En intressant egenskap av sockerrör är att det ina bara binder kol för kortare tid som allt som växer utan att platorna formar hårda kolhaltiga stenceller (fytoliter) som inte bryts ner utan binder kol fossilt i marken. Sockerrör och bambu är de växer som är väldigt bra på detta se t ex
http://www.abc.net.au/news/stories/2008 ... 352913.htmCitat:
"Plant stone is just like a glass jar that has the carbon inside it and that gets deposited into the soil when the plant dies and, basically, it's very stable, it's there for thousands of years," said Jeffrey Parr, also of Southern Cross University.
"The carbon is actually enclosed by a silica coating. The silica coating protects it from being decomposed in soils."
He says the phytoliths from sugar cane are even plumper, and hold even more carbon.
Some plants make more plant stones than others and with the warming world now desperate to capture and store carbon, these scientists believe they've hit on something big.
"What we've found is that all this organic matter is accumulated within seven years, which means that the organic carbon's been accumulating at a gold medal rate - one tonne, per hectare, per year," Dr Parr said.
Citat:
Mr Quirk grows sugar cane. While not as fast as bamboo, it's still locking carbon into plant substance at a rapid rate.
"With sugar, for every tonne of carbon we put into the atmosphere, we take 2.6 out," he said.
Professor Sullivan is the key is choosing the right type of sugar cane.
"One of the cultivars he's growing is actually securely sequestrating in the soil half a tonne more carbon dioxide per year than another cultivar of the sugar cane, so what that means is if that that farmer went and grew all of that cultivar, that high carbon sequestrating cultivar, that he would be - for every hectare he's got, he'd be putting another half a tonne into the ground for the next 5,000 years," he said.
Citat:
"This is a bit of a stretch, but if all the arable land on the globe was growing vegetation that had the same plant stone carbon sequestration rates as our best sugar cane, that would actually sequester nearly three billion tonnes of CO2 annually in the globe, which is about 20 per cent of our current rate of atmospheric CO2 increase," Professor Sullivan said.
Den vetenskapliga rapporten finns här
http://www.springerlink.com/content/35r ... lltext.pdf/Aryan
Helt klart låter detta intressant. Av de 30+ Gigaton CO2 som släpps ut från förbränning av fossila bränslen per år hamnar ca. hälften (15 GT)
i atmosfären som ökning; den andra hälften tas f.n. upp av haven. Vad han säger är att om alla grödor på all tillgänglig odlingsmark hade samma egenskaper som den bästa arten av sockerrör han studerat skulle 3 GT kunna tas upp.
Det är bra, men ett mycket enklare sätt att bli av med CO2 är att hälla ut lite järnsalter i haven så att algerna växer snabbare. Döda alger sjunker sedan till botten och blir till olja etc. med tiden. Eller kan utnyttjas för etanolproduktion (eller biogas fast det är sämre ur klimatsynpunkt).
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