Watts confuses local with global - yes, again!
Watts once again confuses average global temperature with local temperature. Now you might say, what's new about that. This time he writes about a video mix including some of a Ted talk, in which David Roberts points out that if we don't cut CO2 emissions enough soon enough, more places will get too hot for people to survive there.Roberts speculates that if average surface temperature rose by 12°C, places that today average around 80°F would then average 180°F. (I don't know if that's correct or not. I do know that humans would find it impossible to survive in more and more places if we pushed global surface temperature up by 12°C.)
Anthony misrepresents the segment, acting as if Roberts is talking about a global average surface temperature of 180°F. In fact Roberts was talking about a global rise of 12°C leading to some places getting as hot as 180°F. Anthony even puts up a chart of global temperatures with a spike going up to 95.5°F - yeah, really!
Did he understand that Roberts was talking about local temperatures? It depends on whether he has a brain and is a professional disinformer, or if he's as clueless as he pretends to be and is one of the 8%. So far none of his commenters have picked him up on his 'mistake'.
My advice to Anthony: run your articles by your dog Kenji before you post them.
How hot does it get today?
I went exploring to see just how hot some places get today and found this page, where temperatures at Flaming Mountain in China are thought (by some) to have reached 175°F. That's nearly 80°C. As the NASA article points out, there aren't too many weather stations in the world's most inhospitable places.In Australia, the hottest official temperature ever recorded is 50.7°C at Oodnadatta.
I freely admit to not having read the WUWT stuff, but surely the underlying point is at what temperature (globally averaged and regionally expressed) does current NH mid-latitude agricultural production collapse?
ReplyDeleteI haven't yet watched the TED video in question, but I'll bet dollars to doughnuts that Roberts was talking about a *heat index* (temperature/humidity combo) of 180 degrees.
ReplyDeleteGiven that paleoclimate evidence shows that sea surface temperatures exceeded 100F during the high Eocene, such a number is quite plausible.
A sea surface temperature of 100F means that you could easily get dew points in the neighborhood of 100F -- and a 100F dew point gets you pretty close to a 200 degree heat index.
Anyone caught outside in conditions like that would die of heat stroke in a matter of hours.
Paleoclimate evidence and a basic understanding of the limits of human heat tolerance tell us that a BAU fossil-fuel policy could very well render much of the world uninhabitable by humans in the next century or two.
--caerbannog
Caerbannog - welcome :D
DeleteDavid Roberts was talking about what earth will be like at 2, 4, 6 degrees and hotter.
The point Anthony Watt's wrote about (and got so wrong) was about was the possibility that if we push temps up by, say six degrees, other positive feedbacks will kick in and the global temp could eventually go up by 12 degrees C, meaning half currently inhabited land would be too hot for us and some places would be hitting 180 degrees F. Not impossible. Anthony confused local temps of 180 degrees Fahrenheit with global (which could happen at global temp of 12 degrees Celsius). (Wet bulb temp would be lower than 180 F but still kill you.)
(We can probably blame mixing degree scales, C and F, on the US audience, where Celsius isn't yet standard.)
I'll repeat the link to the video clip to save people having to go to WUWT. (Bear in mind it's a Grist-blogger's interpretation of the science for a general audience.)
http://www.youtube.com/watch?feature=player_embedded&v=pznsPkJy2x8#!
He's done another doozy yesterday, in which he appears to completely misunderstand the analysis that was used to estimate changes in rainfall patterns.
ReplyDeleteWillis has had some awesome cockups up there lately too. THey really are a carnival of stupid!
Yeah - I don't know if there are no farmers left who still deny climate science or if the ones that do just don't bother commenting.
DeleteI sometimes wonder if there is a denier out there who appreciates any of the finer points of rainfall (or if they are all city-dwelling latte-sipping luddites :D)? - what makes a drought a drought, why intensity and seasonal patterns matter, the damage floods and droughts can cause, why on our warmer earth the extra water falling won't always be a 'good thing'.
" Roberts speculates that if average surface temperature rose by 12°C, places that today average around 80°F would then average 180°F. "
ReplyDeleteHow did Watts get it wrong? You state right here that the places would average 180 F, not spike to, but average 180 F.
I've gone back to Watts' article. What he's done is assumed that everywhere on earth would rise by the same amount. He's done a simple projection up from 60°F (global average temperature) and said it's impossible for earth to heat up by 18.6°C therefore it's impossible for places currently 80°F to get to 180°F. But that doesn't follow. You can't simply add a number to the global temperature and say that every place on earth will rise in temperature equally.
DeleteIf some areas in a broiling world (after a rise of 12°C) had a temperature of 180°F then the average global surface temperature would still be up by 12°C, not 100°F.
Now as I said in my article, I don't know if Roberts was speaking from an informed basis or if he was exaggerating a tad. However it's certain that parts of the world would heat up at different rates to other parts. Not every place in the world is heating by the same amount (some places aren't getting hotter at all yet, and some are even getting cooler while the world as a whole is getting hotter). In any case, that's not the point. The point is that Watts jumped straight from global temperatures to local temperatures and equated the two.
Below is a link to the article Roberts was basing his 12°C speculation on, which in turn is a comment on the Sherwood and Huber paper I linked to in my main article.
http://www.pnas.org/content/107/21/9483.full