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SummaryBringing about more sustainable consumption patterns is an important challenge for society and science. In this article the concept of household metabolism is applied to analyzing consumption patterns and to identifying possibilities for the development of sustainable household consumption patterns. Household metabolism is determined in terms of total energy requirements, including both direct and indirect energy requirements, using a hybrid method. This method enables us to evaluate various determinants of the environmental load of consumption consistently at several levels-the national level, the local level, and the household level.The average annual energy requirement of households varies considerably between the Netherlands, the United Kingdom, Norway, and Sweden, as well as within these countries. The average expenditure level per household explains a large part of the observed variations. Differences between these countries are also related to the efficiency of the production sectors and to the energy supply system. The consumption categories of food, transport, and recreation show the largest contributions to the environmental load. A comparison of consumer groups with different household characteristics shows remarkable differences in the division of spending over the consumption categories.Thus, analyses of different types of households are important for providing a basis for options to induce decreases of the environmental load of household consumption. At the city level, options for change are provided by an analysis of the city infrastructure, which determines a large part of the direct energy use by households (for transport and heating). At the national level, energy efficiency in production and in electricity generation is an important trigger for decreasing household energy requirements.

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In The Netherlands Ranunculus hederaceus is a rare species that occurs in running waters. It appears to be confined to zones with a constant supply of mineral-poor groundwater, originating from highly fertilized fields,The relation between species performance and chemical composition of the water was investigated by means of response analysis. No relation was found unless the mineral content of the water was multiplied with stream velocity (yielding a measure for mineral supply per time unit). In the latter case significant correlations were found for calcium, bicarbonate, sodium, chloride and sulphate.We discuss whether low P-availability in the system could limit biomass production of Ranunculus hederaceus, although this appeared to be unlikely. Competition for light with algae and large helophytes is more likely to be a major reason for the absence of the species in stagnant waters.The situation near Oudemolen illustrates the indicative value of the species. Detailed investigations showed that artificial drainage changed the original mesotrophic conditions into eutrophic circumstances, which are much more favourable for this species. Hence, the increase of a rare plant species like Ranunculus hederaceus does not always indicate the well-being of a nature reserve.

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