“Sustainable” isn’t sustainable. It isn’t even achievable, according to several researchers presenting at the annual meeting of the American Association for the Advancement of Science. Global carbon emissions have accelerated so dramatically over the last eight years, we are “now outside the entire envelope of possibilities” reviewed by the IPCC. Sure enough, sea levels are rising and rising faster than predicted. Meanwhile, biofuels, the great green hope of so many, have only made things worse, leading to a increase in slash & burn farming in the tropics. Indeed, we could find ourselves “effectively burning rain forests in our gas tanks,” noted one scientist.
TrackerNews has been full of stories over the last few months painting the same grim picture:
- The Sea of Japan absorbs only half has much CO2 as it used to. Scientists suspect warmer water temperatures have changed the pattern of vertical currents known as “ventilation.” The water on top has essentially become saturated with CO2. If it turns out this is happening in other oceans, the ramifications are immense. Oceans absorb about a quarter of human-generated CO2
- All this CO2 is making the oceans more acidic, which is destroying coral reefs, along with anything else unfortunate enough to rely on a calcium carbonate shell. That, in turn, is making it more difficult for stressed fisheries to recover, leading to higher food prices and hunger. The circle may be even more vicious. Researchers have just discovered that fish play a key role in marine carbon sequestration. Fish excrete vast quantities of calcium carbonate as a result of drinking seawater. Scientists speculate that climate-warmed seas would speed up fish metabolism leading to increased excretions. But fewer fish means a net decrease and less calcium carbonate in the water to neutralize acidity.
- Canadian forests are now carbon emitters. A combination of drought, logging, beetles, milder winters (warm enough to allow beetles to survive) and fire have turned 1.2 million square miles-worth of carbon sink solution into part of the problem.
Clearly, if we are going to make any headway with this disaster, we are going to have to come up with goals considerably bolder than “carbon neutral.” Optimistically, we are thisclose to an irreversible tipping point. According to yet another depressing study, global warming could trigger massive marine “dead zones” persisting for thousands of years.
BIOCHAR, a.k.a. AGRICHAR, a.k.a., TERRA PRETA: OLD TECH TO THE RESCUE
Soil holds more carbon than the combined totals of the vegetation than grows in it and the atmosphere above it. And soil laced with biochar, a special charcoal made in a low oxygen burn, is particularly good at sequestering carbon. It also reduces nitrous oxide emissions, which is significant because molecule for molecule, nitrous oxide packs about 300 times the greenhouse gas punch as CO2.
That’s not why pre-Columbian Amazonians, who were the first to figure out how to make it, liked it. Bichar improves soil fertility. Its porous structure provides an inviting matrix for microbes and nutrients. It holds water more efficiently. Rootlets and other soil dwellers have an easier time navigating the depths.
Pockets of Terra Preta can still be found in South America – soil that is strikingly black amidst washed out, nutrient-poor rain forest dirt. Even after thousands of years, it still hold its richness and ability to sequester carbon. In short, biochar is a proven long-term option for reducing atmospheric carbon, with the added bonus of improving crop yields.
Tim Flannery (“The Weathermakers“) suspects it may be “the single most important initiative for humanity’s environmental future,” while James Lovelock (“The Revenge of Gaia“) suspects it may be our only chance:
So are we doomed?
JL: There is one way we could save ourselves and that is through the massive burial of charcoal. It would mean farmers turning all their agricultural waste – which contains carbon that the plants have spent the summer sequestering – into non-biodegradable charcoal, and burying it in the soil. Then you can start shifting really hefty quantities of carbon out of the system and pull the CO2 down quite fast.
Would it make enough of a difference?
JL: Yes. The biosphere pumps out 550 gigatonnes of carbon yearly; we put in only 30 gigatonnes. Ninety-nine per cent of the carbon that is fixed by plants is released back into the atmosphere within a year or so by consumers like bacteria, nematodes and worms. What we can do is cheat those consumers by getting farmers to burn their crop waste at very low oxygen levels to turn it into charcoal, which the farmer then ploughs into the field. A little CO2 is released but the bulk of it gets converted to carbon. You get a few per cent of biofuel as a by-product of the combustion process, which the farmer can sell. This scheme would need no subsidy: the farmer would make a profit. This is the one thing we can do that will make a difference, but I bet they won’t do it…. (“We’re doomed, but it’s not all bad”)
NEXT STEPS
"This book, I believe, provides the basic information required to allow implementation of the single most important initiative for humanity's environmental future" Tim Flannery
Interest in biochar has increased over the last few years, though it is still mostly soil scientists talking excitedly to one another. The International Biochar Initiative, chaired by Cornell’s Johannes Lehmann, has helped focus efforts. There are currently research projects in nine countries, several conferences on the calendar and a new book due out in March.
Yet the big dollars for underground carbon sequestration about going into drilling projects. The U.S. Department of Energy has spent nearly a half billion dollars trying to figure out how to inject CO2 from coal plant smokestacks into rock deep beneath the surface — with precious little to show for it so far.
Imagine if that money had been invested into wind, solar, geothermal, smart grids and biochar. Reduced emissions. Increased carbon sequestration. Let’s aim for carbon negative! Given the alternative, it certainly seems worth a try.
So tell your friends. Tell everybody. Biochar: better climate through charcoal.
* related post: Matchmaking: On Soil, Lost Ideas, Terra Preta, Carbon Sequestration and Amy B. Smith
(*twitter-friendly url: http://tinyurl.com/crxs72)
