Emissions from the production of materials like metals, minerals, woods and plastics more than doubled in 1995 - 2015, accounting for almost 25% of all greenhouse gas (GHG) emissions worldwide. This is equivalent to the total GHG emissions from agriculture, forestry, and land use change combined. Yet, material efficiency receives far less attention in climate discussions.
The International Resource Panel (IRP) Report, Resource Efficiency and Climate Change: Material Efficiency Strategies for a Low-Carbon Future – to be released on 18 November 2020 at the Race to Zero event - is the first comprehensive scientific analysis of potential GHG emission savings from material efficiency. For this, it zooms into two carbon-intensive sectors: residential buildings and passenger vehicles.
80% of emissions from the production of materials are linked to the construction and manufacturing sectors, in particularly our homes and cars.
Applying material efficiency strategies can reduce GHG emissions from the life-cycle of construction, operation, and deconstruction of homes by an average of 40% in seven major developed countries - Canada, France, Germany, Italy, Japan, the United Kingdom and the United States (G7 countries) and by 70% in China and India. It can also reduce GHG emissions from the manufacturing, operations and end-of-life management of cars by 40% in the G7 and by 35% in China and India.
According to the total carbon budget proposed by the IPCC, the G7 would need to limit their remaining CO2 emissions to 50 gigatons for temperature increases to stay at 1.5°C. The IRP estimates that 23 gigatons of emissions could be saved in the G7 through material efficiency strategies in 2016-2060.
The IRP finds that the most promising strategy comes from the consumption side – more intensive use.
For cars, this means ride-sharing, car-sharing and a shift towards smaller vehicle sizes. If one in four journeys in the G7, China or India was a shared ride, then the carbon footprint of the use and production of cars would decline by as much as 20%.
For homes, more intensive use means increasing use rates through, for example, peer-lodging, or smaller and more efficiently designed homes. IRP modelling shows that reducing demand for floor space by up to 20% could lower GHG emissions from the production of materials by up to 73% in 2050.
Other material efficiency strategies to be considered include the recycling of building materials, less material by design in both cars and homes, and the use of alternative low-carbon materials (for example, sustainably sourced wood instead of reinforced concrete in homes).
“Climate mitigation efforts have traditionally focused on enhancing energy efficiency and accelerating the transition to renewables. While this is still key, this report shows that material efficiency can also deliver big gains,” said Inger Andersen, UNEP’s Executive Director.
The cuts revealed by the report are on top of emission savings generated by the decarbonization of electricity supply, the electrification of home energy use, and the shift towards electric and hybrid vehicles. If the world focuses on energy efficiency without boosting material efficiency, it will be almost impossible and substantially more expensive to meet the Paris climate targets, the report warns.
Many of these emission reductions will only be possible if countries create enabling policy environments and incentives. Policies that apply across sectors may have a greater impact than those targeting a single sector. These include building certification, green public procurement, virgin material taxes, and removal of virgin material subsidies.
The IRP urges policymakers to consider resource efficiency and materials in the next generation of their Nationally Determined Contributions (NDCs), broadening the scope of targets and increasing the magnitude of the intended mitigation ambition. Some countries have started doing this, as presented in the Resource Efficiency and Climate report:
- China’s NDC specifically mentions a commitment to the efficient use of materials. It includes measures aimed at, among others, improving the efficiency and lifespan of existing and new buildings and promoting recycled construction materials.
- Japan’s NDC includes a commitment to use blended cement
- India’s NDC refers to recycling, “enhanced resources efficiency and pollution control” (in addition to energy efficiency) and the general need to “use natural resources wisely”