[leoedin]

Climate change is being driven by people extracting carbon from deep underground and releasing it into the atmosphere.

By that measure, burning biomass is CO2 neutral. The carbon released is not carbon which was extracted from the ground. It's carbon which was extracted from the air by plants.

All plant matter releases carbon dioxide as it breaks down anyway. Those trees which we burn as biomass weren't going to magically disappear - unless someone buried them they would eventually rot, releasing most of the carbon they extracted as they grew.

[belorn]

There are several concerns that gets left unanswered when people describe biomass as CO2 neutral. First is that modern growing of crops involve fertilizers, pumped fresh water, tractors/machineery, and transportation (biomass can not be compressed for easier shipping). The second issue is that in order to grow crops you need to clear out existing biomass in order to replace it with the crop used for biomass. Third people like to first talk about using it for carbon capture and green compensation for coal, oil and gas, only to later burn the same biomass under a CO2 neutral label.

Combined it make for a rather risky strategy for stopping climate change.

[leoedin]

Those are all good points. Unfortunately there's a huge amount of noise in the green technology space, which has the tendency to drown out the scientific thinking.

However, I don't think dismissing biomass (or biofuels) completely is necessarily the right approach either. It's essentially a method of using natural processes to capture energy from the sun, and has the huge benefit of producing energy which can be stored indefinitely. Storing enough energy to get through renewable lulls without resorting to fossil fuels is an unsolved problem, and biofuels may be one of our best bets right now.

It would be interesting to see a full cycle efficiency analysis of biofuels - what percentage of the energy gained is used to grow and harvest plants, how much agricultural waste is currently burned/rotting without energy extraction.

Our strategy for stopping climate change right now seems to be "do almost nothing", which also seems rather risky to me. The quickest way to deal with it would be to use the market to drive innovation by applying a high tax on all extracted carbon. If renewable or carbon neutral energy was significantly cheaper than fossil fuels, the rewards for innovation would be much higher and so we'd see all sorts of interesting solutions. Right now green technology funding mostly exists in a subsidy driven top down command economy.

Unfortunately that requires political will, something that's almost entirely absent right now. People are all for green initiatives right until it actually effects how much they pay for fuel.