“Urban Heating and Cooling Systems Underestimated in Global Energy Projections: Impact of Climate Change Could Be 50% Higher by 2099”

Existing global energy projections may be underestimating the impact of climate change on urban heating and cooling systems, according to a new study led by researchers at the University of Illinois Urbana-Champaign. The study, published in the journal Nature Climate Change, highlights the significant role that smaller-scale city-level waste heat from residential and commercial property heating and cooling systems plays in local climates and energy use.

Lead researcher Lei Zhao, a professor of civil and environmental engineering, emphasizes that the heat generated from these systems is a major contributor to the total heat generated within urban areas. This excess heat is released into the atmosphere, making cities hotter and increasing the demand for indoor cooling systems, creating a positive feedback loop that exacerbates urban warming.

The study also points out that rising temperatures due to climate change could potentially decrease energy demand during colder months, creating a negative feedback loop that could impact energy projections. However, this negative feedback loop is not enough to counteract the overall warming effect of the positive feedback loop.

To address these overlooked physical contributions to climate change, the research team used a hybrid modeling framework that combines dynamic Earth system modeling and machine learning. This approach allows them to examine global urban heating and cooling energy demand under varying urban climate change scenarios, taking into account the diverse characteristics of different cities.

Zhao stresses the importance of integrating the effects of both positive and negative physical feedback loops into energy projections to improve climate impact assessments and inform policymaking. The team is now working to incorporate additional variables and uncertainties, such as humidity, building materials, and climate-mitigating efforts, into their models to enhance energy-demand projections.

The study was supported by the National Science Foundation and the Institute for Sustainability, Energy, and Environment at the University of Illinois Urbana-Champaign. Zhao is also affiliated with the National Center for Supercomputing Applications and the Gies College of Business at Illinois.

Overall, the findings of this study underscore the need for more comprehensive energy projections that consider the complex interactions between urban infrastructure, climate change, and energy demand. By better understanding these dynamics, policymakers can make more informed decisions to support sustainable energy planning for the future.