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Abstract: Society needs urgently good tools to understand the biosphere dynamics, become aware of Earth''s biophysical limits and make appraisals of environmental performance of human dominated systems. In this context, the Ecological Footprint (EF) was suggested as one of the most important tools. But, according to calculations based on Emergy Analysis, the indicators of EF could underestimate the problem of human carrying support. EF does not consider the work of untouched nature in productivity and ecosystems services. In order to improve the EF results, the present study suggests: (a) to include the ecosystems not considered in conventional EF i.e. tundra, deserts and areas covered by ice; (b) to consider the value of Net Primary Production (NPP) in Emergy units (seJm−2 year−1) as the base for the calculation of Equivalent Factors (EQF); (c) to account for the consumption of fossil energy used in collection, treatment and distribution of water for domestic use, for this the carbon emissions data (in tonCm−3 of water) were used. Introducing these changes to the conventional EF calculation and considering the Peruvian economy (in 2004) as the study case, the Biocapacity obtained was 14.31ghacapita−1 and the footprint was 6.68ghacapita−1. These values mean that Peru can support 2.14 times its population if the current life style is maintained, as opposed to the 4.0 times ratio obtained with a conventional EF calculation. [Copyright &y& Elsevier]

Aquaponics is a food production system that aims higher sustainability by integrating advantages gained from aquaculture and hydroponic production. Aquaponics aims to mimic the biological process that happens in the natural environment in a controlled production system. As it can be applied to small scales, aquaponics is considered an important alternative for urban regions, which have low availability of agricultural land and water resources. Furthermore, the advantage is that it is located close to final consumers. Aquaponics has been labeled as an environmentally friendly food production system, but its demand for energy and materials cast doubt on its sustainability. A systemic understanding of aquaponics production systems is needed to determine the magnitude and balance between its potentialities and constraints, in which emergy synthesis appears as a powerful tool for this purpose. This study applies emergy synthesis to assess the sustainability of two different (scale and marketable products) urban aquaponics farms in Brazil, but differently from other emergy studies, ecosystem services and disservices are included in the analysis as an attempt to represent the system performance holistically. Results show that the type of materials used in aquaponics infrastructures has the highest influence on total emergy demand. Surprisingly, electricity and fish feed showed a low influence on the total emergy, reinforcing the idea that aquaponics systems have a more efficiency feeding management than traditional aquaculture systems. Besides producing vegetables and fish, the inclusion of ecosystem services highlights the importance of aquaponics for educational and tourism purposes. Finally, the obtained indicators from modeling scenarios revealed that replacing the water source and some materials deserves priority attention to increase the sustainability of urban aquaponics farms. [ABSTRACT FROM AUTHOR]

The agriculture ecosystem is very important, complex and humankind largest engineered ecosystem providing essential ecosystem services as well as many disservices, depending on management and agriculture practices. Due to the complications, uncertainties, overestimations and double counting in ecosystem services accounting frameworks, (1) this study establishes a non-monetary "donor side" ecosystem services valuation methods constructing the emergy-based agriculture ecosystem services framework, propose the ecosystem services calculations method and classify the services into direct, indirect and existing services. (2) Further, it assess the sustainability of agriculture ecosystem nature's and human's contribution in the services through RNP% (renewability) and NRP% (non-renewability). Taking the case of agriculture ecosystem in Bahawalnagar, Pakistan, five agriculture cultivating ecosystems including wheat, rice, sugarcane, maize and cotton are selected for services and disservices valuation. (3) A total of eleven ecosystem services were evaluated in which four belongs to direct services category such as biomass increase, carbon sequestration, soil building and groundwater recharge; four are included in indirect services category (dis-services) such as human health and ecosystem quality losses due to greenhouse gases emissions, soil, water pollution and soil erosion increase; existing services includes climate regulation, agro-tourism & recreational, cultural and educational values. (4) The results indicate that the green revolution in agriculture ecosystem encourage and increase dependency of human inputs such as synthetic fertilizers, pesticides and energy which produces higher productions but on other side it produces dis-services which is harmful for humans and other ecosystems diversity. The method proposed by this study can deliver improved theoretical and policy insights to ecosystem services accounting for agriculture ecosystem, as the agriculture ecosystem is the major source of food but along with it drive's significant environmental degradation. [ABSTRACT FROM AUTHOR]