CO2ZW: ابزار اثرات کربن برای مدیریت زباله های شهری برای گزینه های سیاسی در اروپا . موجودی کشورهای مدیترانه ای

In the frame of the European project titled “Zero Waste” (1G-MED08-533), a tool has been developed called CO2ZW for estimating the GHG emissions for the management of MSW at the municipal, regional or national levels with small amounts of input data. The objective of this paper is to demonstrate that the CO2ZW tool allows us to inventory and monitor GHG emissions from MSW following the IPCC guidelines for national inventories and the principles of life cycle assessment (LCA). The CO2ZW tool includes the key stages and parameters for calculating GHG emissions and includes several advantages regarding the implementation of the default values of the Mediterranean European countries, an improvement in accessibility (online free access) and two approaches for calculating GHG emissions from landfills. The results of this paper show that for countries with medium and high rates of deposition, implementation of the European policies limiting waste in landfills can contribute to mitigate climate change in a remarkable way. With the CO2ZW tool, it is possible to evaluate waste management choices depending on waste management infrastructures and waste policies, along with the quantification of GHG emissions from MSW management, which is essential to guide waste policy options and climate change solutions.

With the global urban population now exceeding 50%, the inhabitants of cities are recognized as the major drivers of global greenhouse gas (GHG) emissions. Moreover, as centres of wealth and creativity with high population densities and economies of scale, cities must play a significant role in tackling global climate change (Kennedy et al., 2009). Concerns regarding global climate change have resulted in the development of a variety of solutions to monitor and reduce emissions on the global and local scales. For instance, the EU energy and climate package has set goals to reduce these GHG emissions by 20% by 2020, with an option to increase the reduction target to 30% if a comprehensive international agreement is reached, and the results of an analysis of several options have been recently published (European Commission, 2012). Municipalities are often in a position to make decisions that affect the local emissions in the short, medium and long terms. Therefore, the possibility of quantifying local emissions has become an important element in understanding the problem (D’Avignon et al., 2010), and there is a crucial need to present a suitable method for accounting for GHG emissions at the city level so that urban decision makers can develop appropriate policies to reduce their total GHG emissions (Xi et al., 2011). Over the last 20 years, GHG emissions have resulted from two sets of opposing factors: those increasing the GHG emissions and those helping in mitigating emissions (Dimitroulopoulou and Ziomas, 2011). In this sense, at a global scale, the waste management sector makes a relatively minor contribution to greenhouse gas (GHG) emissions, which is estimated to be approximately 3–5% of the total anthropogenic emissions in 2005. However, the waste sector is in a unique position to transition from being a minor source of global emissions to becoming a major saver of emissions (United Nations Environmental Program (UNEP), 2010) due to prevention, reuse and recycling. Although minor levels of emissions are released through waste treatment and disposal, the prevention and recovery of waste (i.e., as secondary materials or energy) avoids emissions in all other sectors of the economy (United Nations Environmental Program (UNEP), 2010). Waste management (WM) has been a focus of the environmental policies of the European Union (EU) since the early 1970s, and their targets and objectives have increased each year. These policies, which require more efforts to reduce, reuse and recycle waste, are helping to close the loop on the use of materials throughout the economy, including life cycle thinking to waste management (Pires et al., 2011). With the intention of improving these principles of reuse and recycling, the project titled “Low Cost—Zero Waste Municipality” bearing the acronym “ZERO WASTE” (1G-MED08-533) was started in 2009, and for 36 months, the partnership including 7partners from Greece, Italy, Slovenia and Spain has been working on the dissemination of knowhow and data collection to facilitate municipalities in the application of methods to decrease waste. The project aims at developing an integrated zero waste management system for municipalities based on reusing, recycling and reducing waste that ends up in landfills. As a consequence of the project and previous studies (Fragkou et al., 2010, Rives et al., 2010, Iriarte et al., 2009 and Muñoz et al., 2004), recent information regarding quantity and quality of the waste management sector of the partners’ countries was collected and inventoried. Taking into account the possibility of having to address climate change and the variable quality of the information that has been collected over the years, one of the objectives of project ZERO WASTE was to develop a tool to inventory, describe and quantify the GHG emissions for the management of MSW and to aid in the decision process involved in generating local policies of waste management. The new tool named “Carbon Footprint Tool for Waste Management in Europe” (from now on, CO2ZW) will allow municipalities to inventory and monitor the GHG emissions for the management of MSW following the Intergovernmental Panel on Climate Change (IPCC) (2006) guidelines for national inventories and the principles of life cycle assessment (LCA) (ISO 14040, 2006); to evaluate MSW plans, programs, projects or policies at different scales (i.e., national, regional, municipal); and to detect weak points and potential areas for the improvement of MSW management. Life cycle thinking in waste management systems has been used as an input to decision making concerning resource priority (Cherubini et al., 2009), and the popularity of applying the LCA methodology to analyze MSW management strategies is illustrated by the numerous published studies as well as by the substantial number of LCA computer models addressing MSW management (Eriksson and Bisaillon, 2011). However, most of these models and tools have been developed to work at the scientific level, and a large quantity of data is required, which in most cases, is not available for local authorities. The CO2ZW tool requires a limited amount of input data and performs calculations that are easy and simple; thus, all stakeholders that are involved in the waste management sector (including technicians, consultants, NGO’s or politicians) are able to calculate GHG emissions. CO2ZW also provides three performance indicators to compare the performances of the municipalities with the targets prescribed in the European waste management framework (the overall rate of recycling and the amount of landfilled biodegradable waste and mixed waste without previous treatment sent to landfill). These indicators allow us to evaluate the municipality’s performance of legal targets and strategies of climate change mitigation at the sametime. In this paper, we present and describe the CO2ZW tool. We also conduct a sensitivity assessment of CO2ZW to explore uncertainties and to detect critical parameters. Then, we compare the new tool with several tools that are already available. Finally, we evaluate the case of Spain under several scenarios to show the potential abilities of the tool and the GHG emission mitigation.

This paper presents a new, user-friendly and free access tool from http://co2zw.eu.sostenipra.cat/ once a previous registration of the user is completed at: http://sostenipra.ecotech.cat, for calculating the GHG emissions from waste management processes from a life cycle perspective. This tool is suitable for guiding policies in waste management, and it has been developed by and for studies and policy makers that need to evaluate the GHG emissions at the municipal, regional or national levels with a small amount of required input data (indicated in Table 1). In addition, quick calculations can be performed with the support of graphical information (see Fig. 1). A comparison among the most common models has shown that the CO2ZW tool includes the key stages and parameters for calculating the GHG emissions and also has several advantages, such as the implementation of default values for Mediterranean European countries (Spain, Italy, Greece and Slovenia), the improvement in the accessibility and versatility and the inclusion of two approaches of GHG calculations from landfills. The sensitivity assessment conducted with the Spanish default values and the evaluation of several alternative strategies for Spain has also shown that the main stages affecting the GHG emissions are recycling and landfills. For the material recycling processes, there is a lack of a common methodology to quantify the impacts of the recovered materials, and more research in this area is needed. The methodology used to quantify the GHG emissions from landfills has been proven in the international scientific framework, and the variability in the results is related to the operation of the waste sector and to the policies adopted. In this sense, recent reports from the European Environment Agency (EEA) on “The road from landfilling to recycling: common destination, different routes” evaluates the waste management choices of the EU countries depending on the existing waste management facilities, the infrastructure and the governance structures and establishes three groups of countries defined by a diversion strategy for MSW (European Environment Agency (EEA), 2007): low (Denmark), medium (Spain) and high (Greece) levels of landfills. Considering the results for Spain, it can be concluded that there is high potential for climate change mitigation at the European level through the complementary solutions of incineration, biological treatments and the increase of selective fractions, along with diminishing levels of landfills, especially for countries in the second and third groups, which are mainly the East and Southern European countries.