It’s obvious that burning trees for heat or to create electricity is better from a greenhouse-gas point of view than burning coal and oil, because the trees can regrow and pull back the the carbon they released into the air. Or maybe it’s not so obvious, reports UnDark, a new magazine from MIT:
The report takes issue with two major assumptions on biomass: 1) That burning wood for electricity production reduces planet warming emissions compared to coal, and 2) So long as new trees are planted to replace the biomass that’s being burned, net emissions from biomass power are basically zero. But those claims are too simplistic, some scientists say.
The problem is that it takes years for regrowing trees to absorb any sizeable proportion of the carbon released quickly when they burn. Studies say that if the biomass isn’t collected well – if biomass companies rampage through established forests for their product – the carbon cost is very high for many years, if not longer. If we mow down all our forests to create electricity, it might even be worse for the atmosphere than drilling more oil and leaving the forests alone.
The problem isn’t really that biomass energy is worse for greenhouse gas emissions than fossil fuel-powered energy, it’s that badly-done biomass energy can be worse. Corporate transparency is important.