Agrofuels and Bioenergy
The IAASTD notes that the frequently quoted positive climate effects of biofuels are controversial. When biofuels are burnt, only as much CO2 as was previously absorbed by the plant is released into the atmosphere. However, the cultivation of the crops and their processing into fuel requires intensive energy input. Enormous CO2 emissions occur if forests are cleared to generate new land, either directly for the cultivation of energy crops or indirectly to replace land for food crops that was converted to biofuels production elsewhere. This can reduce the positive effects compared to oil or, depending on the plant species and location, can even exceed the emissions resulting from oil. The IAASTD calculates that two-thirds of the world’s agricultural land would be required for the cultivation of renewable resources equivalent to just 20% of the global crude oil consumption."Current trends indicate that a large-scale expansion of production of 1st generation biofuels for transport will create huge demands on agricultural land and water - causing potentially large negative social and environmental effects, e.g., rising food prices, deforestation, depletion of water resources that may outweigh positive effects." (Global, p. 422)
Competition for soil and water
In any event, given the limited availability of water resources and land suitable for cultivation, biofuels directly compete with food cultivation. The production of agrofuels promotes industrial monocultures and enhances their negative impact on rural areas and employment, as well as on the environment."There are also eco-ethical considerations; putting more ecologically fragile and necessary lands into production of biofuels; whether oil palm production in Southeast Asia at the expense of jungles, or soybean production at the expense of rangeland or rain forest. It may not be morally justifiable to purchase oils for biofuels from areas where the environment is being negatively exploited." (North America & Europe, p. 219)In particular, the IAASTD warns against the expansion of renewable resource cultivation in ecologically valuable natural areas, as this could pose an additional threat to biodiversity. The report is cautious in its assessment of the technical feasibility and efficiency of so-called second-generation biofuels that are produced from algae or the cellulose of trees, shrubs, straw and grass instead of food crops. The problem of competition for increasingly scarce soil and water remains.
Biofuels are only a small but rapidly growing part of bioenergy production. Worldwide, three billion people use wood for cooking and heating.
Many traditional forms of combustion of wood and charcoal, crop residues and dung are energy inefficient, are harmful to health and climate, and deprive soils of organic matter. In some regions, particularly in Africa, the overuse of firewood is also threatening the already sparse tree populations, while collecting wood consumes working time that could better be invested elsewhere. The IAASTD therefore considers it a crucial task for the future to optimise the traditional use of bioenergy and in particular to develop new energy sources, such as solar cookers for poor rural communities."While biofuels may provide prospects for the development of new sources of energy from agriculture, there is the threat of converting natural forests and agricultural lands into monoculture plantations. Furthermore, there is the issue of corporate or community ownership of such initiatives. These developments may have implications for food security, biodiversity, sustainability and livelihoods. Establishing decentralised, locally-based, highly-efficient energy systems is one option to improve livelihoods and reduce carbon emissions." (East and South Asia and the Pacific Report, p. 64)