The subsurface as a common good: a research programme for the responsible and sustainable use and exploitation of the subsurface

The subsurface (between ~1m and ~5 km below the surface) is an area of interaction between solid Earth and human activities. It is a physical environment hosting many human infrastructures and that is essential to meeting the challenges of sustainable development.

Key issues associated with the subsoil

Current energy transition models point to a growing need to exploit new mineral resources, particularly for the energy and transport sectors. They also point to the need to develop new low-carbon energy sources, such as deep geothermal, to generate heat and power. One of the solutions to the ongoing climate change is to start storing CO₂underground. Finally, there is an increasing need to make better use of urban space by incorporating the subsurface.

Research questions

To better address the challenges of sustainable development, we need to better plan and manage access to the subsurface against a backdrop of growing demand. To this end, it will be necessary to:

• better model future national demand and scenarios for different subsurface resources and uses;
• improve knowledge of subsurface potential;
• develop new exploratory and exploitation technologies;
• better integrate environmental constraints;
• take better account of social and economic issues;
• improve governance and legal tools.

3 research goals and 8 platforms

To this end, the Subsurface PEPR is designed to create national momentum around research on the subsurface. It is structured around three research goals and eight platforms:

• The first goal is to quantify national demand for subsurface resources/uses for different scenarios relating to energy consumption and the energy mix, GDP, and urbanisation levels. It will include the following platforms:
  • Building scenarios for use of the French subsurface
  • Dynamic modelling of changing energy and economic resources
  • Prospective technical and economic studies
• The second goal is to better characterise the geological potential needed to meet demand, as well as to help develop new technologies. It will include the following platforms:
  • Digital Earth
  • Innovative and sustainable technologies for using the subsurface
• The third goal focuses on the environmental, social and legal possibilities of implementing – or not – the exploitation and use of the subsurface. This will include the following platforms:
  • Environmental assessment and life cycle studies
  • Towards human sciences and the politicisation of the surface
  • Regulations

5 categories of subsurface resources/uses

The PEPR targets five categories of subsurface resources/uses:

• mineral resources;
• deep geothermal;
• storage of CO₂, hydrogen and methane;
• native hydrogen;
• urban infrastructure.

5 worksites

The PEPR is targeting five worksites associated with specific types of subsurface resources and uses:

• the Massif Central (mineral and geothermal potential);
• the Rhine Graben (deep geothermal potential);
• the Aquitaine Basin (subsurface storage, emerging georesources and energy uses);
• the centre of the Paris Basin (reflecting most of the socio-economic challenges in terms of urban subsurface management);
• French Guiana (combining an extraordinary but fragile ecosystem with a rich and little-known subsurface).