# Implementation of the 3-30-300 Green City Concept: Warsaw Case Study
## 4 Discussion
Taking into account the diagnosed situation, but also the policy of the city authorities, it seems that two main directions of action are justified in order to effectively introduce changes. Firstly, community activities. For many years, as part of the Million Trees for Warsaw project [27], every resident has been able to nominate a place where they would like to plant a tree. Owing to our research, we know where trees are most needed. These expectations can be reported using a special application provided by the City Hall. A similar goal can be achieved by reporting tree planting initiatives as part of the annual municipal budget. The second line of action is the need to develop local spatial development plans that reserve space for parks in intensively developed areas. Significantly, the areas identified in our research as having the worst green cover (e.g., Bemowo, Ursus) have only 30-40% of their area covered by such plans. Companies that make money from building homes are taking advantage of this situation. In order to make city authorities aware of the need for action, but also to identify specific areas suitable for green infrastructure, our next research will focus on multi-criteria spatial analysis to identify areas in the city that can be used for parks and squares. The results of the analysis of residents' access to urban greenery in Warsaw, according to the 3-30-300 concept, can make a valuable contribution to urban planning and urban ecology. An approach that takes into account different criteria for access to green space can not only improve the aesthetics of the city, but also has a direct impact on the mental and physical health of residents. Green spaces promote physical activity, reduce stress, and improve wellbeing. A multifaceted approach to the analysis of urban greenery also shows that surveying and evaluating only on the basis of a single criterion, such as distance to a park, gives a false picture of accessibility to greenery and cannot be a measure to assess whether a city is green. The proposed implementation of the 3-30-300 concept is universal and can be applied to studies in other cities. Owing to spatial analyses, in the future, it will become possible both to compare Warsaw with other cities and to develop effective strategies for increasing the accessibility and quality of green areas. It is worth emphasizing that the use of spatial analyses and showing the spatial distribution of different aspects of access to greenery in the city enable local intervention, precisely in those places where access to specific forms of greenery is unsatisfactory. It is worth noting that the analyses performed can be used in the implementation of practical assumptions of the European Parliament's law regarding nature restoration [39; 40]. The objective of this law is to contribute to the  
Figure 17: Photo (**a**) shows a newly built housing estate without green infrastructure, while (**b**) represents an old Warsaw housing estate with lots of greenery. continued, long-term, and sustainable recovery of a biodiverse and resilient nature on EU land and sea through ecosystem restoration, as well as to the achievement of the EU's climate change mitigation and adaptation objectives and the fulfilment of the Union's international commitments. It proposes legally binding targets for ecosystem restoration in the European Union; one of the main goals is to restore at least 30% of land areas by 2030.