wonder at the validity of the temperatures cited. None of this changes the mute fact that there are very real limits to what human beings can tolerate.
Patrick
It’s distracting when/if it’s noticed; I didn’t notice that number the first time through (glazing after hearing too much familiar info?) but after you pointed it out I listened back to what didn’t really sound like a miscue. A careful listener will be arrested by that number and then of course will wonder about everything else in the talk.
Might ask David himself; he’s got a comments thread on this at his blog.
I think I see where that high number came from: It’s a dry-bulb equivalent or perhaps a heat index figure. From the linked WP page:
“Outdoors in open conditions, as the relative humidity increases, first haze and ultimately a thicker cloud cover develops, reducing the amount of direct sunlight reaching the surface. Thus, there is an inverse relationship between maximum potential temperature and maximum potential relative humidity. Because of this factor, it was once believed that the highest heat index reading actually attainable anywhere on Earth is approximately 71 °C (160 °F). However, in Dhahran, Saudi Arabia on July 8, 2003, the dewpoint was 35 °C (95 °F) while the temperature was 42 °C (108 °F), resulting in a heat index of 78 °C (172 °F). This is comparable to the temperatures that are recommended to kill bacteria in many meat products and it is common in a sauna.” (Emphasis added.)
I suspect Dave may have been mixing a dry-bulb apple with a heat index orange in the figures he cited, but if so that’s an understandable conflation given that he wasn’t reading from a prepared text.
Thanks for tracking this down
Somewhat off-topic, I suppose, but Paul Krugman’s latest TNYT op-ed is quite good. Clearly the powers-that-be are out of touch with reality. That includes the Chinese powers-that-be after reading China’s latest coal plan.
The first commenter above has the right of it, I fear.