Quantifying Carbon Emissions Generated by Monorail Transits: A Life Cycle Assessment Approach

Area of Science:

• Environmental Science
• Civil Engineering
• Transportation Engineering

Background:

• Rail transit systems are significant sources of urban carbon emissions.
• Existing carbon quantification methods do not adequately address monorail systems.
• Carbon emissions pose a threat to city ecosystems.

Purpose of the Study:

• To propose a novel method for quantifying carbon emissions from monorail transit systems.
• To analyze carbon emissions across the entire life cycle of monorail transit.
• To identify key emission-generating processes in monorail systems.

Main Methods:

• Life Cycle Assessment (LCA) methodology applied to monorail transit.
• Division of the monorail life cycle into four stages: production, construction, use, and end-of-life.
• Case study of a monorail transit line segment in Chongqing, China.

Main Results:

• The 'use' stage accounts for the majority (93.2%) of carbon emissions.
• Steel (32%), concrete (29.6%), and cement (13.3%) production are major emission sources.
• Prestressed concrete activities represent the largest single contributor (91.1%) to emissions.

Conclusions:

• The developed LCA method provides a framework for assessing monorail transit carbon footprints.
• Targeting the 'use' stage, particularly concrete and steel production, is critical for emission reduction.
• Findings support sustainable development and the advancement of green transportation infrastructure.