Ancient Technologies Revived to Combat Climate Change

October 15, 2010 (GreenAnswers) – As European explorers made preliminary excursions through Brazilian waterways in the late 1800s, they noticed something puzzling about the surrounding land. Brazil’s characteristically uniform red soil beds, too dense and claylike for most manipulable agriculture, was punctuated with beds of dark, fertile soil. What could possibly account for this unprecedented irregularity?

Scientists among the European exploration teams hastened to come up with explanations for Brazil’s unorthodox soil patterns, which they named terra preta. Some hypothesized that the fertile black soil was the widespread remnant of a massive dead lake. Others postulated that it was due to pockets of volcanic ash, absorbed into the soil after centuries of occasional volcanic activity. Unable to hold up to the scrutiny of modern science, these explanations eventually faded into historical obscurity, and the issue of Brazilian soil irregularity was put on the backburner of the scientific community. Until now. Resident soil scientist at Cornell University, Johannes Lehmann, recently took up the mystery of terra preta, and has come up with an answer that he thinks not only answers the question of the black soil’s origins, but also gives us a valuable tool for reversing climate change.

While studying in Brazil in 2003, Lehmann worked with teams of resident anthropologists and came to the conclusion that terra preta could not be explained by natural phenomenon. Instead, Lehmann concluded that ancient Amazonian farming civilizations must have turned miles of red clay soil into fertile black soil by systematically burying ultra-rich carbon deposits in the earth. His claim supported by archaeological and chemical evidence, Lehmann set out to prove his theories further through a series of farming studies in the neighboring South American country of Colombia.


An example of a terra preta field in Brazil

Lehmann’s first order of business was to produce the concentrated carbon necessary to test this ancient technology. He wanted to do this by using a contemporary chemical process he’d been testing as a way to solve a very modern scientific query: how can we dispose of organic matter without releasing heat-trapping greenhouse gases into the atmosphere? Normally, when organic matter breaks down, it enters into a carbon cycle, releasing carbon emissions as it decomposes. These emissions then become pollutants, locking heat into our atmosphere, providing the impetus for global climate change. Lehmann sought to short-circut the carbon cycle by using a technique called pyrolysis, a way of heating organic matter without using oxygen. The process results not in gaseous byproducts but instead in solid carbon that gets trapped inside black chunks of charcoal-like material.


A handful of biochar ready to be deposited into farm soil

This carbon byproduct, known as biochar, was used in Lehmann’s Colombian farming experiments and produced fantastic results. The study proved that soil enriched with biochar produced up to 140% more agricultural product (in this case, corn) than ordinary gardening soil. This is because biochar, once introduced to the host soil, acts like a huge carbon sponge, holding in both moisture and nutrients to boost overall crop yields. Not only that, but the solid carbon deposits seem to be a highly stable additive; calculations taken from samples in the ancient Brazilian black soil show that carbon deposits have remained active in that soil for centuries, and possibly for as long as eight thousand years.

For Lehmann, biochar represents a scientific breakthrough that could very well be the key towards producing climate change. Biochar production could reduce carbon emissions by turning organic matter into a usable alternative product. Not only that, but biochar could be used to stimulate forest replenishment, accelerating the growth of carbon-absorbing trees while producing zero carbon itself. This has the potential to radically decrease overall carbon levels; Lehmann’s initial calculations show that producing biochar from just 120 million hectares of US farmland could shrink the nation’s annual carbon emissions by ten percent. Biochar technology can also be used on a smaller scale in the developing world. As a cheap and efficient stove fuel, widespread biofuel distribution in Africa and Central Asia could both slow rural deforestation and reduce the rates of sickness and death caused by the toxic fumes released by traditional charcoal cook stoves.

All of these options are certainly plausible now that both the public sector (through the US Department of Agriculture) and the private sector (through a wide-range of bioenergy companies hoping to become carbon-negative facilities) have begun investing in biochar research and development, an important step towards reviving this ancient technology to solve the problems of the modern age.

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Dwindling CA Sea Otter Population Linked to Deadly Bacterial Strain

Yawning Sea Otter

A sea otter lounging in Monterey, CA

Sep 29, 2010 (GreenAnswers) – Historically, sea otters have had a rough time living off the warm coastal waters of Southern and Central California. During the Western expansion characteristic of 19th century America, California sea otters became an unfortunate victim of the burgeoning fur trade, their population dwindling down to nearly nothing by the start of the 1900s. However, following their dramatic rediscovery on an inlet of Big Sur in 1939, the species benefited from extensive efforts made to study and rehabilitate it, and sea otters have been making a steady comeback in California ever since. Until now.

The US Geological Survey recently confirmed a 3.6% drop in California’s sea otter population for 2010, with an even more alarming 11% drop in sea otter pups born this year. This marks the second consecutive yearly drop in sea otter population, something that worries Tim Tinker, head of the USGS otter research program in Santa Cruz, California.

“All the research we have done to date suggests there’s no one single mortality factor,” Tinker says, “but that the deaths are caused by a suite of interacting stressors”. Tinker cites several natural causes for increased sea otter deaths (low genetic diversity; parasites from feral animal excrement; recent increases in shark attacks) as well as distressingly standard human causes (dirty ocean water from urban runoff, agricultural fertilizers, and pesticide traces; poaching; accidental fishing catches).

However, the single most disturbing cause of California’s decreased otter population is a combination of natural phenomenon and human waste. In investigating the irregular deaths of 21 sea otters found off the coast of Monterey, State veterinarian Melissa Miller was left puzzled by a series of chronic liver failures and circulatory problems in young, otherwise healthy otters. Then she found out about microcystin.

Microcystin is an ancient strain of cyanobacteria — a bacterial form of blue-green algae found in large bodies of freshwater. When consumed in large quantities, it causes liver failure and subsequent blood poisoning, which perfectly explained the deaths of the 21 sea otters Miller had examined. The only trouble was figuring out how the marine animals had been exposed to such high levels of an ancient freshwater contaminant.

“Based on what we know, this is the first documentation of a freshwater algal bloom being transmitted to upper-level species mammals,” Miller told the San Francisco Chronicle. She originally postulated that blooms (large formations of bacterial growth in water) of microcystin flowed into the ocean directly from creeks, and was then eaten by urchins and shellfish that were subsequently eaten by sea otters.

Algal Bloom (Lake Erie)

An algal bloom in Lake Erie

To confirm her suspicions, Miller conducted a study with members of the California Department of Fish and Game on the nature of microcystin. To their alarm, they found that cyanobacteria, previously though incapable of surviving for long periods in saltwater, can remain extremely toxic for up to two weeks in the ocean. They also discovered that the poison becomes up to 107 times more concentrated in shellfish, which helps to explain why the microcystin was able to poison Miller’s sea otters so quickly.

The study attributes these changes in the nature of cyanobacteria to changing environmental conditions. Global warming, scientist claim, have raised the temperature of coastal seas and inland freshwater reserves, promoting bacterial growth. This warmer water is also rich in waste-related nutrients as a result of city and agricultural runoff. Warm and polluted water provides ideal living conditions for cyanobacteria like microcystin, and the subsequent flow of these waters into the oceans sufficiently alters marine habitats to accommodate the survival of cyanobacteria for longer than ever thought possible.

All of this leaves Tim Tinker very concerned about not just the future of the California sea otter, but about the future of all oceanic life. “Here is a toxin coming into the ocean,” which, he claims, “probably affects a lot of species, and the first indication we have of it is the death of sea otters.”

For the California sea otter, microcystin represents another deadly concern to their population, something the species doesn’t need; with only 2,711 sea otters left in central and Southern California waters, one disastrous epidemic is all it would take to wipe the species out for good. Even more troubling to concerned marine biologists are the implications this problem has for other oceanic species and the people and industries who depend on them. Steve Shimek, executive director of the USGS’s sea otter research project, commented that “The California sea otter is one of the most researched marine mammals on the planet. So if we don’t have enough information to take action on behalf of the sea otter, I would say that 90% of the other endangered species in the world are doomed.”

Shimek and Tinker plan to concentrate all of their energies into boosting the California sea otter population and figuring out how to most effectively of treating the microcystin problem. “This definitely highlights the importance of monitoring water quality,” Tinker says. “It is an early warning sign for an emerging problem.”


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