Bio-based building materials and temporary carbon storage

Global warming has become an indisputable phenomenon, thanks to precise temperature measurements taken on the surface of the globe and to numerous scientific studies, notably compiled by the experts of the IPCC* (Intergovernmental Panel on Climate Change) since 1988. Awareness of global warming on the part of public authorities led to the first international conference in Rio in 1992, followed by annual meetings, the COPs (Conference Of the Parties) since 1995, to reflect on and commit countries to limiting the average temperature of the earth's surface. COP3 in Kyoto (1997) led to the "Kyoto Protocol", signed and ratified by over 190 states, including all European countries. COP21 in Paris in 2016 led to new commitments on limiting global warming (the Paris agreements).

In Europe, the building sector accounts for a significant proportion of man-made greenhouse gas (GHG*) emissions: between 40% and 45% according to studies . These GHGs are linked both to the construction of buildings (extraction of raw materials, transport, processing, on-site implementation, maintenance, end-of-life) and to the use of buildings (heating, lighting, cooling, ventilation, domestic hot water, household appliances). Currently, use accounts for around three quarters of emissions, and construction for a quarter . This is why, since the 1990s, public authorities have mainly focused their regulations on controlling energy use, via thermal regulations. The aim is to build positive-energy buildings by 2020, i.e. passive buildings equipped with energy production systems. Achieving this goal means increasing the amount of insulating materials in building envelopes. The reduction in energy use, coupled with an increase in the quantity of materials in the walls, is logically focusing more and more attention on materials, their energy content and their environmental impact. In France, this is the subject of the E+C experiment– (Bâtiments à Énergie Positive et Réduction Carbone), which began in November 2016.

Building materials are often seen as "GHG emitters", in the same way as cementitious materials and steel products. For these sectors, the ecological effort consists in limiting the production of GHGs linked to their products: process optimization, alternative fuel chains, use of renewable energies, circular economy, low environmental impact raw materials chains.

Bio-sourced*...