AbstractUrban areas concentrate human energy consumption within relatively small spatial footprints. Although anthropogenic heat flux (AHF) is negligible in the global radiative budget, its local concentration may create significant thermodynamic imbalances. Theoretically, these imbalances can generate buoyancy-driven convection, vertical air displacement, pressure anomalies, and microscale atmospheric instabilities. Using the First Principle of Thermodynamics and the principle of energy conservation,this article demonstrates that the energy consumed in a major city corresponds to the mechanical potential of massive hydrological flows—flows that, if physically redirected into an urban core, would create significant problems. For example, redirecting the flow of La Grande Rivière into any downtown would certainly permanently damage everything quickly. In reality, we redirect the equivalent amount of energy by using electrical wires. While heat does not damage infrastructure the way water does, the energy magnitude is identical and therefore must produce mechanical consequences in the atmosphere. This work proposes that concentrated urban heat release may interact with uneven solar heating to amplify local storms, modify boundary-layer stability, and potentially contribute to recent natural catastrophes.
Stephane Painchaud (Fri,) studied this question.