The greenhouse gas problem is far more intractable than most people think, and although there is a solution in sight, we will need a technological revolution to implement it.
The solution Drexler envisions becoming possible in the not-too-distant future is as follows:
The way to remove CO2 quickly is to pump it, but this is a project too large to undertake with today’s manufacturing infrastructure. However, as I note in the Edge essay,
If we were good at making things, we could make efficient devices able to collect, compress, and store carbon dioxide from the atmosphere, and we could make solar arrays large enough to generate enough power to do this on a scale that matters. A solar array area, that if aggregated, would fit in a corner of Texas, could generate 3 terawatts. In the course of 10 years, 3 terawatts would provide enough energy remove all the excess carbon the human race has added to the atmosphere since the Industrial Revolution began. So far as carbon emissions are concerned, this would fix the problem.
A few specifics:* Nanosystems provides a physical analysis of a class of selective, thermodynamically efficient molecular pumps. Devices like these provide one option for satisfying the first condition I mentioned.
* Excess atmospheric CO2 is expected to be about 1 trillion tons in the time frame of interest, and the amount of energy required to collect and compress this to liquid density is about 1021 Joules.
* This is equivalent to 3 terawatts of electric power for 10 years, comparable to the total world electric generating capacity today.
* Solar arrays with an aggregate area equivalent to a 250-km square would provide ample power (assuming cells of mediocre photovoltaic efficiency, but placed in sunny locations).
* Advanced molecular manufacturing capabilities will make it practical to produce the necessary hardware to solve the greenhouse gas problem by removing the excess greenhouse gases, reversing net emissions.
Regarding molecular manufacturing, as I note in the Edge essay:The U.S. National Academies has issued a report on molecular manufacturing, and it calls for funding experimental research. A roadmap prepared by Battelle with several U.S. National Laboratories has studied paths forward, and suggests research directions. This knowledge will spread, and will change the game.
(I also high recommend reading Drexler's post on the problem of CO2 emissions leading to ocean acidification.)
The take-away from this should be that research and development spending in the area of molecular manufacturing looks like a promising course of action to solve the problem of rapidly growing atmospheric CO2 levels (which, according to the best available climate models, will have devastating effects).
Drexler's proposal, if it is indeed workable, is the only one I'm aware of that provides an alternative to planet-wide CO2 emissions regulation that quickly brings the total amount of the gas being released down to sustainable levels. So let's look into this further and attempt it if feasible. If we can pull CO2 out of the air with solar stations covering 250-km square of planet (less than 0.0000005 percent of its total surface area--I think, but I'd welcome corrections to any stupid mistakes I may have made in my math) at a rate sufficient to be able to control atmospheric CO2 levels, then the best climate change solution would be to build those solar stations as fast as we can. Of course would also want to emit as little carbon as possible in manufacturing and installing the stations, but it's important to note that it's okay to emit CO2 in the course of implementing this plan as long as the solar stations are able to function for long enough to yield a substantial net CO2 reduction over their life expectancy.
Reiterating what Drexler has to say about the relevance of molecular manufacturing (I highly recommend following this link to learn about this amazing concept) to this discussion:
The U.S. National Academies has issued a report on molecular manufacturing, and it calls for funding experimental research. A roadmap prepared by Battelle with several U.S. National Laboratories has studied paths forward, and suggests research directions. This knowledge will spread, and will change the game.
If we can accomplish what Drexler is calling for, we will be able to transform our unwanted carbon emissions into any carbon-based manufactured goods that we would care to make--hence heralding the dawn of the diamond age. Perhaps we will eventually learn that Drexler's idea is fatally flawed in some unforeseen way, but spending the money necessary to find out if it's realistic project still seems like a good investment given the immensity of the possible payoff.
And here's one more optimistic thought: Nanotech engineers tinkering with the new technology which will hopefully be available in the coming years and decades may well be the engine that will drive us out of our current recession/emerging depression. Remember that technology is a primary enabler of economic growth--and how quickly computer hobbyists in 1975 were able to launch themselves to billionaire status. Silicon Valley may yet be able to do for manufacturing what it already has for information processing, storage, and transfer. And that would change the world in ways we can scarcely imagine today.