The Science of Biochar

The science of Biochar is just beginning. We've only just started thinking about restoring soils as a way to help both mitigate and adapt to climate change, but most people in the mainstream have hardly heard of Biochar.
Let alone understanding the implications and the potentially huge impact Biochar could have in helping our entire society become sustainable.

One of the primary reasons I put my career on hold and have been working full time trying to help start the Canadian Biochar Initiative was because I saw some potential with the technology, but it is only recently that I have begun to understand the magnitude of its potential for good.

I've been communicating a lot with people who have been talking about climate change recently. There are some who say that we don't have very much time before we need to start drawing down hard on atmospheric CO2.

It was Johannes Lehmann of Cornell University who first emphasized that Biochar "could remove billions of tonnes of carbon from the air each year".
That caught my attention, so I wanted to reproduce his calculations.

This is nothing to laugh at, because governments in Canada are now starting to spend increasing billions of our taxpayer dollars on schemes to reduce our "emissions intensity" with megaprojects like underground Carbon Capture and Sequestration (CCS) which would only reduce the projected carbon emissions from the Alberta Tar Sands by about 7.5% after about six years -- and would require an additional 20 to 50 years of substantial investment in infrastructure to have any significant impact at all.

It might also require that we use an additional 900,000 gigawatt-hours of energy -- per year! This is equivalent to hundreds of new nuclear plants or hundreds of thousands of Wind turbines. All this at a time when governments are running multi-billion dollar deficits.

We could end up spending trillions of taxpayer dollars undertaking a monumental task that ultimately ends up being fruitless -- especially if we find out 10 years from now that CO2 wasn’t the primary cause of climate change.

After all, we could let nature do the sequestering for us – by allowing nature to thrive – and then pulling the carbon out of the atmosphere as we pyrolyze the residuals in a process that also provides us with an energy surplus. This is the "magic" of Biochar!

At worst it would be environmentally benign and at best it could be tremendously beneficial with respect to food security, secondary environmental contamination issues like fertilizer runoff and leaching (which affects our oceans and other water bodies as well as our groundwater) and could possibly even help reverse desertification.

So even if Biochar could conservatively sequester 1 or 2 Gigatonnes of CO2 per year, that would still be 3 to 4 magnitudes of order greater than CCS.

And, interestingly enough, the Alberta Research Council has calculated that we might actually be able to utilize Biochar at a profit -- particularly for farmers!

Now, I live in Ontario, so I was only recently introduced to the Palliser Triangle in southern Saskatchewan and southeastern Alberta. I knew it was dry out west, but I learned that the Palliser Triangle actually covers more than 200,000 square kilometers of area and it's so dry that sand dunes actually cover more than 3,400 square kilometers of the region.

I completed a soil science course last year at the University of Guelph for the first time.
I've always been interested in Geography, so it was interesting to learned that only 5 percent (about 46 million hectares) of Canada's vast terrain is actually suitable for crop production and that 85 percent of this (about 39 million hectares) is in the Prairie Provinces.

I also learned that, in the long term, soil degradation is the most serious threat to the agriculture industry in Canada and that 5 percent of cultivated Prairie farmland is at high to severe inherent risk of water erosion, and that 20 percent of the cultivated land continues to be at risk of moderate to severe wind erosion.
Wow! Seems that our soils aren't robust and fertile as we once thought and we are degrading them at ever increasing rates.

What are the implications for future food security?

Now, getting back to the Palliser Triangle and Biochar.
200,000 square kilometers translates to 20 million hectares.

Now that I knew about the Palliser Triangle, I thought, "Well, if we could put 5 tonnes of Biochar on each hectare in this triangle this would translates to 100 million tonnes of carbon.
(Actually, if we assume that the permanently recalcitrant carbon in Biochar is only 80% then this is only 80 million tonnes.)

Since each tonne of carbon would be equivalent to 3.67 tonnes of CO2, this translates to 293.6 million tonnes of CO2.
Now, compare that to the "up to five million tonnes annually by 2015" for CCS.
That's more than Fifty Times (50X) the amount of carbon sequestered!

It also vastly exceeds the 67 million tonnes of CO2 equivalent emissions that the Tar Sands might reach by 2015. In fact, it's more than four times more!

So what's the economics of it?
I've estimated that for $200 million -- for research to prove that Biochar is either neutral or even beneficial to Canadian soils, we could sequester these 293.6 million tonnes of CO2.
That works out to a cost for the taxpayer of only $0.68 per tonne of CO2.

Of course this is simplifying the costs, but... maybe not, if we consider the increased yields for farmers and reduced soil erosion and potentially reduced need (and cost) for fertilizers, among many other benefits like protecting watersheds.
And this is where I started to think, maybe this has real possibility.

So I came back to the question of soil carbon.
I knew that in the past century as we've been plowing and essentially 'mining' our soils of nutrients that we have seen the organic carbon content in most fields go from about 5 percent down to about 3 percent.
I also remembered that the "Terra preta" soils -- those pre-Columbian soils that were created by humans in the Amazon Basin -- had, on average, about three times more soil carbon than in the surrounding poor soils.
I remembered from my soil course that some soils in Canada were very carbon deprived, and found out that the soils of the Palliser Triangle actually have some of the lowest soil carbon content in Canada -- somewhere around 1% soil carbon, which is quite low.

So, based on what I learned about soils in my Guelph University course I did a few simple calculations and I found out that adding 5 tonnes of Biochar per hectare would actually only increase the carbon content of the soils in the Palliser Triangle by about 0.2%, and if the average soil carbon content is only 1% right now and our target is to double it (to only 2%) it would take at least four applications of Biochar (at 5MG/ha) to get to 2% carbon content in the soil -- and this would be equivalent to 1.174 Gigatonnes of CO2 sequestration!
This very closely matched Johannes Lehmann's calculations. Dr. Lehmann had once said that the Earth's soils could remove between 5.5 and 9.5 billion tonnes of carbon from the air each year.

This amount of CO2 sequestration capability – on less than half of the total cropland in Canada – was already enough to offset all of the CO2 emissions from the Tar Sands for at least the next 17.5 years. It didn’t even account for the other 26 million hectares of land suitable for crop production in Canada that might also benefit from Biochar!
And it didn’t account for the fact that we might be able to bring our soil carbon content up to 3% or even 5% or more.

So, with Biochar, Canada could actually very quickly reach our Kyoto commitments -- and even go far beyond them.
What I realized was that Canada could even become a carbon negative country.

After all, according to official government statistics, Canada only produced 721 Megatonnes of greenhouse gas emissions in 2006 (carbon dioxide equivalent emissions).

So if we could sequester almost 300 Megatonnes of CO2 on just 20 million hectares of land, what if we were to add 10 tonnes of Biochar on each of the 46 million hectares of croplands in Canada?
I would think that we could draw down carbon pretty fast.

And, remember, my contact at the Alberta Research Council said that we could do it at a profit!