Dust and Soot

This article is a timely reminder that dust and soot impact hugely, although both are actually been progressively tackled as global industrialization advances. The richer our economy becomes, the less willing we are to tolerate having smoke blowing in our faces. China and India are no different. The yelling has already started and the polluters are slowly responding.

Cleaning up our own house is the easy part. Even converting all of humanity into manufacturers of terra preta is also easy. It can even happen rather quickly and certainly within a lifespan, thanks to the communication revolution.

What is not so easy is cleaning up nature’s house. The global desert needs to be covered in vegetation in order to end the constant mobilization of dust into the atmosphere. This will take technology and sustained investment. Again I have described some of the how, but as yet there is little will.

The other monkey on the global back is the constant threat of a massive volcanic eruption. This is an event that at best wreaks growing seasons for at least two seasons by filling the atmosphere with volcanic dust and gases.
A globally unified reserve system needs to be in place in which long lasting staples maintain a long inventory train. It would entail a global treaty in which designated food stuffs must be warehoused for two years before sale.

This pushes the cost out onto the market, yet ensures a very long train if a major disaster occurs. It goes without saying that this also cushions localized disasters. A drought in the Midwest would be countered by a drawdown of warehoused stocks, to be quietly rebuilt over the succeeding years as fresh crops come in.

It also must be a global decision because the real costs of sustaining inventory must be bourn by all.

Dust plays huge role in climate change

Tiny particles heat up the atmosphere faster than scientist once believed. The good news is this dust can be cleaned up fairly quickly.

By Robert C. Cowen Columnist
from the April 3, 2008 edition Christian Science monitor

Science columnist Robert Cowen talks about atmospheric dust and its effect on climate.

Scientists know that dust affects climate. Tiny particles create veils that reflect sunlight and cool the atmosphere. Dark particles absorb sunshine and warm things up. But as scientists look deeper into the dust-climate connection, they find that they have underestimated its importance.

Research published April 3 in Nature reveals the tight linkage between atmospheric dust flows and Antarctic temperatures during ice ages over the past 800,000 years. A research review published March 23 in Nature Geoscience online shows that black carbon particles in the atmosphere have a more powerful global-warming effect than any of the greenhouse gases except carbon dioxide. And these particles are 60 percent as effective as CO2 itself. That's far more powerful than the estimate in last year's report of the UN-sponsored Intergovernmental Panel on Climate Change (IPCC).

The good news is that black carbon particles such as diesel soot or wood-stove smoke only stay airborne for weeks. (It takes a century to get rid of today's CO2 emissions.) This fact offers an opportunity for instant payback, say study authors V. Ramanathan at Scripps Institution of Oceanography in San Diego and Gregory Carmichael at the University of Iowa in Iowa City. In an announcement from Scripps, the authors note that commercially available technologies exist to cut back soot emissions substantially. Using them would rapidly reduce black-carbon warming.

Dr. Ramanathan explains that the difference between the study estimate of the sooty warming and that of the IPCC is the difference between inadequate computer modeling and actual observation. The Carmichael-Ramanathan estimate integrated data from satellite, aircraft, and ground instrumentation. This shows a black-particle warming of 0.9 watts per square meter. The IPCC estimate was between 0.2 and 0.4 watts per square meter.

In China and India, home cooking with wood and cow dung in addition to home heating with coal contribute 25 to 35 percent of the global atmosphere's black particle burden. Areas that use a lot of diesel fuel contribute comparable amounts. Ramanathan says the next phase of this research is "to examine if black carbon is also having a large role in the retreat of arctic sea ice and Himalayan glaciers."

Meanwhile, Fabrice Lambert at the University of Bern in Switzerland and colleagues are taking advantage of an unbroken 800,000-year climate record in an Antarctic ice core to track dust flows into the region. They find what they call "a significant correlation" between dust coming into the region and Antarctic cooling. They suggest that the 25-fold increase in dust inflow they see during glacial times relates to stronger South American dust sources. Also, less rainfall during those times allows dust to stay airborne longer than when more abundant rain washed it out. It's what the research team calls "a progressive coupling of the climates of Antarctic and lower latitudes" during glacial times.

Such results show that climate modelers need to take careful account of dust in their climate change scenarios. So, too, should the delegates from 163 countries now meeting in Bangkok, Thailand, as they schedule the drafting of a new global-warming mitigation agreement. They might find the prospect of a quick payback from curbing black-particle emissions attractive.

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