International Industrial Ecology Day 2021

Paris climate agreement has been a major step forward to tackle the global mean temperature rise below 1.5°C above pre-industrial levels. It implies renewing most existing infrastructures and equipment by deploying a low-carbon content capital in key sectors of the economy to reach Net Zero GHG Emissions (NZE) by mid-century (buildings, transport, and power supply). However, there is a risk to overshoot such objectives due to base materials based on carbon-intensive manufacturing processes (steel, cement, etc.). Indeed, material demand is already expected to double by mid-century following economic trends. The incremental investments considered will increase furthermore material demand. The size of this surplus is unclear as most energy prospects neglect feedback between low-carbon transition and material needs. Also, the potential of future mitigation technologies to relieve the burden is still uncertain. In the meantime, most countries restrict their NZE targets to direct emissions. They do not set concrete carbon footprint targets to deal with carbon linkage. The design of stringent climate policy needs a clearer vision of the material roles in the low-carbon transition.

Our study aims to fill this gap by quantifying the link between GHG emissions and low-carbon investments through materials at a country level. We developed a national hybrid Input-Output framework designed (i) to ease the integration of various sets of expertise about low-carbon scenarios and (ii) to track the role of investment demand and material supply in the evolution of carbon footprint. We applied our method to France by comparing contrasted scenarios until 2050 (current policies, techno-push, and low energy demand scenarios). We confirmed that the material demand of carbon-intensive industries could more than offset national NZE targets and worldwide 1.5°C climate target. However, we found some options to relieve the burden considering levers of low energy demand strategies.