Water–Energy–Carbon Nexus of Social Water Cycle System and Low-Carbon Regulation Strategy

Abstract

Water is the most active and critical factor in the socio-economic system, and the scale of greenhouse gas emissions accompanying water withdrawal and treatment is increasing. It is important to study the energy consumption and carbon emission of the social water cycle system to promote the achievement of carbon peaking and carbon neutrality. This study summarizes the current status of energy consumption and carbon emissions in the social water cycle from the perspective of water ‒ energy‒ carbon nexus. Based on the analysis of change trends and influencing factors and focusing on existing problems and challenges, it proposes strategies for the efficient and low-carbon development of the social water cycle system under the carbon peaking and carbon neutrality targets. China’s social water cycle system is developing toward an energy-intensive direction. The carbon emission intensity in water supply and drainage sectors increased the most, with an increase of 23.3% and 78.6% respectively from 2009—2021. With the increase of the scale of unconventional water and inter-basin water transfer, the energy consumption and carbon emission of the water system will continue to increase in the future, and the challenge of carbon neutrality is daunting. The study recommends that (1) basic scientific research should be strengthened and a carbon accounting system should be built for the whole process of social water cycle, (2) the research and development of system configuration and low-carbon technologies should be promoted to improve the comprehensive capabilities for pollution and carbon reduction as a whole, (3) energy conservation should be promoted in the whole society to realize the dual conservation of water and energy, and (4) carbon emission management in the water system should be improved to realize the low-carbon development of the social water cycle.

Keywords

• carbon peaking and carbon neutrality
• social water cycle
• water–energy–carbon nexus
• carbon accounting
• water management