Crops would suck up Co2!
None more so than oil rich algae, that suck up 2.5 times their body-weight in Co2 and furthermore, double that body weight and absorption capacity/oil content, every 24 hours!
Some algae are up to 60% oil!
And as an alternative high yield crop, only require 1-2% of the water of traditional irrigation.
Now none of this is dependent on whether or not we have climate change, but rather, the rising price of oil!
Peak oil, and the relationship with energy, and sustainable, enduring economic growth!
And the obvious energy alternative for us, is cheaper than coal, carbon free, thorium power!
Which by the way, pumps out power, when the sun doesn't shine or the wind doesn't blow! And we Aussies have enough of it, to power the world for up to 700 years?
After that, what's is wrong with turning our biological waste into cheaper than thorium power, particularly, if coupled to more Aussie innovation; the super silent ceramic cell, which by the way, also provides endless free hot water, even when the sun is not shining!
And coal can still be accessed for CSG, which can be used as CNG, powering quickly refuelable electric vehicles, that depend on ceramic fuel cells, with the highest energy coefficient in the world, at around 80%; and where the exhaust product is mostly water!
And none of these things ought to be done in response to real or imagined climate change, but because they are the most pragmatic available solutions to growing a very healthy growing economy!
We need no other reason beyond that, but particularly, given we stare in the face of a new economic downturn, that given huge unprecedented global debt levels, could be worse than the Great Depression!?
Rhrosty.

Footnote:
B of B is completely correct, with regard to coal, as a excellent alternative to oil for many of the things we now use carbon rich oil for.
We also have an option of mining the reef, for its much lower carbon production paradigm, in common use, oil!
And I've read some expert industry commentary, that proposes, we may have larger hydrocarbon resource to our immediate north than the entire M.E.
Why, just tapping into an exporting the contents of the Townsville trough could payoff the state debt, ten times over, and there's bigger vastly more promising prospects, just a little further out.
We would however, need to reinstate our gas and oil corporation, lest some airhead, accuse us of nationalizing our oil industry!
We could still do that, if we wanted to build a huge income earning sovereign fund, and then only by utilizing the share market!
But particularly, if we just over supplied the oil market, [and I believe we could, given the probable size of the resource,] thereby driving down share prices.
Even if we didn't take that course, we could earn the national purse around a trillion per!
And we do need real money to actually develop endlessly sustainable real alternatives, if only to have an assured ultra reliable supply, after we traverse through peak oil, and its unaffordable energy and almost inevitable quite massive economic downturn consequences?
Rhrosty.

Further footnote:
Oil rich algae production doesn't need arable land, but can be grown almost anywhere, hydroponically, utilizing only problematic effluent! And or sea water!
One industry spokesperson currently employed in algae sourced bio diesel production in our own northwest, is on the public record stating, given necessary scales of economy, these bio diesel or alternative jet fuel products, could, even with a fuel excise applied, be retailed for just 44 cents a litre!
Typically the yanks just crack on producing something, while we invent all the ultra absurd reasons, we can't; or should that read, just won't!
Rhrosty.

Hi Cohenite,
Thank you for the two references you included: you have added to my education. Using Wikipedia only because it is fast, I did look up Betz' Law and the Shockley–Queisser limit. Betz' Law gives us, if I read it right, a maximum of 59.3% efficiency in an unshrouded wind-electric device and an unstated greater maximum if the air flow is shrouded.
The Shockley–Queisser limit puts the maximum efficiency of a single p-n junction solar cell as no higher than 33.7% rising to 86% for a cell with mutiple layers.
How am I going?
Photosynthesis has an efficiency 3 to 4 orders of magnitude lower than these figures but is still able to function effectively at keeping our atmosphere almost stable. It is indeed a pity that the ability that plants have to take carbon out of the atmosphere has a significantly lower rate than humans' of adding carbon dioxide to the atmosphere: hence the CO2 concentration keeps increasing as does the Greenhouse Effect of that increased concentration.
One of the differences between us is that I can see alternative or renewanle energy sources improving over time, while many on this thread see them as relatively inefficient, at the moment and presumably unchanging into the future.

I go back to my original statements:
1. renewable or alternative energy sources (ie not coal, gas or oil) can only improve in size and efficiency up to the high limits that Cohenite alludes to, and
2. that coal (& oil & gas) are too valuable to burn just to make energy available for everyday processes.

To which pair I add a third point and that is that if we wish to have safe and continuing sources of energy for the future, research into renewable or alternative energy seems to be the field which will offer the greatest growth.

I am being polite and reasonable: I ask everyone contributing to this thread to do likewise. We may not convinve every reader but we have made a polite attempt to show that alternatives do exist in this debate.

Brian, are you aware that there is also major upside potential in nuclear energy technology rollout, such as the Integral Fast Reactor and much cheaper designs? (http://thebreakthrough.org/index.php/programs/energy-and-climate/cheap-nuclear) What is your basis for saying 'renewable or alternative energy seems to be the field which will offer the greatest growth' (remembering that the climate needs these techs to rolled out at massive scale NOW).

What do you make of France being able to largely decarbonise its electricity with nuclear in only a little over two decades, while Germany, going hell for leather for renewables exclusive of nuclear is actually going backwards (emissions rising), and similarly Denmark not doing much better?

You are just so polite Brian.
But you seem to have ignored my very polite request. So I will repeat.

Where Brian is the proof for AGW? You know what has happened with the economy under the carbon tax and RT, so why waste more money trying to develop technologies which are massively more expensive than our sources of abundant fossil fuels?

Can you supply proof these renewables are to be less expensive and help us return to the comparative advantage we once had in the cost of energy?

It is impolite and unreasonable to ignore people when they address you, Brian.