Birth of a New Wedge

By Kelpie Wilson

t r u t h o u t | Report

Thursday 03 May 2007

Terrigal, New South Wales, Australia - As delegates met in
Bangkok this week to debate climate change solutions contained in the
IPCC's latest report, one technology not mentioned in the draft report
was being closely examined at a conference in Australia in the beach
town of Terrigal, just north of Sydney.

The first meeting of the International Agrichar Initiative
convened about 100 scientists, policymakers, farmers and investors with
the goal of birthing an entire new industry to produce a biofuel that
goes beyond carbon neutral and is actually carbon negative. The
industry could provide a "wedge" of carbon reduction amounting to a
minimum of ten percent of world emissions and possibly much more.

Agrichar is the term not for the biomass fuel, but for what
is left over after the energy is removed: a charcoal-based soil
amendment. In simple terms, the agrichar process takes dry biomass of
any kind and bakes it in a kiln to produce charcoal. The process is
called pyrolysis. Various gases and bio-oils are driven off the
material and collected to use in heat or power generation. The charcoal
is buried in the ground, sequestering the carbon that the growing
plants had pulled out of the atmosphere. The end result is increased
soil fertility and an energy source with negative carbon emissions.

Prominent Australian scientist Tim Flannery, who has
written a book on global warming called "The Weather Makers," was on
hand to give encouragement to the conferees. "I am deeply committed to
your solution," he told the group. In a keynote address, Flannery
provided an update on the acceleration of global warming, from the
rapidly melting Greenland ice sheet to the unprecedented drought that
has gripped Australia.

Because the pace of global warming already exceeds
projections, Flannery is convinced that the world must do more than
just reduce emissions; we must find ways to rapidly remove CO2 from the
atmosphere. According to many researchers at the conference, agrichar
has the potential to store billions of tons of carbon safely away in
soils.

The attendees were clearly excited by this potential, and,
unlike other meetings concerned with climate change, an electric buzz
of optimism was in the air. Joe Herbertson, director of a consulting
company called Crucible Carbon, said, "When I heard about this
technology, the hairs went up on the back of my neck. This is the best
news on climate change I've ever heard."

One reason for the excitement is agrichar's potential to
address a range of problems from poor soil fertility to waste disposal
to rural development. About half the world's population relies on
charcoal for cooking fuel, and the production of charcoal drives
deforestation in Africa and other places. Smoky, inefficient charcoal
kilns pollute the air with noxious gases that harm health and heat the
planet.

An effort to replace these kilns with modern, efficient
pyrolysis units would relieve the pressure on forests by reducing waste
and adding the ability to use any source of biomass, including
agricultural waste products such as rice hulls. The ultimate objective
is to produce enough charcoal to have some left over to bury and
increase soil fertility, leading to a bootstrapping effect where
increased yields provide both more food and more biomass for energy.

Projects discussed at the agrichar meeting ranged from a
household-size pyrolyzing stove that produces both cooking gas and
charcoal, to industrial-scale units capable of processing large waste
streams from sugar mills, pulp mills, poultry farms and even
municipalities.

Some participants suggested that energy, rather than
agriculture, would be the key driver for adopting biomass pyrolysis.
There is a tradeoff between producing energy or charcoal, as the
process can be optimized for either one. Desmond Radlein of Dynamotive
Energy Systems said, "It is wishful thinking that people will switch to
renewable fuels unless it is cheaper. All of this is tied to the price
of oil; as it goes up, many more things are possible." Because it costs
money for transport and the labor to put agrichar into soil, Radlein
feels that the path forward lies with biomass energy plantations
fertilized by agrichar, which will become a self-sustaining loop
pumping carbon into soils, paid for by the energy yield.

Robert Flanagan, an entrepreneur working in China, had a
different view. There are 700 million farmers in China, he pointed out.
China could quickly deploy a small, village-level pyrolysis unit he is
developing, and because labor is cheap, spreading the agrichar on
fields would be affordable even without a large energy harvest.

Others at the conference felt that an expanding market for
carbon credits under the Kyoto protocol would be the force that drives
the adoption of agrichar. Mike Mason, director of the UK biomass
company, Biojoule, said the impact of agrichar on nitrous oxide
emissions alone would be enough incentive to fund the needed projects.

Nitrous oxide is 270 times more potent than CO2 as a
greenhouse gas and it lasts for 150 years in the atmosphere. Use of
nitrogen fertilizers is a major source of the gas, and a difficult one
to mitigate. But agrichar applied to fields seems to have a significant
damping effect on nitrous oxide emissions. Lukas Van Zwieten, a
researcher at the New South Wales Department of Primary Industries,
looking at preliminary results of his field trials measuring nitrous
oxide emissions from agrichar amended soils, said "the more I look into
this, the more excited I get."

Several farmers attending the conference were primarily
interested in the increased yields possible with agrichar. Australia
has some of the poorest soils in the world - 75 percent of Australia's
soils have less than one percent carbon.

The exceptional properties of charcoal in soil were first
noticed in the Amazon where there are large areas of what is called
"terra preta" or Amazonian dark earths. These dark earths can be
several feet deep and contain up to nine percent carbon, as compared
with nearby soils that have only about half of one percent. In one of
the most fascinating aspects of this story, the terra preta soils turn
out to have been deliberately created by a lost Amazonian civilization.
Some of the areas have been dated going back to more than 7,000 years,
and they are still highly fertile.

Field trials and experiments in pots show impressive yield
gains in charcoal-amended soils, but so far researchers don't
completely understand why. One question is whether the effect is
primarily chemical and physical or primarily biological. Charcoal is a
highly porous material that is very good at holding nutrients like
nitrogen and phosphorus and making them available to plant roots. It
also aerates soil and helps it retain water.

Charcoal's pores also make excellent habitat for a variety
of soil microorganisms and fungi. Think of a coral reef that provides
structure and habitat for a bewildering variety of marine species.
Charcoal is like a reef on a micro-scale.

One of the research papers presented at the conference
documented an increased diversity of beneficial microbes in terra preta
soils as compared with unamended soils, but there are still no answers
about whether the fertility increase is due to physical or biological
factors. The best answer may be that it is both.

One very evident tension at the conference was between the
scientists who are trying to better understand how agrichar works, and
the farmers and investors who want to apply the technology as soon as
possible. But one obstacle to deploying agrichar is the ability to
quantify its effects in order to create both a reliable product for
farmers and a solid guarantee of agrichar's carbon-fixing capacity for
the carbon-trading market.

To that end, one of the most important research questions
is how long the charcoal stays fixed in the soil. It's important to
distinguish char, or black carbon, from soil organic carbon that comes
from adding compost, manure or crop residues. According to John Gaunt
of Cornell University, this kind of fresh organic matter does not stay
in the soil but is almost all released back into the atmosphere as CO2
within ten years. For this reason, soil organic carbon has not
qualified as a carbon emissions reduction that would be tradable under
the Kyoto protocol.

Johannes Lehman, also of Cornell, is attempting to
determine what percentage of the char stays fixed in the soil. Some of
it does oxidize, he says, but it's difficult to say how much. He
believes that agrichar-amended soils will see an initial period of
weathering, after which they will be stable for long periods.

Certainly the existence of the terra preta soils in the
Amazon is testimony to the long-term carbon-fixing ability of agrichar,
and several conference participants felt that it would be best to
settle on a conservative amount of guaranteed carbon fixation and move
as quickly as possible to get policy in place to qualify agrichar as a
tradable form of emissions reduction.

The feeling in Terrigal was universal that there is no
time to waste in deploying the agrichar wedge as a global warming
solution.

However, there were some additional cautions sounded about
the potential for abuse, especially the pitfall of all biomass schemes
- the danger that too much of the planet's land will be appropriated
for human needs and not enough left for other species. Mark Glover of
Renewed Fuel said that the source of biomass must be carefully
determined and that it would not do to repeat the mistakes of the palm
oil industry, which is rapidly deforesting the habitat of orangutans in
Indonesia, or the American corn ethanol industry, which has ended up
pricing tortillas out of the reach of Mexico's poor.

Mike Mason of Biojoule expressed concern over the
quantities of biomass needed, but he said that if properly phased in,
agrichar can be the solution we are all looking for. First, he said, we
must take the four billion tons of agricultural waste products produced
every year and turn as much of that as possible into char and bury it
in soils to increase soil fertility. After a few years, as the
productivity of our fields rises, we can begin optimizing biomass
pyrolysis for energy production to help replace coal and fossil fuels.
Eventually, as our energy supply becomes decarbonized and we move more
and more to rely on solar, wind and ocean power, we can shift biomass
utilization back to char again and keep sequestering more carbon to get
atmospheric levels back to pre-industrial levels.

In addition to directing Biojoule, Mason is also the
founder of Climate Care, a highly successful voluntary carbon-offset
program that supports renewable energy projects in the developing
world, so he is one of those visionary people who also knows how to
make things happen.

By the end of the conference, after the participants had
considered the political and economic obstacles to the vision, there
was a bit of sobering up, but not much. Robert Flanagan set up one of
his pyrolyzing wood cookstoves out on the beach and the scientists and
entrepreneurs quaffed beer and roasted marshmallows over the smokeless
glowing coals. Occasionally the stove would belch a sudden puff of foul
smoke and Flanagan would rush to adjust the downdraft control.

After an hour or so, Flanagan opened the stove and dumped a
few chunks of charcoal out onto the sand. Those small morsels of black
lying on the white expanse of sand might symbolize the embryonic state
of their movement, but for most of the conference participants,
agrichar was still the best news they had ever heard.