terra central

“Give me a half a tanker of iron, and I’ll give you the next ice age.” - John Martin, Oceanographer

For over a decade, fertilizing the oceans with iron, an important plant nutrient, to create algal blooms has been proposed and demonstrated as a way to capture atmospheric carbon and mitigate global warming.  The carbon-rich algae, or phytoplankton, grow, die, and sink to the ocean bottom where the carbon is stored, or “sequestered.” At least nine ocean-going iron enrichment experiments have been done thus far and the process works.

A NASA satellite image of an algal bloom about 100-miles (150km) created by one iron enrichment experiment is shown here.

Photo source: NASA and CSA

But it turns out the phytoplankton have still another strong environmental effect: the production of cloud-seeding aerosols.

Evidence shows as the wind sweeps these materials up from ocean waves rich in phytoplankton, the effect is enhanced cloud formation and increased albedo, which reflects solar radiation back out to space.

Does this offer at least a partial fix for global warming? Iron’s cheap and relatively abundant. It could be spread around the ocean on a large scale. The thought of manipulating ocean ecosystems undoubtdedly makes some people nervous, including me. Common sense would go against the notion of fixing one problem by creating another. Then again, we seem to have no problem drastically altering the earth’s land surface through deforestation, agriculture, and urbanization.

But, given that the ocean is 71% of the earth’s surface and probably the primary regulator of earth’s climate, we better be careful with it.

Big Rock Candy Mountain

Music by Harry McClintock, short film by Miss Chelsea Mae, from Tennessee.

And now this:

“Scientists found that exposure to dirt enhances one’s mood and boosts the immune system.”

From Harper’s July 2007, p. 104.

Photo credit: Thibaut Cheytion (Tibo)

Update: 12-14-2007
Received an email from Tibo, who thinks the stripes might be wind-generated. My first impression of the picture had me thinking dune ripples, as well. The odd thing, seems to me, is the thin mantle of vegetative cover on what looks like smooth dune sand. I wouldn’t expect the shifting dune sands to be stable enough for such a uniform covering of moss, or whatever the plant cover is. It might take a another field trip to solve this mystory. Here is a photo of periglacial stripes taken by someone at the University of Regina Geography Department.

In the world of soil taxonomy, the most recently “minted” soil order is the Gelisol order. Gelisols are found in very cold climates that support permafrost. Two major processes associated with Gelisol formation are solifluction (or gelifluction), and cryoturbation.

Solifluction occurs when the saturated (or nearly so) upper part of the soil thaws in summer and flows over the top of the permafrost below, creating low ridges and swales that look like “stripes.”

Since the volume of water expands about 10-percent when turned to ice, cryoturbation is a process of soil mixing, heaving, and buckling due to freeze-thaw cycles. Sometimes frost thrusting creates polygons, such as those shown in the valley here in an earlier post.

The photo above was taken by Thibaut Cheytion (Tibo), a young MBA and CFO of a company in China. Whether he knows it or not, he’s got an eye for soil geomorphology. This photo, I think, shows an especially beautiful example of patterned ground.

Because organic decomposition is slowed by cold temperatures, Gelisols are generally high in organic matter and, therefore, an important global carbon sink.

Photo by Nicksail

No need to feel guilty about growing your own food. On the contrary, you may help peasant farmers keep their sustaining piece of land.

The Environmental News Network picked up this article called Food Miles May Be Green, but Are They Fair? from Reuters. The thrust of the article suggests that the local food movement hurts the Third-World peasant farmer struggling to sell a crop.

Craig Mackintosh’s excellent article Food Miles or Fair Miles is a well-supported argument, essentially “fisking” the ENN and Reuters article. There are also some excellent comments following the article.

For me, the most poignant argument comes from India’s author and activist Verdana Shiva (emphasis mine):

“For those of you who feel troubled that the new certification consideration that food that has been flown in will not be certified by Soil Association, and you are feeling troubled about the farmer in Kenya, or the farmer in India, let me tell you, by the time huge volumes of exports happen in lettuce or beans or baby corn, the farmer is the first to go.

Their land is taken away and put in the hands of agribusiness. An agribusiness through corporate farming does the exports. It’s not peasants. The peasant was finished at the beginning of the process. So in fact by your refusing to add to food miles and add to carbon emissions you are in fact giving protection. You’re not just protecting the atmosphere, you’re protecting a peasant economy.”

Good luck with your gardens, folks!

Remember the best ferilizer is rain.

Craig Mackintosh, who writes at Celsias has a good article called Soil: Our Financial Institution that identifies the soil as the foundation of our physical and even financial well-being.

Without stealing his “thunder,” Craig does a good job of introducing biogeochemical processes in the soil and the potential soil has for sequestering carbon. Incredibly, there is more carbon, globally, stored in soil than in the atmosphere and living vegetation combined.

Craig’s article contains a map of degraded soils worldwide. I don’t want to minimize the role of burning fossil fuels in raising atmospheric carbon dioxide over the last 100-years, but the degradation depicted in the map involves, in part, loss of soil organic matter, which has been lost from either accelerated erosion or decomposition due to regular plowing. Plowing aerates the soil, speeding the process of organic matter decomposition, and exposes the soil to erosive forces.

Oceanographers and climatologists are concerned with ocean acidification. Much of the ocean acidification is due to soil carbon entering the ocean either as sediment or dissolved carbon carried by rivers.

So, you start talking about soil and soon you’re talking about the ocean and atmosphere.

What to do? The key is to use best management practices that minimize erosion. Growing perennial crops is preferable to annuals as perennials do not require working the soil and planting every year. This is one of the reasons that ethanol derived from sugar cane is more efficient than making ethanol from corn. This is why cellulosic ethanol from switchgrass or wood chips is more efficient than ethanol made from corn.

Converting to perennial root-dense grasses (like switchgrass) instead of annual row crops such as corn would also store more carbon in the ground than would be harvested as crops. This would restore some of the carbon to the soil that has been lost over the past 100 years, or so, due to tillage, oxidation, and erosion.

Photo Credit: High Agriculture by Thibaut (Tibo) Cheytion

Soil is an open and dynamic system and supports all terrestrial life, and to a large extent, by providing nutrients in solution, supports aquatic and marine life, as well. This is evident in the high biological productivity found in estuaries, places where rivers meet the sea.

Soil stands at the crossroads of the earth’s vital spheres: the lithosphere (crust of the earth), the atmosphere, the hydrosphere, and the biosphere. All of these “spheres” intersect at the soil.

The soil is derived from the rocks and minerals of the local lithology, or from sediments naturally transported by various means from elsewhere. Lithology leaves a chemical and textural signature on the soil that develops over time, affecting everything that subsequently grows in the soil.

Water moves into the soil from above as precipitation, from below as groundwater, from the sides as seepage from surface water bodies. The soil may release water to all of these places in different ways.

The soil is the “breathing organ” of the earth, cyclicly exchanging gases with the atmosphere.

Soil serves as structural foundation for land plants. Animals, microbes, and fungi living largely unnoticed in the soil carry out complex
biogeochemical processes in plant root zones, making nutrients available to growing plants, and releasing agents of chemical weathering to the soil.

Considering all it does, one might think the “humble soil” of the earth deserves a more sophisticated name, and it does. It is called the pedosphere, the part we touch with our feet.

A note about the photo taken by Tibo, who’s an economist, in Tibet: There are several alpine glacial and periglacial landforms well represented. There are perhaps five aretes, which are straight, sharp ridges between or adjacent four bowl-shaped cirques carved into the sides of the mountains. There is also a U-shaped valley. The relatively young soils supporting crops in the valley look like they are atop ice-wedge poygons derived from glacio-fluvial sediments that are often saturated and undergo frequent freeze-thaw cycles. Polygons are one type of “patterned ground” found near alpine and continental glaciers. Photo used with Tibo’s generous permission.