The idea of sustainable development naturally emerged later than the need for it. It is only when intergenerational solidarity is no longer assured that we become concerned about it.
According to the definition given in the 1987 Brundtland Report (UN), sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It is surprising that debt and its increase are rarely associated with this concern. The transmission of heritage is also forgotten.
There is a fear in this definition, which is not even hidden, of the consequences of the economic development of the 20th century. Our era is characterized by the contradiction between the pursuit of growth and the limitation of resources.
"Green" capitalism sees an opportunity in the crisis of limits. However, it is unlikely that engineering will be able to remedy the ills it has caused.
It seems that growth is over. It was easier to make adjustments in times of inflation.
We are reduced to finding our way in the peasant economy, in the capitalization of knowledge and reserves, in the conservation of what can still be saved. The "left" did not survive this.
The very idea of sustainable development is dubious: it assumes the sustainability of growth. Established with the ecological crisis due to negative externalities, it proposes a variation of capitalism that pushes the limits. It is therefore an evolution of growth supposed to reassure environmentalists. It is the energy transition that is supposed to address climate change (among other things).
Sustainable development considers a collection of themes: energy, insulation, agriculture, transport... to improve each one without affecting the whole. The result is to perpetuate the imbalance between three domains: economic, social, and ecological.
The overall cost, for example, is an attempt to anticipate all the future costs of an investment. It allows not only for the installation but also for maintenance and use. Its main interest is to make the uncertainty of choices felt. Another approach, equally economic, is the life cycle analysis of products. Thus, one can account for the gray energy required for manufacturing in a more complete balance sheet.
The limits of resources have become sensitive and contradict the ideologies stemming from the French Revolution. Some catastrophes, increasingly close, remind us of the fragility of this rational edifice.
After some unforgettable accidents, the precautionary principle must address health concerns. It is first applied to recognized harmfulness. This is why lobbies will defend glyphosate, hydraulic fracturing of bituminous rocks, electromagnetic radiation from modern devices, or volatile organic compounds from cleaning products, as they have defended tobacco or asbestos by funding controversial "studies" in order to complicate the issues. Thus, the precautionary principle requires a control authority, whose independence can be questioned.
Urban planning, because it is a long-term discipline, is directly interested in the idea of sustainable development.
The city of sustainable development refers to proximity. The density trend is questionable : it does not necessarily meet the needs of good transport links or access to nature...
Finally, this paradoxical notion raises the question of means: correcting the defects resulting from a global choice perpetuates it without challenging it. This is the whole question of reforms.