Ever since I heard of it the first time the black earth phenomenon in the Amazon has always fascinated me, according to the wikipedia article terra preta will give a 38-45% higher yield of rice without fertilization when compared to fertilized ferralsol and the Biochar Fund gives an even higher figure of 840% (the figure is given in an unclear manner, it’s likely it refers to total biomass of the plants, not yield). Wherever the truth may be it’s obvious that this is powerful stuff that can simultaneously increase the crop yields in tropical countries while at the same time eliminating the need for expensive artificial fertilizers.

This is all well and fine but it’s the side effects that might be the most important thing. Since the whole process basically is about converting plant matter into non degradable biochar it will result in a reduction of atmospheric CO2. According to Nature:

That means turning unimproved soil into terra preta can store away more carbon than growing a tropical forest from scratch on the same piece of land, before you even start to make use of its enhanced fertility. Johannes Lehmann of Cornell University in Ithaca, New York, has studied with Glaser and worked with Sombroek. He estimates that by the end of this century terra preta schemes, in combination with biofuel programmes, could store up to 9.5 billion tonnes of carbon a year — more than is emitted by all today’s fossil-fuel use.

That would basically mean a complete reversal of global warming if it is the CO2 that is the culprit. Needless to say, the worst possible scenario will not come to pass either. So what would it take in practice to achieve for instance sequestering one billion tons of CO2 per year to win the Virgin Earth Challenge? According to Desmond Radlein of Dynamotive Energy Systems in a SciAm article it’s far from impossible.

I developed this rough back-of-the-envelope calculation of what it would require if one were to [attempt the Virgin Earth Challenge] with the agrichar concept,” Radlein explains. “One would need about 7,000 plants each processing 500 tons of biomass per day, which is a large number, but it’s not outside the bounds of possibility.” Such facilities would produce four parts bio-oil to one part carbon sequestered, so it would rake in money as well as carbon.

But apparently it’s not as easy as it seems to achieve the really, really good stuff.

In addition, scientists are finding it hard to replicate the original terra preta soils. “The secret of the terra preta is not only applying charcoal and chicken manure—there must be something else,” says Bruno Glaser, a soil scientist at Bayreuth University in Germany. Field trials in Amazonia using charcoal with compost or chicken manure find that crop yields decline after the third or fourth harvest. “If you use terra preta you have sustaining yields more or less constantly year after year,” he says.

“I’m skeptical about adding just a pure carbon source,” says Stanley Buol, a professor emeritus from the Department of Soil Science at North Carolina State University’s College of Agriculture and Life Sciences who spent 35 years studying Amazonian soils. “It will be black and look good,” but will it contain enough inorganic ions, such as phosphorus and nitrogen, essential to plant growth?”

Luckily just about anyone can easily experiment with this stuff, I will start myself this weekend. The plan is to try various amounts of charcoal mixed with ferralsol in order to hit upon the right mix, according to wikipedia the amount of C in current soils is as high as 9% so that will be a starting point.

However the coal needs to be prepared, I plan on soaking it in urine for a month or two first. Adding other organic material is also probably a good idea. Finally different levels of continuous additions of P and N to the mix has to be tested. I won’t use pots because organisms need to be able to freely move into the mix from the surrounding earth. Did I forget something?

During the past few years you would’ve had to be locked up in a basement by some lunatic to avoid having heard of global warming. I know it’s off topic to discuss it here but just this once, the reason for this is that today I “discovered” something that is far beyond crazy. I’ve never heard of this phenomenon on a global scale before and the scary thing is that it can be connected with warm periods, both empirically and theoretically.

Global warming scenario
At this point a lot of smart people believe that it doesn’t matter what we do, due to a force feedback loop we’re gonna get a lot warmer. So what, you might think? First of all no one really knows how a warmer world will affect the area of arable land and worst case scenario is that the whole landmass will be turned in to some kind of gigantic desert. Not really a problem, we can build a lot of nuclear power plants and start a massive desalination operation to get food, better yet if we manage to get the solar cells to be good enough to do the same. Heck, if we somehow manage to get fusion power up and running we could probably manage anything.

Sure the coming chaos will probably kill off more than half of us before we manage to make the above scenario happen. I’m kinda cynical though, the way we behave in this age of stupid makes me feel that the fewer of us the better, that’s why I don’t really give a shit as long as some of us survive, hopefully wiser and better equipped to take care of the planet, don’t count on it though…

Ocean anoxia
It seems however that the problem is not the heat, it’s an obscure (at least to me it was) side effect called Ocean anoxia (emphasis on ocean). If the water temperature close to the poles rise above about 5 degrees the water that the ocean currents bring there won’t easily sink to feed the loop, the most famous example of this kind of loop is probably the Gulf Stream. If you think that the surface temperature at those latitudes never will reach 5C, think again, they’ve been over 10 sometimes!

So when the oxygen rich surface water fails to sink we get a massive layering of productive surface waters and a dead oxygen depleted deep sea, these waters do not mix easily, trust me! As a Swede this is nothing new for me, this is a common problem in eutrophic lakes and more importantly, the Baltic Sea which we and the other countries around it have managed to kill with irresponsible agriculture, yay! What’s news (for me) though is that it can happen on a global scale, think Pacific instead of Baltic.

I know what you’re thinking, whatever… The deep sea is not important to the biosphere, it’s practically a dead zone anyway. Apparently the problem arises due to anaerobic bacteria which “burns” sulfur instead of oxygen, these things will experience a veritable Eldorado because oxygen is highly toxic to them, no oxygen == party time! This has happened before, it was probably the cause of the worst extinction event in Earth’s history!

Hydrogen sulfide
Naturally the byproduct of their metabolism is H2S instead of H2O, which is the case with aerobic bacteria and animals. It won’t take long before the H2S will start entering the atmosphere causing, yep you guessed it, major acidification which will make the above agriculture by desalination scenario a lot more difficult, enter Venus on Earth. The H2S will probably break down the ozone layer too.

On top of everything else we now need to create our own biosphere to block the acid and the UV radiation from killing us and everything we try to grow. That is going to be very expensive and require a lot of energy to setup, I wonder how many we will be able to fit in our brand new Biosphere, it has to be somewhat bigger than the one they have there in Arizona… And this time there won’t be any second chances.

The salvation, maybe
I have nothing reasonable to back it up with but I have the feeling that the only thing that will even give us a fighting chance to survive Venus 2.0 for about 500 000 years is fusion power, which will - if we can get it running - put more power at our hands than ever before.

So do whatever you can to speed ITER and DEMO on their way. The schedules for these two facilities feel somewhat unhurried… Our grandchildren will probably appreciate some kind of increased effort here.

If it really is us doing this by burning fossil fuels the irony is complete. It’s during these anoxic periods that the majority of the oil deposits were created because all the dead creatures falling to the bottom won’t be broken down properly in the oxygen depleted environment, they become oil instead. And so we are killed by the very event that created the thing we are using to create it.

Updates:
I just donated $10 to the EMC2 project on emc2fusion.org. It might be a long shot but the loss of $10 is not hurting me either.