Contemporary climate analogs project north-south polarization of urban water-energy nexus across US cities under warming climate

TL;DR

This study uses machine learning and climate analogs to project future water and electricity demands in 46 US cities, revealing a north-south demand polarization under climate change that could stress infrastructure and impact vulnerable populations.

Contribution

It introduces a novel approach combining climate analogs and machine learning to project city-level water-energy demand under climate change.

Findings

Many US cities may see up to 20% increase in electricity demand.

Many US cities may see up to 15% increase in water demand.

Demand increases follow a north-south gradient under high emissions scenarios.

Abstract

Despite the coupled nature of water and electricity demand, the two utilities are often managed by different entities with minimal interaction. Neglecting the water-energy demand nexus leads to to suboptimal management decisions, particularly under climate change. Here, we leverage state-of-the-art machine learning and contemporary climate analogs to project the city-level coupled water and electricity demand of 46 major U.S. cities into the future. The results show that many U.S. cities may experience an increase in electricity (water) demand of up to 20% (15%) due to climate change under a high emissions scenario, with a clear north-south gradient. In the absence of appropriate mitigation strategies, these changes will likely stress current infrastructure, limiting the effectiveness of the ongoing grid decarbonization efforts. In the event that cities are unable to match the increasing demand, there may be increased occurrence of supply shortages, leading to blackouts with disproportionate impacts on vulnerable populations. As such, reliable projections of future water and electricity demand under climate change are critical not only for preventing further exacerbation of the existing environmental injustices but also for more effective design and execution of climate change mitigation and adaptation plans.