Using algae to remove CO2

[teonanacatl]

Someone brought up the idea of using algae to remove CO2, there was a scientist who lived underwater for a while using this technique. Anyway I was thinking about this yesturday. We have a serious CO2 problem because what we have done is removed tonnes of relatively inert carbon from beneath the earths surface and turned it into CO2. So you say, why not just plant some more trees they will turn it into O2, well they also put the C into sugars which is fine whilst they are alive but when they die these sugars will become CO2 again. So using algae wouldnt work, because we would soak up all the CO2 onto the algae (alot of it) then what? Throw the algae onto the ground and let it decompose? Then all the sugars become CO2 again.

The only way one could hope to fix it would be to plant lots of trees that range in age so that they stored it, when one dies the others around it absorb the CO2 and keep planting, make them a carbon sink. Only problem with that is trees need water otherwise they output more CO2 then O2 and we are in a drought (well most of the country is).

[foolsbreath]

carbon sinks are a short term solution, but probably the best one we have at the immediate time

To answer the question of what becomes of the stored carbon, one must determine a time frame and end use of the wood.

If one makes a covenant stating that the trees can not be chopped down for 100 years, you have effectively stored that carbon for that time. How ever a better solution is using tree plantations for carbon sequestration as agro forestry, the timber is milled and used in products. The timber has then been utilized in a secondary carbon sink such as housing and furniture. this will have a further lifespan of up to and over a hundred years, at the end of which it can be recycled into a tertiary carbon sink

The bonus of agro forestry is that the trees will be harvested at the top of its optimal growth curve, and the area replanted meaning that more carbon will be sequestered compared to a stand that is not being cleared and replanted every 20-30 years

With agro forestry there will also be a higher survival rate than those plantings used for windbreaks etc or just for grants/tax breaks due to the intrinsic value of the timber

To be successful these plantings must be maintained. If one were to set up a carbon sink and wanted it to be recognised as one, there will be requirements that the sinks must be looked after and if lost through fire/disease etc replanted and any subsidies withheld till the planting reaches an equivalent level as before

There is already a national carbon accounting system to help people properly account for carbon stored in carbon sinks and the different end uses which encompass agro-forestry, farm forestry (wind breaks etc) and biodiversity outcomes (plantings for erosion/salinity control, reveg, aveg, wildlife corridors etc)

Certainly not all of Australia is suitable for carbon sinks, but there are lots of different species that respond well to different environmental conditions. For example, the New England tablelands will receive these plantings in the near future and using the right species of eucalypt will result in effective carbon sequestration, where the average family will have to pay for/plant 30 trees per year to offset their carbon emissions at a cost of 5-10$ per tree

[phloom]

I ahve the solution, we'll all become foresters and cabinet makers....and fill the land with trees and furniture!

seriously though does cut wood store carbon effieciently? the carbon produced in making fertilisers that are put onto plantation lands must surely offset any benefits?

otherwise you'd think, just plant fast growing species and put all the wood in a big cool shed somewhere for say a few thousand years or something.

Edited April 26, 2007 by phloom

[occidentalis]

So using algae wouldnt work, because we would soak up all the CO2 onto the algae (alot of it) then what? Throw the algae onto the ground and let it decompose? Then all the sugars become CO2 again.

But if the chemical energy stored in the algae can be recovered and utilised instead of fossil fuels, we can reduce our dependence on them. This is being worked on in New Zealand.

[Rev]

coral reefs are the best scrubbers

CO2 to CO3 in a basic aqueous solution is the best long term sink

too bad we are killing them too

there are encrusting algae that form limestone skeletons, these are seriously underexploited

[foolsbreath]

I ahve the solution, we'll all become foresters and cabinet makers....and fill the land with trees and furniture!

seriously though does cut wood store carbon effieciently? the carbon produced in making fertilisers that are put onto plantation lands must surely offset any benefits?

otherwise you'd think, just plant fast growing species and put all the wood in a big cool shed somewhere for say a few thousand years or something.

well yeah, thats it, isn't it, you can only revegetate or avegetate so much land but there is plenty of demand for wood products and if stopping illegal deforestation in places lake Indo and Peru etc is possible, the price of timber will indicate its true value making agro forestry a much more desirable field for land holders to move into.

As long as cut wood is not allowed to decompose, it is storing its carbon indefinitely and tree plantations are not fertilised at all, infact there is no carbon required to set up a forestry block unless direct seeding is used with machinery, producing a small initial loss of carbon and of course the harvesting procedures. In fact, by changing land use from pasture or cropping to forestry, you will be significantly reducing carbon loss through soils and stopping carbon and nitrogen being lost through fertilization.

Dangers in Australia are of course mainly fire and disease, but if any planting is to be accredited, these factors are calculated into the final equation eg any planting must realize a loss of say 20% (not true figures) to cover losses seen through natural causes.

there are also limitations set by the Kyoto protocol for carbon sinks to be recognized internationally, ie, areas planted must be into revegetation, and areas not cleared before 1990 within a localized area to which the offsets are to be returned etc etc to ensure that there is a biodiversity out come as well as sequestration. If such criteria are not met, one may not be able to trade carbon stocks if that was the aim of the plantation

[XipeTotec]

, there was a scientist who lived underwater for a while using this technique.

wow!!! was he a kevin costner?

Edited April 26, 2007 by shroomytoonos

[teonanacatl]

I dont think fixing it with algae and turning it into ethanol is the solution just yet, same goes for renewable fuel sources like biodes. We have to not only stop the increase in CO2 but it would be nice to decrease it, switching to biofuels would stop increase or slow it alot. I think the best idea is to get it into CaCO3 like rev said. All we need is a few thousand tonnes of CaOH......