Background Greenhouse gases (GHG), such as carbon dioxide (CO2) and methane (CH4), may be emitted at all life-cycle stages of a product, from extraction of raw material through to final disposal of materials. By relating the life cycle of materials to the waste hierarchy, an assessment of how each stage impacts on climate change can be made. The treatment and disposal of slowly biodegradable organic wastes (e.g. kitchen and garden waste) has a direct influence on GHG emissions. Solid waste management in Europe mainly produces GHG emissions through the decaying of biodegradable wastes under anaerobic conditions in landfills. This process emits about a third of anthropogenic emissions of CH4 in the EU. Currently, over 80% of waste in Greece is landfilled, presenting a significant problem with regards to the management and control of methane emissions. Objectives The WASTE-C-CONTROL project aimed to reduce GHG emissions by developing a software tool to assess, monitor, control and report on the emissions resulting from the entire life cycle of solid waste management activities. Using a systematic approach, different waste management options were assessed with regards to their GHG emissions, with the goal of enabling the project to identify procedures and practical tools within Local Action Plans (LAPs). The project aimed to reduce GHG emissions in pilot studies in three regions in Greece: Eastern Macedonia and Thrace, Western Macedonia, and Chania (Crete). Results The WASTE-C-CONTROL project developed a decision support software tool for monitoring GHG emissions from solid waste management activities during their whole life cycle. The software tool has assessed the entire range of the waste management practices, aimed to help authorities to identify best technological solutions with environmental and financial benefits as criteria at the local level. Alternative scenarios were developed for each one of the three participating regions (Eastern Macedonia and Thrace, Western Macedonia, and Chania) and the optimum one, in terms of both environmental and financial benefits, was selected for each region. Local Action Plans (LAPs), aiming to reduce GHG emissions from waste management activities at the local level, were developed on the basis of the results of the software tool’s implementation. The following GHG emissions reductions were achieved within the project’s lifetime: 5 285 tonnes CO2 eq in Eastern Macedonia and Thrace; 5 270 tonnes CO2 eq in Western Macedonia; and 1 269 tonnes CO2 eq in Chania. WASTE-C-CONTROL’s software tool enabled local authorities, companies and other stakeholders to substantially reduce GHG emissions resulting from their waste management activities. The tool provides decision support for the optimisation of waste management practices using a simulation environment, where an existing or desired regional or local waste management system can be designed by the user. The innovative aspect of the tool is the incorporation of a function to calculate the optimal values for the decision variables. In addition, the project team developed the WASTE-C-CONTROL iOS application for mobile phones as a useful and simplified tool for local authorities and other stakeholders, and also as a dissemination tool. Each LAP set specific quantitative goals for reductions in GHG emissions, specified the means to attain the reductions, the relevant investments needed, and a suggested schedule for these investments. According to the WASTE-C-CONTROL software tool results, the anticipated GHG emissions reductions from the implementation of the LAPS over a 20-year period were 1 600 kilotonnes CO2 eq (65%) for Eastern Macedonia and Thrace; 192 kilotonnes CO2 eq (36%) for Western Macedonia; and 75 kilotonnes CO2 eq (18%) for Chania. LAP short-term measures, to reduce GHG emissions at local and sectoral level, implemented in Eastern Macedonia and Thrace included the supply of recycling equipment (4 000 blue bins, 35 waste collection trucks and 4 bag openers), with recycling bins sited in the cities of Drama and Xanthi. Municipal solid waste streams were monitored and weighed at household level, for eight households over five months in Rodopi (with assistance from a local ecology group); the results showed that 67% of this household waste could be recycled or composted (achieving an estimated emissions reduction of 1.53 tonnes CO2 eq). An awareness-raising "recycling corner" was established by associated beneficiary DIAAMATH. The management of landfill gas at Kavala was improved through a monitoring programme and the installation of addition flares to burn off escaping methane (CH4) and carbon dioxide (CO2). In Chania, short-term LAP measures were organised by associated beneficiary DEDISA. These included the installation of new technology for sorting recyclables and the construction of transfer stations to reduce vehicle journeys. In Western Macedonia, associated beneficiary DIADYMA expanded the recycling programme, for example, with 4 900 new bins (to increase recovery of recyclables by 25%); purchased 14 waste collection vehicles; implemented an improved press system at the Kozani Transfer Station (with estimated emissions reduction of 3.31 tonnes CO2 eq); and purchased and installed ten biofilters, which reduced CH4 and CO2 emissions by 76% and 78.5%, respectively, in 2013. A number of information and public awareness activities were implemented through the LAPs in the three regions. These included the production of practical guidelines for waste-transfer station operators, the production public recycling guides, events for students and high school teachers, websites, and articles online and in printed media. Local authorities in the three regions have committed to continue the LAPs. These measures will help implement EU policies relating to solid waste management, packing and waste, and climate change and GHG emissions. A range of socio-economic benefits include savings resulting from increased recycling and composting rates, and the extended lifetime of existing landfills. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).