France has long been alarmed at the artificialization of a department every ten years. However, we are still far from putting an end to it, as the President of the Republic pledged during his election campaign. This is why we must welcome the return of this issue to the political agenda, at the initiative of the Minister for Ecological and Solidarity Transition, who has just launched a debate on the taxation of land artificialisation.
But what exactly should be taxed? Is artificialisation, the act of transforming natural or agricultural areas into artificial spaces (urban, transport, leisure and extraction areas), simply synonymous - as we often hear - with the concreting of agricultural land to build housing? A study by IDDRI, published at the beginning of the year, provides some answers.
Ahe Minister Nicolas Hulot wants to fight against the "folie des grandeurs" of real estate developers and remedy the decrease in agricultural land, and therefore plans to tax "concrete mixers" to preserve biodiversity. "I'm looking at a new source of funding to fight against soil artificialisation and to finance biodiversity conservation". he explained to the newspaper Le Parisien on October 11th. An awareness and position that would be related to the Ifop survey published by the environmental NGO WWF Francewhich reveals that 78% of the French would be in favour of a moratorium on the artificialisation of agricultural land from 2020.
Artificialization is the result of a process of progression and regression of a wide variety of land uses. These land uses are of varying interest for biodiversity, including in urban areas. This potential for biodiversity is highly dependent on the way in which these areas are managed.
A policy that seeks to protect biodiversity should therefore focus on how to design, develop and manage these different spaces - as much, if not more, than on how to contain urbanization.
Policy evaluation struggles to make the link between biodiversity actions, expected targets and outcomes. While biodiversity-oriented policy measures are put forward, at the same time ecosystems continue to be degraded and pressures on biodiversity are even increasing - without really questioning the accountability of public policies. How can we really evaluate the public policies implemented, the means employed, and their effects on biodiversity?
READ ALSO IN UP' : Artificialization of land: biodiversity at risk!
Emblematic image of a sprawling suburb in the USA, taken from Gregory Greene's film "The End of Surburbia".
A fine analysis of the dynamics of artificialisation
Thanks to the data [1] very detailed data available on the Île-de-France region - data that unfortunately does not exist at the national level the DDRI study [2] analyses the dynamics of artificialisation between 1999 and 2012 in this territory. The figure below shows the changes in land use, distinguishing between types of areas that do not have the same interest for biodiversity :
- Woodlands, which are important reservoirs of biodiversity when managed appropriately.
- Natural open spaces, such as moors or natural meadows, which are essential habitats for many species.
- Agricultural areas, for crops and pastures, which have a variable biodiversity potential depending on practices, low for example in the case of intensive monocultures and simplification of the landscape.
- Artificialized open spaces, i.e. urban green spaces, sports fields, lawns bordering activity zones or transport infrastructures, all of which can be interesting for biodiversity if they are connected to ecological corridors and well managed (no use of pesticides, late mowing, etc.).
- Quarries, construction sites or landfills, which significantly transform the environment but which, as they are often "renatured" as they are exploited, constitute a reversible artificialization.
- Surfaced or built-up areas, i.e. housing, business parks, roads or car parks, which are of almost no interest for biodiversity.
Artificialization of soils in Île-de-France
Land use changes in Île-de-France: area and annual number of hectares changing between 1999 and 2012
Taxation of artificialisation: 4 lessons learned
Assuming that the dynamics of artificialisation at the national level are not radically different from those in Île-de-France, we can draw many lessons from this figure, useful for the current reflection on the taxation of artificialisation. Four of them are highlighted here.
The first is that the majority - 60 % in Île-de-France - of the new artificial spaces are built or paved spaces, in other words "concrete". Housing construction has a major responsibility in this concreting: 23 % of the spaces are artificialized to build individual dwellings, and 3 % for collective dwellings... which provide more or less the same number of dwellings. 5 % are roads and other transport infrastructures and 6 % are car parks.
Nothing surprising so far. What is more surprising is that 19 % of the artificial land is being created by zones of economic activity, including logistics warehouses, and that these activities are progressing very strongly.
The second lesson is that artificial open spaces are victims of this concreting in proportions equivalent to agricultural land. These spaces, like green spaces, are built over time in a dynamic of urban densification which is certainly desirable to limit the consumption of space, but which also contributes to the loss of ecosystems.
Thirdly, artificialisation is not, by far, only a "progression of concrete": 22 % of the new artificial spaces are transformed into open artificial spaces (sports fields, artificial lawns, etc).
Fourthly, while it is indeed cultivated land that is the first to be affected by artificialisation, it can be misleading to focus solely on preserving the potential for cultivation. Natural open spaces, which include rare environments, are also victims of artificialisation, and can also be transformed into intensive agricultural land, with important consequences for biodiversity.
A detailed analysis of land conversion dynamics in a region such as Île-de-France thus highlights that artificialisation is not limited to the concreting of agricultural land for housing construction.
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What tax against artificialisation?
If the objective of the future tax is to weigh on the uses most strongly responsible for artificialisation, then it will also have to target the development of areas of economic activity, the construction of new artificial open spaces, their progressive concreting, or the progression of agricultural land over natural areas.
A tax that is intended to be an incentive requires a fine definition of the types of artificialisation targeted, a thorough understanding of their economic logic and constraints, and must be accompanied by a modification of existing regulatory and fiscal mechanisms, some of which encourage artificialisation.
If, on the contrary, the objective of the tax is to generate funds to compensate for the negative effects of developments that artificialise the territory, then a broad base with a low rate will be preferred. And it will be the modalities of these compensations and corrective actions that will make the success or failure of this tax.
Damien Demailly, Coordinator of the IDDRI New Prosperity Program, Yann Laurans, Biodiversity Programme Director IDDRI – Alice Colsaet – IDDRI
Original of the article published on the Iddri Blog, October 30, 2017
1] the MOS, carried out by the Institut d'aménagement et d'urbanisme d'Île-de-France (Paris Region Institute for Urban Planning and Development)
2] "For an approach to soil artificialisation from the point of view of biodiversity - the case of Île-de-France" -IB N°01/2017)
