Sustainability is a critical issue for the world, and reducing greenhouse gas (GHG) emissions is a key part of achieving it. Sustainable options like demand management, materials efficiency, and circular material flows are essential to reduce GHG emissions. However, these options are not considered in global scenarios nor national economy-wide scenarios due to their relative newness, and bottom-up industry-specific models are preferred.
For basic materials like primary metals, building materials, and chemicals, low-to-zero GHG intensity production processes are at the pilot stage. These processes can increase production costs, but cost increases for consumers can be minimized. Additionally, increased plastics recycling can change the location of GHG-intensive industries and the organization of value chains. Regions with abundant low GHG energy and feedstocks can export hydrogen-based chemicals and materials.
Transparent GHG accounting and standards, demand management, materials and energy efficiency policies, and R&D for low emission materials and products are crucial. High electrification and improved energy and material efficiency can reduce GHG emissions within and outside a city's administrative boundaries. Implementation of city-scale mitigation strategies can create effects across sectors.
Existing and new buildings will reach net zero in 2050 if there is sufficient efficiency and renewable energy measures while barriers to decarbonization are removed. However, there is potential for lock-in in buildings, with low renovation rates and low ambition of retrofitted buildings. The transport sector also requires demand-side options and low-GHG emissions technologies. Investments in supporting infrastructure for electric vehicles are necessary.
Conservation, improved management, and restoration of forests and other ecosystems are also important to reduce GHG emissions. Demand-side mitigation, changes in infrastructure use, end-use technology adoption, and socio-cultural and behavioral change are all essential components of reducing GHG emissions.
In conclusion, achieving sustainability requires a range of measures to reduce GHG emissions. Demand management, materials efficiency, and circular material flows are essential, but they require bottom-up industry-specific models. Additionally, transparent GHG accounting and standards, city-scale mitigation strategies, and investments in supporting infrastructure are crucial. Achieving sustainability requires a collective effort from policymakers, industries, and individuals.
Climate Change 2022: Impacts, Adaptation, Vulnerability: Summary for Policymakers - IPCC
