Internal and external green-blue agricultural water footprints of nations, and related water and land savings through trade

By Marianela Fader, Dieter Gerten, M. Thammer, Jens Heinke, H. Lotze-Campen, Wolfgang Lucht, W. Cramer. 2011

247 citations recorded by the source corpus.

Abstract. The need to increase food production for a growing world population makes an assessment of global agricultural water productivities and virtual water flows important. Using the hydrology and agro-biosphere model LPJmL, we quantify at 0.5° resolution the amount of blue and green water (irrigation and precipitation water) needed to produce one unit of crop yield, for 11 of the world's major crop types. Based on these, we also quantify the agricultural water footprints (WFP) of all countries, for the period 1998–2002, distinguishing internal and external WFP (virtual water imported from other countries) and their blue and green components, respectively. Moreover, we calculate water savings and losses, and for the first time also land savings and losses, through international trade with these products. The consistent separation of blue and green water flows and footprints shows that green water globally dominates both the internal and external WFP (84 % of the global WFP and 94 % of the external WFP rely on green water). While no country ranks among the top ten with respect to all water footprints calculated here, Pakistan and Iran demonstrate high absolute and per capita blue WFP, and the US and India demonstrate high absolute green and blue WFPs. The external WFPs are relatively small (6 % of the total global blue WFP, 16 % of the total global green WFP). Nevertheless, current trade of the products considered here saves significant water volumes and land areas (~263 km3 and ~41 Mha, respectively, equivalent to 5 % of the sowing area of the considered crops and 3.5 % of the annual precipitation on this area). Relating the proportions of external to internal blue/green WFP to the per capita WFPs allows recognizing that only a few countries consume more water from abroad than from their own territory and have at the same time above-average WFPs. Thus, countries with high per capita water consumption affect mainly the water availability in their own country. Finally, this study finds that flows/savings of both virtual water and virtual land need to be analysed together, since they are intrinsically related.

Subfields: Environmental Engineering, Ocean Engineering, Water Science and Technology

View Paper: https://www.semanticscholar.org/paper/7aa2c3ded302873007646f159f4c882e34197aa5

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Environmental Engineering

In Ocean Engineering

In Water Science and Technology

Citations in the corpus

Reserves and trade jointly determine exposure to food supply shocks (2016, background): “…and externalization of environmental impacts (Galloway et al 2007, O’Bannon et al 2014), virtual water and land trade (Hoekstra and Chapagain 2008, Fader et al 2011), and the overall geographic disconnection between consumers and the environment that supports them (Carr et al 2013,MacDonald et…”
National water footprint accounts: the green, blue and grey water footprint of production and consumption (2011, background): “contemporary study by Fader et al. (2011), who estimate the global green and blue water footprint of consumption showing the internal and external water footprint per country.”
Global Monthly Water Scarcity: Blue Water Footprints versus Blue Water Availability (2012, methodology): “water use studies [11–17], we measure water use in terms of”
Spatial decoupling of agricultural production and consumption: quantifying dependences of countries on food imports due to domestic land and water constraints (2013, methodology): “…in export countries to produce agricultural products imported and consumed by the US exceed 70 km3 (Chapagain and Hoekstra 2004), and Japan, China and Mexico import agricultural products that need the use of almost 30 Mha land in other countries (so-called ‘virtual land imports’, Fader et al 2011).”
Agricultural trade and virtual land use: The case of China's crop trade (2013, background): “With regards o land, Fader et al. (2011) found considerable land savings assoiated with international trade of crop products.”
Imported water risk: the case of the UK (2016, background): “Various global assessments of the WFs of nations and international VW flows have been published: Hoekstra and Hung (2002), Hoekstra and Chapagain (2007b, 2008), Fader et al (2011), Mekonnen and Hoekstra (2011b), Hoekstra and Mekonnen (2012) and Chen and Chen (2013).”
Rethinking Agricultural Trade Relationships in an Era of Globalization (2015, methodology): “X http://bioscience.oxfordjournals.org virtual water footprint of crop and livestock exports (e.g., Fader et al. 2011, Dalin et al. 2012) highlight the shared nature of water resources among countries (Hoekstra and Mekonnen 2012).”
Virtual water trade flows and savings under climate change (2013, background): “Of particular importance, the international trade in food commodities has been shown to save water (Chapagain et al., 2006; Yang et al., 2006; Fader et al., 2011), increasingly so over the last few decades (Dalin et al., 2012; Konar et al., 2012).”
Measuring telecouplings in the global land system: A review and comparative evaluation of land footprint accounting methods (2015, unknown): “Physical accounting studies sometimes simplify by assuming the exporting country to be the producing country (Fader et al., 2011; Würtenberger et al., 2006).”
The blue water footprint of electricity from hydropower (2011, background): “The aggregated blue water footprint of the 35 selected hydropower plants is 90 Gm(3)/yr, which is equivalent to 10% of the blue water footprint of global crop production in the year 2000 (Mekonnen and Hoekstra, 2011; Fader et al., 2011).”
Temporal dynamics of blue and green virtual water trade networks (2012, background): “[7] The importance of considering the water source in the virtual water literature has been highlighted [Hoekstra and Chapagain, 2008; Aldaya et al., 2010; Siebert and Döll, 2010; Fader et al., 2011].”