Sir John Houghton argues that drought is the biggest climate change threat in the developing world:
“It’s the extremes of water which are going to provide the biggest threat to the developing world from climate change,” he said.
“Without being able to be too specific about exactly where, droughts will tend to be longer, and that’s very bad news. Extreme droughts currently cover about 2% of the world’s land area, and that is going to spread to about 10% by 2050.”
I am nothing if not diverse. From this morning’s newspaper:
On U.S. nuclear weapons policy:
Thursday’s announcement is driven by the Pentagon’s Nuclear Posture Review. The 2002 report concludes that nuclear weapons will be with us for the foreseeable future “to deter a wide range of threats, including (weapons of mass destruction) and large-scale conventional military force.”
The current U.S. arsenal— some 5,500 bombs and warheads— is primarily intended to deter Russia’s large nuclear arsenal, according to Daryl Kimball, executive director of the Arms Control Association.
David Cassidy Gets Happy With His Teen-Idol Past:
In other words, “The Partridge Family” was about as un-Hendrix, as un-counter-culture as it’s possible to be when you’re surrounded by guitar amps.
“It wasn’t deep political,” Cassidy said in a telephone interview. “It wasn’t heavy.”
In his ongoing drought series, Daniel Collins had a nice post last week on a trio of studies about the relationship between climate variability and both recruitment and death of piñon, the scraggly little arid pine tree provides our landscape’s signature here (when drought or global warming isn’t killing it).
I’d like to extend the discussion with reference to a paper that came out in 2000 in ecology that sheds some interesting light on what happens at the tree-by-tree scale rather than the landscape scale discusssed in the papers Daniel cited. It’s Tree-ring variation in pinyon predicts likelihood of death following severe drought. The research team, led by Kiona Ogle (at Northern Arizona at the time, now at Wyoming) compared tree rings in trees that survived a 1996 drought and those that died.
One of the characteristics of the arid climate in which piñon live is variability – significant differences between the wet years and the dry years. You can think of it, in statistical terms, as having a large standard deviation relative to the mean. Wet places, say a place like southeast Louisiana, which gets 60 inches (150 cm) a year of rain, have relatively low variability. The driest year on record in the U.S. climate division data for southeast Louisiana saw 66 percent of the yearly average precipitation. Yuma, the canonical dry as dust U.S. city, has huge variability. The driest year in the U.S. climate division data for southwest Arizona (Yuma) was just 17 percent of average. So things living in arid climate have to not only be adapted to less water in general, but also to really dry extremes. Piñon country is arid, having generally high variability.
Life at all scales – organizations, communities, individuals, societies – need the flexibility to handle that variability. Ogle found a clear difference between the trees that lived and those that died. The dead trees tended to have much greater variability in their growth rings, putting on much fatter rings in wet years relative to their dry year rings. I think there’s an important message here, by way of metaphor, for human societies. If you look at societies that have flourished and those that have failed, a distinguishing characteristic is the way they responded to the wet side of the natural range of variability.
Today’s word of the day: paleotempestology
From Miguel, circa 2000
There is much to recommend the nuclear proliferation piece in this morning’s New York Times by Bill Broad and David Sanger. It’s an excellent overview of the situation – how we got here and what can usefully be said about what happens next. I single out the following not because I think it’s the most important issue, but because it highlights a pet peeve of mine:
Democrats and Republicans spent the past week arguing over who lost control of North Korea, Bill Clinton or George W. Bush. But seeds of the problem were planted by President Dwight D. Eisenhower, just months after the armistice ended the fighting on the Korean Peninsula in 1953.
Can we please sidestep the partisan blame game frame? This is important stuff.
paper of the day: When and where might climate change be detectable in UK river flows?: “Even where climate driven changes may already be underway, losses in deployable resources will have to be factored into long-term water plans long before they are statistically detectable. Rather than an excuse for inaction, such insights should inform more sophisticated approaches to environmental monitoring, climate change detection and adaptation.”
word of the day: disgregate – to scatter (hat tip Anu Garg)
music: Joshua Redman’s debut album, which I scored in the used music rack at Natural Sound. A bunch of loving renditions of great classics.
book: Late Victorian Holocausts: El Nino Famines and the Making of the Third World. I don’t actually have the book. I’ve just been poking around in it on Google books. Davis draws some threads between climate variability and political systems that seem very suggestive of some themes I’m interested in, especially with respect to the late 19th century drought that killed so many people in India.
While we’re on the subject of drought, I stumbled on this, by Andrew Heavens, on Flickr. Heavens is a journalist in Ethiopia.
Andrew Dessler hauls out the old dice metaphor for a helpful discussion of why one might take long term climate forecasts seriously even if those silly meteorologists can’t get tomorrow’s weather forecast right:
One simple way to think about the difference in predicting weather and climate is to think about rolling a six-sided die. Predicting the weather is like predicting what the next roll will be. Predicting the cliamte is like predicting what the average and standard deviation of 1000 rolls will be. The ability to predict the statistics of the next 1000 rolls does not hinge on the ability to predict the next roll. Thus, one should not dismiss climate forecasts simply because weather forecasts are only good for a few days.
As a side note, it’s worth noting that the very fact that people notice and remember blown weather forecasts is evidence for how good the meteorological community has gotten. The reason we get annoyed and remember when they get it wrong is that we’ve come to rely on them because, in general, over a few days’ time window, they usually get it right.
Following on Daniel Collins’ discussion of the different measures and definitions of drought, here are a few useful web pages that pull together various indices.
One of the problems Daniel pointed out about my use of the Standardized Precipitation Index is that it only captures precipitation anomalies, which misses the temperature side of the equation. If it’s hotter than normal, you get more evapotranspiration, which makes drought conditions worse. SPI fails to capture that. The standard tool to get around that is the Palmer Drought Severity Index, which also considers temperature. The Palmer was developed in the 1960s as a tool to estimate soil moisture conditions using temperature and precipitation data. Its problem is that it’s such a scary black box that no one quite knows what’s going on inside it – what contributes to a particular Palmer number. It’s widely used, but you will find a lot of people in the drought community who are uncomforable with it. (In fact, that’s why SPI was developed.)
There’s a new tool that’s getting a lot of attention – the Variable Infiltration Capacity (VIC) model. It uses a much more realistic soil-weather-hydrologic system model. Dennis Lettenmaier’s group at the University of Washington is using it to produce regularly updated maps of soil moisture and other variables.
Then at Princeton, Lifeng Luo, who’s working with Lettenmaier, has a web page bringing together a whole bunch of different drought measures in one place. This may be the best approach of all. Given the slippery issue of defining drought, if you’re trying to pay attention to the issue, it’s probably best to look at many different indices and see what overall picture they are painting.
