Net-Zero Embodied Carbon in Buildings with Today's Available Technologies.

Area of Science:

• Environmental Science
• Sustainable Architecture
• Climate Change Mitigation

Background:

• Building construction is a major source of greenhouse gas emissions, contributing significantly to the climate crisis.
• Current strategies for decarbonizing the construction sector are insufficient, necessitating innovative approaches.

Purpose of the Study:

• To assess the feasibility of achieving net-zero embodied carbon in Japan's building sector by 2050.
• To identify key technologies and strategies for reducing carbon emissions in building construction.

Main Methods:

• Utilized a systems analysis approach to model emissions reductions across Japan's building sector.
• Evaluated the impact of various technologies including decarbonized electricity, low-carbon materials (steel, concrete), increased timber construction, optimized design, and extended building lifespan.
• Assessed the potential for enhanced forest carbon uptake through expanded domestic timber supply and reforestation.

Main Results:

• Net-zero embodied carbon in buildings is achievable in Japan by 2050 using existing technologies.
• Increased use of timber structures offers the largest emissions savings, potentially reaching ~35% annually by 2050.
• Responsible reforestation and a forest-city carbon cycle can increase forest carbon uptake by ~60% without expanding forest area.

Conclusions:

• Decarbonizing building construction relies on the strategic implementation of existing technologies and design principles, not future innovations.
• A circular economy approach integrating forest resources and urban development can significantly contribute to climate change mitigation.
• The study provides a roadmap for achieving sustainable building practices and reducing the environmental impact of the construction industry.