http://news.yahoo.com/s/livescience/20070625/sc_livescience/arizonadustcausescoloradomeltdown;_ylt=AuwwiV9qLrBLrxi_F.aj9kRpl88F

Perhaps Millet can confirm these findings:


Arizona Dust Causes Colorado Meltdown

By Andrea Thompson, LiveScience Staff Writer
posted: 25 June 2007 03:45 pm ET

Wind-blown dust from the drought-stricken Southwest can speed the melt of snow in Colorado’s mountains, yet another unpredictable effect of climate change, a new study shows.

In 2006, snows in areas of Colorado's San Juan Mountains above and below the tree line (above which trees can no longer grow), unexpectedly melted a month earlier than usual.

The cause for the premature melt was dust, most likely originally from parched deserts in Arizona and New Mexico, hundreds of miles away.

The dust is less reflective than snow and so reduces the overall reflectivity of the area, allowing for more of the sun’s energy to warm, and subsequently melt, the snow pack. A similar effect of dark soot falling on Arctic snow is thought to speed melting there.

“The connection between dust and lower snow reflectance is already established, but the amount of impact measured and modeled in this system stunned us,” said study team leader Tom Painter of the University of Colorado at Boulder’s National Snow and Ice Data Center. “The fact that dust can reduce the snow cover duration so much—a month earlier—transforms our understanding of mountain sensitivity to external forcings.”

There were eight dust deposition events in 2006, up from only three or four between 2003 and 2005, according to the authors of the study, detailed in the June 23 issue of the journal Geophysical Research Letters.

Snowmelt provides one-sixth of the world’s population with drinking water, and is important to sustain agriculture in the western United States.

The expected exacerbation of western droughts brought about by global warming will likely make the situation snowball.

“Recent studies agree that with global warming, the Southwest will be warmer and drier,” Painter said. “Enhanced dust deposition is likely, further shortening snow cover duration.”

“Ultimately, a warming climate and the dust it generates will affect river run-off and soil moisture in the mountains,” he added. “Not only in the Western United States, but across many of the world’s mountains.”

One of the things that we still don't understand is what has happened in the past to draw down the atmospheric CO2 at the end of previous warm periods. The only theory that I have seen that had much support was the idea that iron in dust from the land begins to fuel algal growth in the nutrient rich areas of the ocean.

At the time I got my degree in Marine Science there was a big debate about whether these nutreint rich areas were iron limited, but Martin and Fitzwater actually fertilized a 6 sq mile area with iron and the productivity doubled overnight.

So dust may be one of the factors helping to reduce CO2--the problem is that means large areas turning to desert to supply the dust.

I've read several articles and ecological modeling that the increasing dust storms from global warming from CO2 could trigger massive uptake by those microoorganisms possibly triggering the next ice age. there are other triggers of ice age and global warming proposed, the solar system passes through regions of space where cosmic rays would be lesser or greater than averages for several millions of years as the solar sytem is being swept by the spiral arms of the milky way. the sun could also increase or decrease the intensity and could coincide with global warming or ice ages. also, new and stronger evidences showed that most dinosaurs died of asphyxiation due to lack of oxygen perhaps after the asteriod impact, and that the planet and its life has survived several thousand times more CO2 than what we have now, but triggering massive extinctions of various species... Anyone care for a canister of oxygen? It might be the next great investment, after the bottled water scam which we so foolishly allow ourselves for the sake of convenience, LOL!

Global warming? D'uh.

Joe, I would not know about Arizona dust and Colorado snow. The San Juan mountains in southwest Colorado, do receive tremendous amounts of snow, many times to a depth of 25 to 30 foot deep. The San Juan mountains are absolutely gorgeous, and I would recommend them to anyone for a summer vacation, as they are stunning. For people who enjoy four-wheeling, the San Juan's offer the best in the world. Although I am not a believer in the Global Warming theory, it is true that if snow is covered by any dark substance it does melt at a more rapid pace. - Millet

I'm not certain about the order of the drop in CO2 and the cooling in past cycles-- my impression has been that the cooling came first and that something that happend differently during the ice age causes the decline in CO2.

In any case, the oceans are probably the primary driver of these changes since they are so vast and have the ability to sequester materials by transfering them to the depths.