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- ItemEmbodied crop calories in animal products(Bristol : IOP Publishing, 2013) Pradhan, Prajal; Lüdeke, Matthias K.B.; Reusser, Dominik E.; Kropp, Jürgen P.Increases in animal products consumption and the associated environmental consequences have been a matter of scientific debate for decades. Consequences of such increases include rises in greenhouse gas emissions, growth of consumptive water use, and perturbation of global nutrients cycles. These consequences vary spatially depending on livestock types, their densities and their production system. In this letter, we investigate the spatial distribution of embodied crop calories in animal products. On a global scale, about 40% of the global crop calories are used as livestock feed (we refer to this ratio as crop balance for livestock) and about 4 kcal of crop products are used to generate 1 kcal of animal products (embodied crop calories of around 4). However, these values vary greatly around the world. In some regions, more than 100% of the crops produced is required to feed livestock requiring national or international trade to meet the deficit in livestock feed. Embodied crop calories vary between less than 1 for 20% of the livestock raising areas worldwide and greater than 10 for another 20% of the regions. Low values of embodied crop calories are related to production systems for ruminants based on fodder and forage, while large values are usually associated with production systems for non-ruminants fed on crop products. Additionally, we project the future feed demand considering three scenarios: (a) population growth, (b) population growth and changes in human dietary patterns and (c) changes in population, dietary patterns and feed conversion efficiency. When considering dietary changes, we project the global feed demand to be almost doubled (1.8–2.3 times) by 2050 compared to 2000, which would force us to produce almost equal or even more crops to raise our livestock than to directly nourish ourselves in the future. Feed demand is expected to increase over proportionally in Africa, South-Eastern Asia and Southern Asia, putting additional stress on these regions.
- ItemComment on 'High-income does not protect against hurricane losses'(Bristol : IOP Publishing, 2017) Rybski, Diego; Prahl, Boris F.; Kropp, Jürgen P.Geiger et al (Environ. Res. Lett. 2016 11 084012) employ two functional relationships to characterize hurricane damage in the USA—either based on GDP (one exponent) or on per capita GDP and population (two exponents). From the Akaike Information Criterion the authors cannot reject the former kind in favor of the latter. The different approaches, however, lead to divergent projections of future hurricane losses. In this comment, we argue that there is no rigorous evidence in [1] to give preference to one or the other approach, and the conclusion that high-income does not protect against hurricane losses needs to be revisited. As a perspective, it needs to be mentioned that the previously published relationship between GDP and population could unify both approaches.