terra central

A Tragic Ignorance of Mineral Weathering

Rainwater harvesting offers a safe alternative to arsenic-tainted groundwater.

Following up on a report from the British journal Lancet, global news agency AFP reports:

“Up to 77 million Bangladeshis have been exposed to toxic levels of arsenic from contaminated drinking water, and even low-level exposure to the poison is not risk-free, The Lancet medical journal reported.

By some estimates, between 35 and 77 million people in Bangladesh have been chronically exposed to arsenic-contaminated water as a result of a catastrophically misguided campaign in the 1970s.”

The “misguided campaign” had the good intention of providing safe water to millions of people living on the vast, low-lying Ganges–Brahmaputra River Delta. The delta receives drainage and sediment from the Himalayan mountains and, due to the wet tropical climate and relative solubility of arsenic-containing soil minerals, the groundwater is contaminated.

Rainwater harvesting is an inexpensive, sustainable alternative to using tainted groundwater for drinking. Expanded use of rainwater harvesting with simple technological enhancements to improve on an ancient practice is showing good results. The problem seems to be difficulty expanding the program fast enough.

Bangladesh, squeezed between the mountains and the sea, and most of which is less than 40-feet above sea level, has the coastal problem of saltwater intrusion into surface freshwater sources. Here is an interesting video on that topic and efforts to build more rainwater harvesting systems.

Further information on Rainwater Harvesting

Coast of Alaska: Accelerated Erosion 2002-2007

Alaskan coastal erosion (USGS).

A five-year study in Alaska led by the U.S. Geological Survey (USGS) found that shoreline erosion along a 40-mile stretch of the Beaufort Sea has been accelerating from about 20-feet per year fifty years ago, to 45-feet per year by 2007. The research makes obvious the importance of considering the specific properties of the earthen materials exposed to erosive forces. In this case, the land contains permafrost, a consituent of the soil order called Gelisol.

An excerpt:

The authors proposed that these recent shifts in the rate and pattern of land loss along this coastline segment are potentially a result of changing arctic conditions, including declining sea ice extent, increasing summertime sea-surface temperature, rising sea level, and increases in storm power and corresponding wave action.

“Taken together, these factors may be leading to a new era in ocean-land interactions that seem to be repositioning and reshaping the Arctic coastline,” wrote (Benjamin) Jones and his colleagues. “And any increases in the current rates of coastal retreat will have further ramifications on Arctic landscapes – including losses in freshwater and terrestrial wildlife habitats, and in disappearing cultural sites, as well as adversely impacting coastal villages and towns. In addition, oil test wells are threatened.”

Alaskan permafrost erosion (USGS)

For most of us who live on the relative “terra firma” of the mid-latitude continents, global warming may seem like a fairly benign process, one that might result in better weather to play golf. The Arctic and Antarctic environments, by contrast, are very different, very fragile worlds. The authors are careful with their words, using the standard qualifiers, but it’s pretty clear they think climate change is a factor as the waves pound that coast.

Research Paper:
Jones, B.M., Arp, C.D., Jorgenson, M.T., Hinkel, K.M., Schmutz, J.A., and Flint, P.L. Increase in the rate and uniformity of coastline erosion in arctic Alaska. Geophysical Research Letters, February 14, 2009. http://www.agu.org/journals/gl/gl0903/2008GL036205/.

Photos source: USGS

More Sandbags: Fargo-Moorhead Braces for Major Flood

For the second year in a row, soils, geomorphology, and snowpack set up a major flood risk.

The Red River of the North has “issues” that tend to make life “interesting” for those who live near it and depend on it. The Red is a fairly small river in a large watershed. The Red River Valley is not really a river valley at all, but a broad, flat lake bottom formed by Glacial Lake Agassiz.

The fertile soils of the Red River Valley developed from clayey (smectitic) glacial drift largely derived from the Pierre Shale. These sediments, known as the Sherack Formation, are parent materials for the widespread Fargo silty clay (Fine, smectitic, frigid Typic Epiaquerts). These soils are poorly drained and the high-activity smectite clay shrinks and swells as it wets and dries. The force of the expanding clay soil has no problem cracking basement walls. Excavating around foundations, straightening and bracing basement walls is a good business in Fargo-Moorhead. If you want to sell a house, get ready for a building inspector to tell you to fix your foundation.

Because the Red River flows north, it tends to thaw first at the south end and ice-jam at the north end, causing water to back up at the south end of the valley. Post-glacial isostatic uplift is greater at the north end of the valley, where the glacial ice was thicker, so the valley is gradually tipping north to south, from Pembina toward Wahpeton. As the estimable North Dakota State Geologist John Bluemle writes

Because the amount of uplift was so much greater at Pembina than it was in the south at Wahpeton, the gradient of the Red River has decreased markedly since its route became established. Since Lake Agassiz drained from North Dakota about 9,000 years ago, the Red River has meandered over an increasingly broad floodplain. Flooding is a recurring problem along portions of the Red River.

So, because the diminished river gradient caused by isostatic rebound tends to back water up at the south end of the valley, and ice jams up north partially block river flow, and the clay-rich soils plowed and left bare over the winter let snow melt run off like soup on a plate, Fargo-Moorhead gets ready for another flood.

And the flooded fat clays in the soil will crack more foundations, and the basement walls will crack and leak, and the wall-jacking contractors will have work again next summer.

Summers are real nice out there.

Put Livestock Back Out to Pasture

Grazing livestock would enhance soil fertility, raise healthier animals, and improve public health.

“…an estimated 70 percent of all U.S. antibiotics and related drugs are given to animals that are not sick. This overuse of antibiotics contributes to the development of antibiotic resistant bacteria, with the result that antibiotics we commonly use are becoming less effective in fighting human illnesses, including some life-threatening infections.” - Union of Concerned Scientists

In the above photo, courtesy of EPA Region 8, the steel storage bins in the background hold corn for the cows. Corn is hard on the bovine digestive system, which is designed for grass. I’ve seen these kinds of “cow cities” in eastern Colorado and Texas. The business model depends on cheap corn, which puts weight on the cows much faster than green, low-carb grass.

The ground beneath the cows is actually a huge pile of manure. If one views the larger image, it’s apparent that many of the cows are sitting or lying down. That doesn’t necessarily mean they are sick, but that still looks like a lot of cows down.

The implications of this kind of factory farming extend well beyond the aesthetic to a serious public health issue. Antibiotic resistence is recognized as a major problem in treating major diseases such as MRSA, tuberculosis, staph, strep, malaria, typhoid fever, and others. Source: Center for Disease Control.

There is an alternative to this kind of beef. Grass-fed beef is available and found with a bit of searching. Information on producers by state is available from AmericanGrassFed.org and LocalHarvest.org

An additional benefit of growing perennial forage crops, or hay fields, is soil carbon capture and sequestration (CSS). With less plowing of the soil, more soil organic carbon derived from root decay and micro-organisms remains in the soil.

The era of big CAFOs really needs to be over.

Ocean Phytoplankton and Climate Interactions

“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.

A Song in Praise of Bums and Mountains

Big Rock Candy Mountain

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

Happy (Dirt) Trails…

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.

Globalized Agriculture and Third-World Farmers

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.

Soil: The foundation of the economy

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.

Soil at the Center of the Environment: Part 1

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.