Carbon Dioxide Removal (CDR)

I think this video does a pretty good job of trying to simplify a complex subject. By focusing on two of the many approaches to CDR, it introduces the issue in a memorable way. But the issues with trees in particular are greatly over-simplified here.

The thing is, if we are going to cease using fossil fuels, I think everyone already has this uneasy sense that will force a lot of lifestyle changes - what about all our STUFF?! Do we have to give up shopping?! There is a huge chemical industry that makes a lot of essential materials for modern life (and, sure, a lot of nonessential crap along with). Without oil or coal, can that industry still exist? Well, there used to be a somewhat primitive chemical industry based on trees! When I was a kid (half a century ago), hardware stores sold "turpentine" instead of mineral spirits for cleaning up paint. Turpentine was a chemical extracted from the residues of pinetrees - which were being grown mainly for paper-making and lumber. I think we will see a great shift in the chemical industry in the next couple of decades - to feedstock of biomass.

If we grow fast-growing plants, they take up a lot of carbon dioxide. Then we "pyrolyze" the biomass - heat without providing oxygen - and this converts the biomass into two things: charcoal residue called biochar, and pyrolysis gas. The pyrolysis gas contains steam along with a variety of basic organic chemicals which the existing chemical industry is very capable of reforming into just about anything you can imagine. So right now, we see people making biochar with combustion - burning part of the (say) wood to convert the rest to charcoal and the burning also gets rid of the nasty smoke. But it won't be long before people realize that smoke and gas is THE replacement for petroleum.

And the biochar - it is a great soil supplement and we already know that we need to restore farmlands to greater natural productivity. That need is only going to increase as we wean from fossil fuels and can no longer generate the copious amounts of ammonia that modern agriculture consumes for fertilizer. Biochar does not REPLACE ammonia, but it does make soil better able to hold the nutrients that are added so they remain available for plant growth (instead of leaching to groundwater and rivers and causing algae blooms in freshwater and coastal seas).