CO emissions from land conversion for energy crops Tonnes of CO2 per hectare
2
Peatland tropical rainforest
South East Asia - Oil palm
Lowland tropical rainforest
Peatland natural rainforest
Natural rainforest
Logged-over forest
Degraded land
Rubber plantation
-90 697 1 797 Brazil - Sugarcane Land conversion and greenhouse gas emissions
The conversion of high carbon-storage ecosystems, such as tropical forest, savannah and peatland into biofuel plants, can neutralise any GHG emission reductions achieved by replacing
fossil fuels with biofuels, and even lead to a net increase in CO2 emissions.
Biofuels, in the use phase, emit the carbon that has been previously absorbed during plant growth. Inputs during cultivation and conversion need to be accounted for. However, the bulk of GHG emissions are related to land-use change. The carbon footprint varies considerably depending on the type of land converted, the type and yield of the feedstock (tonnes per hectare), as Figure 3.1.4 shows. It is therefore key that any GHG analysis takes into account the entire life-cycle of biofuels, including impacts from land-use change. As illustrated, these CO2
emissions range across different types of land and crops (Figure 3.1.5). Figure 3.1.5 CO2 emissions from land conversion for energy crops 23
Logged-over woodland (Bioshape)
-13
Tanzania - Jatropha Miombo
woodland (wet) (Bioshape)
154
Woody cerrado and cerrado
165
Degraded pasture
-58 Cropland (soy) -12 581 85 854 735
Tropical moist forest
1 580 748 433
87
Brazil - Soybean
Tropical rainforest
Amazonian rainforest
Grassy cerrado
Grassland
23
woodland (dry) (Bioshape) Cropland
75 -140
Source: R.Hoefnagels et al.: Greenhouse gas footprints of different biofuel production systems, Renewable and Sustainable Energy Review, 2010.