Land availability for biofuels
The amount of biomass required to replace a significant proportion of the fossil fuel used in transport runs into millions of tonnes. Hence, a crucial question is that of biomass yield. Higher yields obviously enable a similar amount of biofuel to be replaced using less land. However, land use efficiency may also be improved by selecting an overall production chain that can use a high yielding biomass crop.
For instance most oils seed crops only produce a few tonnes per hectare per annum, sugar and starch crops may generate 5 to 10 tonnes, while significantly greater yields come from woody plants – or from conventional crops such as cereals if the straw can be used. Greater utilisation of such materials depends on the development of second generation biofuels.
Even when these higher yielding methods come to market, land availability still sets limits to what may be produced. Suggestions have been made for the movement of biomass or biomass derived fuels from the more productive regions to the more industrialised countries. Should this type of movement be encouraged?
Value of preserving biodiversity through mechansims such as REDD Plus
In many potentially productive areas, preserving biodiversity may offer greater environmental and economic benefit than clearing forest to produce energy crops. Hence mechanisms need to be put into place to recognise the value of biodiversity These include the use of payments for ecosystem services, such as Reducing Emissions from Deforestation and Degradation (REDD) and REDD-plus (which places a greater value on biodiversity rather than just the quantity of carbon held in the forest system).