I didn’t have a chance to do a story for the newspaper on the new Science paper by Westerling et al.[1] on wildfires and climate change, so I just got around to reading it this evening.

In a sense, it seems like a bit of a no-brainer. Common sense would suggest that when temperatures are warmer, stuff burns up more easily. But the fire story in the western United States is hugely complicated by the ecosystem effects of more than a century of fire suppression and land use changes (grazing especially), so common sense is a poor guide here, and data seems better. In this case, the data sheds some important light on the sort of question Roger Pielke Sr. keeps harping on as an important goal of relevant climate research: the effects of climate change and variability on “regional and local societal and environmental resources of importance.”

Continue reading ‘Wildfire and Climate Change’ »

Interesting El Niño forecast out today from the Climate Prediction Center:

Most of the statistical and coupled models predict slightly positive SST anomalies (ENSO-neutral to weak El Niño) in the Niño 3.4 region through the end of 2006. These forecasts are consistent with the recent build up in upper-ocean heat content along the equator.

I wouldn’t start buying stock in New Mexico ski areas just yet, but it’s the first ENSO-positive forecast, with the models starting to spread upward toward an El Niño this winter (that favors wet weather here in the southwest U.S.).

0.58 inch after midnight at my house, most of it between 4:30 and 5:30 a.m. Out at the airport, the National Weather Service got 0.69.

One of climatologists’ predictors of whether or not we’re going to have a big monsoon is the date of onset. Early onset generally means a wetter monsoon.[1] We’ve got no crisp definition here in Albuquerque (and, in fact, the monsoon onset isn’t very crisp here), but in Tucson they’ve developed a very precise definition based on dewpoints. Their start was June 28, nearly a week early. Compare that to the onset since 2001, when they had a late start all five years and a lousy monsoon four out of five years. I’m comparing apples to organges by using the Tucson start date, because that isn’t the definition used in the paper I cite below. And the actual correlations between Tucson’s onset date and total monsoon rainfall, either there or here, are so weak as to render the above discussion irrelevant. So it’s not science, just blind optimism.

Last year we had a false start in late June, and then things dried up. But we’ve got rain in the forecast for the next week.

[1] Interannual Variability of the U.S. Summer Precipitation Regime with Emphasis on the Southwestern Monsoon, R. W. Higgins and K. C. Mo, Journal of Climate: Vol. 11, No. 10, pp. 2582–2606

Going through some papers on my desk, I ran across this quote scribbled on a piece of paper:

Many droughts will occur; many seasons in a long series will be fruitless; and it may be doubted whether, on the whole, agriculture will prove remunerative.

That’s John Wesley Powell describing life in what he called the Arid Region, the lands west of the 100th meridian where rainfall averages less than 20 inches (~51 cm) per year. Less than that and it’s tough to make a go of it without irrigation, but Powell understood back then that you have to think about more than the annual average. What matters, he realized early on, is not only the mean but the variability around that mean.

It’s difficult to view Powell through the lens of history. We in the western U.S. tend to see our own ideas reflected in his. For me, it’s easy to imagine him now looking at the bungle we’ve made of things and saying, “I told you so.” But he did. His Report on the Lands of the Arid Region is amazing. Bernard DeVoto called it “One of the most remarkable books ever written by an American.”

(The Library of Congress has put the whole thing on line, and William deBuys included lengthy excerpts, along with a great introductory essay, in his collection of Powell’s writings.)