Good Afternoon Ladies and Gentlemen!
I’m a mechanical engineer with experience in the
nuclear industry. As one trained in the
burning of fossil fuels, I became interested in the climate change issue about twenty years ago.
That interest evolved into participation in Canada’s studies of means
to reduce greenhouse gas emissions
as taken on under the Kyoto Protocol. I
represented the Canadian Nuclear Association on several committees a decade ago.
We are still a long way from deciding how to cope
with climate change. It seems we have some doubts about the need
to reduce atmospheric carbon dioxide and
just how that might be done.
I’m here to seek your help with one more process
which could remove carbon dioxide from the
atmosphere and might simultaneously improve
the planets soil. It depends on tweaking the carbon cycle to enhance the soil carbon sink.
Is it possible we could turn our carbon emissions
into an asset toward a sustainable
have been considered to manage greenhouse gases. Most have to do with emissions reduction.
A few focus on removing carbon dioxide from the
atmosphere. My agricultural colleagues on
the Kyoto watch proposed doing that
with growing plants.
Some carbon absorbed by plants via photosynthesis
is deposited by natural processes in the
soil. Large quantities have been trapped over millennia.
No-till farming practices and composting are
cited as means of keeping more carbon in the soil.
This seems fraught with uncertainty though. How
much carbon containing plant material
simply decays quickly and returns as carbon dioxide to the atmosphere?
Will soil reach an equilibrium carbon content and then absorb no more? Likely some of you are involved in advancing
energy is essentially emissions free. My task with the greenhouse management committees was to promote the idea nuclear generated electricity just as a means of avoiding CO2 emissions.
I began to wonder if it could be used in a
way to go beyond that and actually help
absorb CO2 from the atmosphere. Indeed it
As an example, I considered a scheme to pump
water from northern Alberta to irrigate
southern growing regions and thus
enhance plant growth there. I found half
the water from the Slave river could grow enough carbon dioxide absorbing vegetation to
meet Canada’s Kyoto commitment. Conversion of the plant material to charcoal was identified as a
way ensure it stayed intact for
hundreds or thousands of years, thus becoming
an enduring carbon sink.
Crazy idea? Yes!
Remember though, that we are in a province where we are seriously planning to capture carbon dioxide from
smokestacks and pump it underground at
I was encouraged.
found and went to a relevant
conference, in Georgia. About 50 people
attended including archeologists, soil scientists, and experts in bioenergy.
I learned that archeologists had long known of an
ancient civilization in South America that
apparently incorporated charcoal in soil with a variation of slash and burn agriculture. Very rich soil known as
Terra Preta resulted. It is still there hundreds of years after the
civilization collapsed – possibly from
disease introduced by European explorers.
The researchers had gathered to discuss the
implications on carbon dioxide mangement as well as soil enrichment.
The sense of discovery at this little conference
was palpable. It seemed to me these people
were onto something useful.
I came home
enthused by the excitement to make more people aware of the possibilities.
This land portion of the carbon cycle indicates
plants cycle some 120 billion tonnes of
carbon through the atmosphere annually.
Growing plants absorb carbon dioxide from the atmosphere via photosynthesis into carbon bearing materials. Most is
returned to the atmosphere as carbon
dioxide through consumption by plants themselves and various animals from microbes to elephants -
and burning of plant materials.
Humans control about 24 billion tonnes of this
cycle by my estimate. Emissions from
fossil fuel are about 8 billion tonnes. This simple analysis suggests the potential is there to counter fossil fuel
emissions through conversion of plant
material to charcoal.
Could we modify agricultural techniques to ensure
a much larger portion of carbon is
retained in the soil?
More specifically, could we convert a portion of the plant
growth we manage to charcoal and place it
in the soil to serve as a carbon sink and a soil enhancer?
The conference in Georgia sparked a lot of
Later on, in 2007, an Internet discussion list
was established. Individuals involved
tirelessly spread information on the concept and try to coordinate experimental work on biochar production and soil
Now, the concept
has “gone viral”. Many enthusiasts are trying it out the concept in their backyards and farms.
Internet searches in 2004 came back essentially empty. Now a search on
“Terra Preta” or “Charcoal in Soil” yields
hundred of thousands - or more - “hits”.
There is so much information it’s difficult to separate dreams from
and engineers are involved. This
diagram from a 2009 article in Nature
Communications provides an overview.
It identifies potential sources of carbon from
agricultural wastes and forestry activities.
It shows that a combination of oils, fuel gases and char could be produced. The char portion would be added to soil sequestering the carbon there.
The anticipated improvement in soil fertility
feeds back into the process and further
enhances primary production of biomass.
The stage is set for an agricultural process which removes carbon dioxide from the atmosphere – and improves soil and
agricultural production. Not many global
warming solutions provide such a double benefit.
some problems though. Let’s consider some,
progressing from least to most
important issues, a la David Letterman.
How would the process be financed?
There is substantial evidence that charcoal can
last for hundreds to thousands of years.
Indeed, it often provides the material for carbon dating related to archeological
and other studies. Carbon dating is central to understanding the Terra Preta soils found in South America and
A credit scheme could be developed and factored
into cap and trade policies currently
studied as a means of carbon dioxide management.
abandoned charcoal kilns in Death Valley illustrate classical means of producing charcoal. Wood is burned with insufficient
oxygen for complete combustion. One can imagine the pollution that these would create on the scale needed to cope with global CO2 emissions.
are working on methods to produce char cleanly and efficiently. Most use energy from biomass itself to drive the
process and many propose to co-produce
fuel from excess flammable gas . This process from Danny Day and the Eprida Foundation in Georgia adds other
nutrients to the biochar based fertilizer
product as well.
mechanical engineer, I can
imagine there are many ways to conserve energy
and reduce pollution. As a mechanical engineer with nuclear experience, I contemplate that the needed energy might
even come from nuclear generated
electricity. The production of biochar and fuels could thus be increased to
conserve organic material and
provide more fuel for transportation and
That brings us to another issue. Now I’m really getting in over my head!
My experience with soil is limited to being raised on a farm in central
Alberta. I encountered various types of soil on the farm and wondered how they
came to be formed. How essential is organic matter to soil fertility? I
certainly need your help to understand this.
To quote Henry Janzen, of Agriculture and Agri – Food Canada here in
Lethbridge, “ Soil organic matter is far more than a potential tank for
impounding excess CO2; it is a relentless flow of carbon atoms, through a
myriad of streams – some fast, some slow – wending their way through the
ecosystem driving biotic processes along the way” through provision of energy
It is thought that charcoal acts to help bacteria and fungi drive the soil
building processes that Henry refers to. How far can we go in converting
organic matter to char before we starve the microorganisms which maintain soil
The number 1 question!
Can we really be confident that the addition of
charcoal to soil will help increase it’s
fertility. Studies of the Terra Preta soils over the years have provided substantial evidence that fertility is
improved – at least in the tropics. There
is evidence of human caused soil
improvement here in Canada too - going
back thousands of years to the last ice age.
Many hobbyists and researhers are now experimenting
with a lot of enthusiasm.
However, It seems to me it will take a long time
and a lot of controlled science based work
to evaluate the process in terms of
increased fertility and productivity over
the long term. Several decades of discovery seems warranted in view of the potential for climate change
we are facing – whether warming or cooling
is associated with it.
In summary, we may need to control climate
change, through greenhouse gas control or
other means, if human development is to
The carbon cycle provides insight as to one way
nature does it. Humans can help.
We’ve considered a revised agricultural
process today. It presents a promise
to turn carbon dioxide emissions into a long term agricultural asset. I’m hoping some of you will turn your attention to this
and undertake some evaluation. If the
promise pans out, the side benefit of soil improvement might even turn out to be a more important bridge to
sustainable agriculture than the initial
goal of carbon dioxide removal from the atmosphere.