I was going to comment exactly the same thing. We definitely CAN turn CO2 into fuel - but the energy cost would be staggering (especially considering that we use fuel, in the first place, FOR it's energy density). Plants would do that much more effectively (without mentioning that plants are clean, which may not be the case with fuel production from carbon oxides) AND that plants actually give us back the oxygen in such compounds. Though personally (DISCLAIMER: I'm not a materials, chemical or any kind of engineer/expert) I think the most energy-efficient way to deal with carbon-based greenhouse gases (or really, any carbon-based pollution) is to crack the molecules in order to turn carbon into graphite/graphene (at ~805kj/mol^-1 for CO2, ~1050kj/mol^-1 for CO and ~1200kj/mol^-1 for methane, it sounds relatively energy inexpensive - considering that CO2 and CO are calculated in PPM and methane in PPB, assuming you can cheaply capture them, you could clear a huge volume of atmosphere - then again, I don't know how much energy/money is involved in capturing these gasses...) Of course, something even more energy-efficient, cheap and effective to reduce carbon dioxide in the air (along with it's less-spoken-of brother, nitrogen oxides) is to actually reduce our consumption of fossil fuels. Do plants even filter out N2O?
Wow, this is great question. The answer is... sorta . Trees do remove particulates, lower air temps, retain moisture in soils, retard erosion an of course are a CO2 sink. And yes, the best way is to reduce emissions. But if we can reduce emissions, and reforest parts of the planet, hey why not?Of course, something even more energy-efficient, cheap and effective to reduce carbon dioxide in the air (along with it's less-spoken-of brother, nitrogen oxides) is to actually reduce our consumption of fossil fuels. Do plants even filter out N2O?
Indeed - any two effective solutions used together, when feasible, is always a better idea than only implementing a single one. The more we can do for our environment (at least without losing all of the advantages technology brings), the better. Though that answer is VERY interesting - I never realized that trees were such effective pollution-cleaning tools. I'm definitely signing up (if there is any in my town) for a tree-planting activity next spring. That "sorta" is a "yes" for me though - because even though they don't capture massive amounts of it, it does mean that plants, over time, can do that job - and that's good.