Spatial justice links together social justice and space, most notably in the works of geographers David Harvey and Edward W. Soja. The organization of space is a crucial dimension of human societies and reflects social facts and influences social relations. Consequently, both justice and injustice become visible in space. Therefore, the analysis of the interactions between space and society is necessary to understand social injustices and to formulate territorial policies aiming at tackling them. It is at this junction that the concept of spatial justice has been developed.
Social justice
According to this political theory, space being a fundamental dimension of human societies, social justice is embedded in it. So the understanding of interactions between space and societies is essential to the understanding of social injustices and to a reflection on planning policies that aims at reducing them. This reflection can be guided by the concept of spatial justice, which ties Social Justice with space. Spatial justice is a crucial challenge because it is the ultimate goal of many planning policies. However, the diversity of definitions of "Justice", is high and the political objectives of regional planning or urban planning can be quite different and even contradictory. Therefore, it is important to analyze the concept of spatial justice, which is still rarely questioned to the extent that it has been taken for granted. These past few years, several events and publications have demonstrated the rising interest of human and social sciences for the concept of spatial justice.
The concept of spatial justice opens up several perspectives for social sciences. Building on the work of several famous Justice philosophers, two contrasting approaches of justice have polarized the debate: one focuses on redistribution issues, the other concentrates on decision-making processes. A first set of approaches consists in asking questions about spatial or socio-spatial distributions and working to achieve an equal geographical distribution of society's wants and needs, such as job opportunities, access to health care, good air quality, et cetera. This is of particular concern in regions where the population has difficulty moving to a more spatially just location due to poverty, discrimination, or political restrictions. Even in free, developed nations, access to many places are limited. Geographer Don Mitchell points to the massprivatization of once-public land as a common example of spatial injustice. In this distributive justice perspective, the access to material and immaterial goods, or to social positions indicates whether the situation is fair or not. At the scale of urban space, questions of accessibility, walkability and transport equity can also be seen as matters of distribution of spatial resources. Another way of tackling the concept of spatial justice is to focus on decision-making procedures: this approach also raises issues of representations of space, of territorial or other identities and of social practices. For instance, focusing on minorities allows to explore their spatial practices but also to investigate how these are experienced and managed by various agents: this may lead to reveal forms of oppression or discrimination that a universalist approach might disregard otherwise. In sum, depending on the chosen approach, either questions are asked about spatial distributions because justice is evaluated from "results", or questions are asked about space representations, identities and experiences because justice is defined as a process. Spatial justice stands as a unifying concept for the social sciences: its coherence stems from a reflection on the modalities of the political decision-making and on the policies implemented in order to improve spatial distributions.
Environmental justice
The emergence of the concept of sustainable development has also fostered a debate on environmental equity. It questions our ontological relationship to the world, and the possibility of a fair policy addressing the needs of mankind, present and future, local and global, and of new forms of governance. The notion of "Environmental Justice" was created in the 1970s–1980s in North American cities to denounce the spatial overlapping between forms of racial discrimination and social-economic exclusion, industrial pollutions and vulnerability to natural hazards.
