2010-10-21 10:23:05Great new review paper on drought
John Cook


There's a great new review paper on drought by Aiguo Dai. I'd love to do a blog post about it but there are so many papers and projects going on, I'm going to have to pass on this one. But anyone else is welcome to have a look and boil it down to a blog post if they like. If you want to get double bang for your buck, there's a skeptic argument "Drought is not caused by global warming" which has yet to get a rebuttal.

Full paper in HTML

Full paper as PDF

Press article about Dai's paper (I like to read these to get good plain English explanations)

Also good example of how a peer-reviewed review paper is written for anyone interested in that kind of thing :-)

2010-10-21 13:29:47


John, that's a rather disturbing paper. 

If I'm reading the color scale right, Australia doesn't look happy in the second half of the century. 

Here in the US, ironically, the regions where disbelief in AGW is strongest (southeast, south central, and parts of the west) are looking to be especially drought-prone in the coming decades.


2010-10-21 19:42:45Climate-change nay-sayers


"Here in the US, ironically, the regions where disbelief in AGW is strongest (southeast, south central, and parts of the west) are looking to be especially drought-prone in the coming decades."

The sooner it shows up, the better. At current rates of political progress, we're going to need a strong "hint" from reality to push through the nay-sayers. On the physical level: We're going to have to hope that somebody can speed up the extraction of CO2 from the atmosphere; unfortunately, I suspect that will be pretty expensive, unless the new Tea-Party Congress finds some way to repeal the laws of thermodynamics. 

2010-10-22 04:44:58blog post
Dana Nuccitelli
Definitely an interesting review paper.  I might do a blog post on it this weekend, unless somebody else gets to it first.
2010-10-22 08:26:55
Mark Richardson

Be careful with precipitation projections: they're still getting them wrong in places!

I know someone working on CMIP5 (they basically compare different climate models) and I'll ask him if he can point out some good papers showing this.


I went to a presentation where they used a new method to calculate climate model precipitation and they had interesting results: they're pretty good over northern hemisphere land where rainfall is dominated by moving air masses. But where convectional rainfall dominates they don't seem to do as well. There's also a problem with some expectations of circulation change because they don't fully capture convectional rainfall, especially in the tropics and around Indonesia (for e.g.) where the huge latent heat releases in the atmosphere drive circulation and can affect rainfall patterns thousands of miles away.

So I suggest caution when reading regional precipitation projections! Even when models seem to give the right total amount, they often seem to drop lots of it in the wrong places. (at least, the older ones did, not sure about the CMIP5 ones)


Although I'm currently writing an article using projected changes in snowfall so I suppose I should just shut up.

2010-10-22 08:43:09
Rob Painting

Dana, also have a look at this paper:


Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009

Maosheng Zhao* and Steven W. Running

It would make a good follow up post, demonstrating it ain't all about projections, it's happening now. Note the drying trend is in the warmer Southern Hemisphere where mean annual temperatures for vegetated areas is some 12 degrees C higher than the Northern Hemisphere.

2010-10-22 15:08:07pass
Dana Nuccitelli
Actually I take it back, I don't think I'll have time this weekend, and Joe Romm did a thorough job discussing this paper on CP already anyway.
2010-10-22 15:12:50


In the "happening now" department, check out Hoover Dam:



That's the bit of the dam w/-vertical- walls, not the easily dramatized low-slope upper reaches.

Perspective on this from the fellow who took the pictures, John Fleck:


2010-10-22 19:16:18
Rob Painting
Doug, I remember reading a National Geographic article on the dams a year or more back. It's trouble a brewin' alright. One really does have to marvel at the sheer genius, and sheer stupidity of humans.