A discussion in Grist this morning, features leters to the editor in the NYT by opponents of Brazilian sugar cane ethanol.

They cite a couple of negatives of cane ethanol.  Might as well cite all the reasons that fuel farming is a bad idea.

They forgot starvation and food riots.  And diversion from real solutions, like the following.

There are other sources for biogas (than the municipal waste mentioned in the letter to the editor), that actually reduce GHG dramatically.  Manure, organic garbage, and farm biomass waste.

Since methane is 21 times worse a GHG than CO2, by converting these sources to biogas (before returning the resulting organic fertilizer byproduct to the soil), huge amounts of methane release are prevented.  The biogas can then be converted to electricity to backup a renewable power grid, it is easily stored for that purpose.

For every kwh worth of CO2 emitted (from using the biogas to generate power) 20 times that effective amount of GHG, in the form of methane is cancelled.  

Manure otherwise runs off into the ecosystem, combining with carbon stored as cellulose in dead plant matter in wetlands, for instance, to release methane.  One part of nitrogen (manure) to 30 parts carbon (in the cellulosic biomass in the wetlands) makes the perfect GHG generator.  Turning millenia of stored carbon into methane in the atmosphere.

If 5% of our energy came from biogas generated from these waste sources, 20 time that effective amount of GHG would be offset.  100% of our GHG emissions.  Methane as a backup for a renewable grid and as a backup fuel for plugin hybrid hypecar (ultralight, ultra-efficient) vehicles could replace fossil fuel use, oil, gas, and coal.  Climate disaster and dependence on foreign oil and soaring energy prices, all problems solved.  

Ethanol keeps gas guzzling going, diverting the political and financial capital to get this biogas backed up, renewable energy revolution going.