Background Climate change is one of the most challenging environmental, social and economic threats we face today. The international community is trying to tackle this problem through the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Global warming is a reality and, as confirmed by the Intergovernmental Panel on Climate Change (IPCC), its effects are already visible in some areas of the world. In some European urban areas, moreover, the negative impacts of this environmental problem are already emerging: higher average temperatures and the increased concentration of air pollutants. The urban population has doubled globally over the last 50 years, and it is estimated that two-thirds of the world's population will be living in cities by 2030. The need to address climate change in an urban context will therefore play important role in an overall strategy to tackle climate change. Objectives The project aimed to tackle two environmental problems through an integrated policy: climate change (both the mitigation and adaptation effects of urban forestation) and air quality (the depuration potential of plants). The project foresaw the dissemination of public-private partnership tools, developed within the framework of corporate social responsibility experiences, and the distribution of specific guidelines. Specifically, the project planned to develop a public-private partnership model for urban forestation through the adoption of the ‘green areas inner-city agreement’ (GAIA). This was expected to include three specific protocols for green urban areas covering management, monitoring and mapping. The three protocols aimed to: Develop a model of environmental governance that merges the mitigation and adaptation effects of climate change (and show how they impact on air quality); Demonstrate the feasibility of local policies tackling climate change through the development partnerships between private and public bodies for the management of green urban areas; Initiate a process for assisting public administrations in promoting co-responsibility by introducing an innovative management tool that fosters tree planting in urban areas to compensate for the construction of infrastructure; Define a common and replicable methodology for calculating the greenhouse gases and air pollutants sequestration potential of trees; and Offer an instrument that local businesses can apply to offset their carbon footprint.Results The GAIA project has developed an instrument by which local enterprises and firms can decrease their carbon footprint and, at the same time, generate environmental and social benefits for the community. Even though it was difficult to engage the private sector in these kind of initiatives, mainly due to the economic crisis, the project succeeded in persuading 18 private companies to participate. Such involvement enabled around a thousand trees to have been planted in Bologna by the end of the project with the foreseen target of 3 000 due to be reached in the following two years. It also succeeded in drawing up the foreseen protocols: a technical protocol for evaluating trees in terms of CO2 sequestration and air pollutant removal as well as an analysis of eco-physiological threats of 20 tree species; and a management protocol for identifying juridical characteristics of the private-public agreement. Moreover, the project designed a carbon toolkit for calculating environmental targets in terms of CO2. Finally, the project carried out a survey of the best national and international practices in the field of public-private partnership and gathered up its findings in a ‘State of the Art Report’. Guidelines for the internationalisation of the project were also drawn up. Its dissemination campaign included a conference in Brussels and the production of an appealing video and calendar. In the long term, more effective urban city planning is expected. GAIA also enhanced the role of local authorities as key actors responsible for the implementation of actions that can mitigate the impact of climate change on the urban environment. The involvement of local companies in the partnership is also expected to increase their sense of responsibility for their surroundings. The GAIA partnership will continue after the project in order to ensure that urban forestation becomes a long-term goal of the municipality of Bologna. It will also help expand activities to other towns in Italy and beyond. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).