Analyzing urban metabolism in Beijing

Longstanding buildings, infrastructure, and durable goods can have positive functional and environmental impacts on a city and its residents. However, much is still unknown about these benefits. The overall lifecycle metabolic processes are complicated, and many previous studies focused only on a specific material or product rather than the larger overall effect.

In a study published in the Journal of Cleaner Production, Brian Fath, a senior IIASA researcher and scientific coordinator of the Young Scientists Summer Program (YSSP) and his coauthors, which includes former YSSP participant FU Chenling, utilized an innovative multi-level material stock-flow network model. This more comprehensive approach yielded insights into Beijing’s material inputs and outputs of each urban sector, cumulative flows of materials and products, and waste sources for end-of-life products.

The researchers found that Beijing's main sector shifted from manufacturing to construction in the previous two decades. They also discovered that Beijing's resource demand and waste discharge from vehicles and railways increased greatly over the same period. Furthermore, the study shows that while strides have been made in recycling, Beijing must do more to meet its waste generation goals.

"Tracking the whole life cycle process from raw material extraction to processing and manufacturing to in-use and final discharge driven by the accumulation of physical capital (buildings, infrastructure, and  durable goods), can clarify how many resources are consumed and which products generate the environmental impacts,” explains Fath. “Knowledge of these metabolic flows can help policymakers to trace back to the source."

by Jeremy Summers