Dear Sören. Thank you very much for the detailed information on this World Bank effort! Splendid. Ab bit more on the Water Footprint of Energy: It is generally accepted that emissions of greenhouse gasses, such as CO2 from fossil energy carriers, are responsible for anthropogenic impacts on the climate system. In this context, there has been a remarkable shift in policy attitudes towards CO2-neutral energy carriers such as biomass. The production of biomass for food and fibre in agriculture requires about 86% of the worldwide freshwater use. In many parts of the world, the use of water for agriculture competes with other uses such as urban supply and industrial activities. In a scenario of increasing degradation and decline of water resources, a shift from fossil energy towards energy from biomass puts additional pressure on freshwater resources. There are large differences among the water footprints for specific types of primary energy carriers. As a whole, the water footprint of energy from biomass is 70 to 400 times larger than the water footprint of the other primary energy carriers (excluding hydropower). Nevertheless, it depends on crop type, agricultural production system and climate. The trend towards larger energy use in combination with increasing contribution of energy from biomass to supply will bring with it a need for more water. This causes competition with other claims, such as water for food crops. When crops are used for bio-energy, it is more efficient to use the total biomass, including stems and leaves, to generate electricity than to use only a fraction of the crop (its sugar, starch or oil content) to produce biofuel. The weighted average water footprint of energy (m3/GJ) is a factor two to four smaller for bio-electricity than for bio-ethanol or biodiesel. This is because for electricity, the total biomass can be used; whereas for ethanol or biodiesel only the sugar or starch respectively the oil fraction of the yield can be used. In general, when considering biofuels for transportation, the water footprint of bio-ethanol is smaller than the water footprint of biodiesel. More information can be accessed at: http://www.waterfootprint.org/?page=files/Water-energy Also of interest may be this recent publication on Bioenergy and Water: Dallemand, J.F. and Gerbens-Leenes, P.W. (eds.) (2013) Bioenergy and water, Joint Research Centre, European Union, Ispra, Italy. available at (size of pdf file is 9 MB): www.waterfootprint.org/Reports/Leenes-et-al-2013.pdf Best, Markus

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Dear Sören. Thank you very much for the detailed information on this World Bank effort! Splendid. Ab bit more on the Water Footprint of Energy: It is generally accepted that emissions of greenhouse gasses, such as CO2 from fossil energy carriers, are responsible for anthropogenic impacts on the climate system. In this context, there has been a remarkable shift in policy attitudes towards CO2-neutral energy carriers such as biomass. The production of biomass for food and fibre in agriculture requires about 86% of the worldwide freshwater use. In many parts of the world, the use of water for agriculture competes with other uses such as urban supply and industrial activities. In a scenario of increasing degradation and decline of water resources, a shift from fossil energy towards energy from biomass puts additional pressure on freshwater resources. There are large differences among the water footprints for specific types of primary energy carriers. As a whole, the water footprint of energy from biomass is 70 to 400 times larger than the water footprint of the other primary energy carriers (excluding hydropower). Nevertheless, it depends on crop type, agricultural production system and climate. The trend towards larger energy use in combination with increasing contribution of energy from biomass to supply will bring with it a need for more water. This causes competition with other claims, such as water for food crops. When crops are used for bio-energy, it is more efficient to use the total biomass, including stems and leaves, to generate electricity than to use only a fraction of the crop (its sugar, starch or oil content) to produce biofuel. The weighted average water footprint of energy (m3/GJ) is a factor two to four smaller for bio-electricity than for bio-ethanol or biodiesel. This is because for electricity, the total biomass can be used; whereas for ethanol or biodiesel only the sugar or starch respectively the oil fraction of the yield can be used. In general, when considering biofuels for transportation, the water footprint of bio-ethanol is smaller than the water footprint of biodiesel. More information can be accessed at: http://www.waterfootprint.org/?page=files/Water-energy Also of interest may be this recent publication on Bioenergy and Water: Dallemand, J.F. and Gerbens-Leenes, P.W. (eds.) (2013) Bioenergy and water, Joint Research Centre, European Union, Ispra, Italy. available at (size of pdf file is 9 MB): www.waterfootprint.org/Reports/Leenes-et-al-2013.pdf Best, Markus