The idea employs biomimicry by deploying small-scale units of “trees” to soak up more CO2 than real trees, wherever you might need them. “You can remove CO2 anywhere you want, and it can deal with emissions from anywhere else on the planet,” said Allen Wright, a scientist at the Lenfest Center. “There’s no real major discovery or invention that has to happen that would prevent us from deploying that technology tomorrow.”
I was reminded of Nate Lewis' work at Caltech, where scientists are researching applications for artificial photosynthesis through DoE's Energy Innovation Hub program. This is to say nothing of cloud-seeding, stratospheric sulfur injections, space-based mirrors, or other tricks we might deploy in the future to regulate our climatic effects.
Basically, humans are testing out a diverse array of technologies that will allow us to tap into energetic fluxes with more precision and control than ever before. Instead of (more likely, in addition to) mitigating fossil fuel combustion, we could literally suck the carbon from the atmosphere. Instead of relying on autotrophic photosynthesis to convert solar energy into useful organic matter, we could produce technologies that do so much more efficiently.
In short, the sun is the answer to all our problems. Popular solutions like solar panels, scaled biomass and wind turbines already tap into and tinker around with solar fluxes. Long-sighted research like artificial photosynthesis and plastic trees aim to do the same thing.
Modern-day Malthusians like to play the apocalypse card, noting that the Earth is finite and that economic growth on a bounded planet cannot continue infinitely. They're right. But they're also assuming humans can't expand the boundaries. Humans currently use on the order of 15 TW of power, which is a lot, until you consider the 6000 TW of solar power that hit the Earth's surface (on average). Most of this is refracted back into outer space, with some IR radiation trapped in the atmosphere by greenhouse gases. If we generate all human power with solar energy, we'd go a long way towards increasing resource security and access. If we could increase solar energy generation by just one order of magnitude, we'd really have energy that's too cheap to meter.
Technology has for centuries extended humankind's prosperity and wealth (good examples being the internal combustion engine, artificial nitrogen fixation, telecom and biotech, and the Green Revolution). Malthusians are right in that we live on a planet with bounded natural resources, but they assume that the machines that convert our most abundant fuel source are the most efficient (i.e., that plants are the best way to convert solar energy into useful energy).
We have nowhere near the technological efficiencies, capabilities, or scale to achieve this right now. But as a thought experiment, it's possible from an engineering perspective to imagine a future in which we expand planetary boundaries by improving on nature's energy conversion mechanisms.
UPDATE: My colleague Jeff Kessler forwarded me two pretty awesome articles from UCSD that break down the math on, respectively, energy use growth and economic growth (the first being a historically decent proxy for the second). Those posts are available here and here.
If I may be so bold as to summarize them in a sentence: there are thermodynamic and resource limits to infinite growth in economies and energy use; maintaining pace for 200+ years will result in over-consumption and ecological catastrophe. I don't disagree that the Earth (more appropriately, the solar system) is a bounded system. However, I believe a combination of decoupling, population stabilization, energy generation portfolio diversification and solar concentration, and perhaps inter-planetary colonization (we're talking about centuries from now, remember) can combine to avert ecological over-drafting. In the mean time, we should not worry about these thermodynamic limits and aim for "steady-state" economic coasting, certainly not when we are nowhere near those limits at present and half the world's population lives on less than $2/day. Perhaps when we approach the thermodynamic limits discussed in the UCSD articles, we can begin to discuss the design of a steady state economy. But in the midst of economic crisis and widespread poverty, now is not the time.
Economic growth and technological innovation remain the answers to Malthusianism, if employed timely and appropriately.
