Well, for those of you geoengineering hacks who are keen on biochar, this week provided no lack of entertainment!   Quite an uproar took place in UK based newspaper the Guardian.  George Monbiot took aim at biochar and its promise to sequester carbon dioxide in the atmosphere.  No holds barred either:

"Sorry, not charcoal. We don't call it that any more. Now we say biochar. The idea is that wood and crop wastes are cooked to release the volatile components (which can be used as fuel), then the residue - the charcoal - is buried in the soil. According to the magical thinkers who promote it, the new miracle stops climate breakdown, replaces gas and petroleum, improves the fertility of the soil, reduces deforestation, cuts labour, creates employment, prevents respiratory disease and ensures that when you drop your toast it always lands butter side up. (I invented the last one, but give them time)."

Toast landing butter side up?  If only!  He went on to pick, poke, and prod biochar for a few more paragraphs, and implicated a few heavyweight proponents...

"This miracle solution has suckered people who ought to know better, including James Lovelock, Jim Hansen, the author Chris Goodall and the climate campaigner Tim Flannery. At the UN climate talks beginning in Bonn on Sunday, several governments will demand that biochar is made eligible for carbon credits, providing the financial stimulus required to turn this into a global industry. Their proposal boils down to this: we must destroy the biosphere in order to save it."

...before concluding:

"None of this is to suggest that the idea has no virtues, simply that they are outweighed by hazards, which the promoters have overlooked or obscured. Nor does this mean that charcoal can't be made on a small scale, from material that would otherwise go to waste. But the idea that biochar is a universal solution that can be safely deployed on a vast scale is as misguided as Mao Zedong's Great Leap Backwards. We clutch at straws (and other biomass) in our desperation to believe there is an easy way out."

Admittedly, our mate George has been a bit dark lately.  Okay fine, I'll say it: downright doomsdayer.  At least from where this editor sits, the whole biochar piece, while it had its finer points about biochar not being a silver bullet for climate change, was a teensy bit scathing.  How did the heavyweights respond?

James Hansen felt he was taken a bit out of context...

"It is unfortunate that George Monbiot has insinuated that one of us (Jim Hansen) is a believer in biochar as a "miracle" solution for the climate crisis. If he is basing this on our published papers, then he has grossly misunderstood them. An attentive reader would know his insinuation is false by simply examining our land use-related assumptions in our recently published peer-reviewed paper, Target atmospheric CO2: Where should humanity aim?

Broadly speaking, our climate change mitigation scenarios are strictly illustrative in nature, in other words, they serve to convey the types, magnitude and time frame of mitigation measures needed to reduce atmospheric carbon dioxide amounts."

James Lovelock clarified his position...

"I usually agree with George Monbiot and love the way he says it but this time – with his assertion that the latest miracle mass fuel cure, biochar, does not stand up – he has got it only half right.

Yes, it is silly to rename charcoal as biochar and yes, it would be wrong to plant anything specifically to make charcoal. So I agree, George, it would be wrong to have plantations in the tropics just to make charcoal.

I said in my recent book that perhaps the only tool we had to bring carbon dioxide back to pre-industrial levels was to let the biosphere pump it from the air for us. It currently removes 550bn tons a year, about 18 times more than we emit, but 99.9% of the carbon captured this way goes back to the air as CO2 when things are eaten."

... and Chris Goodall brought us back into focus:

"If instead of letting plant matter rot, it is turned into charcoal which is almost pure carbon and stable for many centuries, we are reducing atmospheric concentrations of CO2.

No one disputes the basic science, even George. If we can get this to work on a large scale, we can make a significant difference to greenhouse gas levels. We will have to take the organic outputs of large areas of land in order to achieve this and Monbiot is right to express horrified disbelief at some of the figures that we have suggested.

Here we depart from the path of agreement. Monbiot mentions but then ignores the other benefits of biochar. These are at least as important as direct climate change mitigation. First, soil dosed with charcoal can substantially improve agricultural productivity. Food crops grow better.
...

The second effect of biochar is to reduce the emission of other greenhouse gases, such as nitrous oxide and methane, from the soil. Thirdly, conventional fertilisers added to biochar appear to be much more effective and less likely to be washed away. Biochar-dosed soil therefore maintains its fertility better.

No one argues that biochar's effects are well understood. Scientific investigation is only just beginning. Next month sees the publication of Biochar for Environmental Management, a book edited by Johannes Lehmann and Stephen Joseph, two of the world's pre-eminent scientific advocates of biochar. This 400-page book is not the work of gullible fools, it is a resolutely serious attempt to tell the world of the many uncertainties surrounding how best to make and apply biochar.

...
Yes, we don't yet understand fully why biochar works but this is not an argument to ignore it or rule it out. I challenge George to read the science in this book and then tell us whether he is quite so skeptical as he is today."

Thankfully, amidst all the kerfluffle, our dear boy Marc Roberts stood by, and calmed matters with a punchline:

Perhaps we should keep the jury out on biochar/charcoal a bit longer and review the science as it becomes available.  Like any other technology or strategy to fight climate change, let's not try to automatically assume it is a solution to solve all problems, let's keep the debate healthy and well-informed -- and on the same note-- not resort to cynical criticism of people for keeping a flow of innovative ideas coming through.  In this day and age, we need all the bright ideas we've got, even if only some of them shake out in the end.   

Related Reading:
Can Burying Charcoal Cool Down the Planet?
Ignore Soil at Your Peril