Fourth NCA Addresses U.S. Economic Effects, Energy Infrastructure, Adaptation

Published On
Nov 28, 2018

A new federal report released on Black Friday warns U.S. energy infrastructure is ill-prepared for the anticipated environmental and economic implications of climate change. According to the National Climate Assessment (NCA), in some sectors, climate change may result in annual economic losses of hundreds of billions of dollars by the end of the century.

The NCA states the United States will be "increasingly threatened by more frequent and longer-lasting power outages affecting critical energy infrastructure and creating fuel availability and demand imbalances." Considering the importance of energy in the U.S. economy, the potential for "cascading impacts" means actual economic implications may be difficult to predict. The report, however, zeroes in on specific areas of concern.

The energy sector is particularly susceptible to the effects of extreme weather, including high temperatures, more powerful storms, increased flooding and more severe droughts, which will mean greater damage to infrastructure. In the Southeast, for example, the report estimates sea level rise could expose 69 power plants to storm surges from a Category 1 hurricane. In the event of a Category 5 hurricane, that number jumps to 291. In addition, the report states sea level rise could expose dozens of power plants to 100-year floods.

"This would put an additional cumulative total of 25 gigawatts (GW) of operating or proposed power capacities at risk," the report states.

The report breaks out different scenarios as Representative Concentration Pathways (RCPs). These estimates of the effects on power plants are based on the RCP the report considers the "low-end," meaning even with emissions reductions, these outcomes are likely.

On the opposite end of the water-level spectrum, droughts could harm the productivity of power plants, too. According to the NCA, most U.S. power plants rely on a steady supply of water for cooling. If water availability decreases or water temperatures increase, productivity could be threatened.

"In North America, the output potential of power plants cooled by river water could fall by 7.3% and 13.1% by 2050," the report states.

Of course, less water means less hydroelectric power, an emission-free energy source the United States relies upon for about 7 percent of its electricity generation.

"A changing climate also threatens hydropower production, especially in western snow-dominated watersheds, where declining mountain snowpack affects river levels," the report states.

Meanwhile, the NCA anticipates net electricity demand to continue to increase.

The U.S. energy sector is undergoing an evolution driven by declining costs of renewable sources, markets that are increasingly favorable to alternative energies, and governmental policies. With coal on the decline and sources such as solar and wind on the rise, the United States is making progress in emissions reductions. It remains unclear, however, how much of an effect these changes will have.

For its part, the NCA credits diversification of energy generation as a positive in the future of U.S. energy generation. Furthermore, the report states energy efficiency efforts have been "remarkably successful."

Challenges remain with rising energy demands and aging infrastructure. The report addresses the fact that U.S. energy infrastructure is not prepared to sustain worsening conditions.

"[Seventy percent] of the grid's transmission lines and power transformers are over 25 years old, and the average age of power plants is over 30 years old," the report states. "The components of the energy system are of widely varying ages and conditions and were not engineered to serve under the extreme weather conditions projected for this century."

With regard to energy, the NCA concludes more efforts need to be taken to improve energy system resilience. In addition, recent storms, such as Superstorm Sandy in 2012 and Hurricanes Harvey, Irma, and Maria in 2017, enabled authorities to rebuild in more resilient ways, updating damaged infrastructure with more modern solutions. The NCA suggests some hope in U.S. adaptability even in the face of substantial economic and environmental costs.

"For the electric grid, improved modeling and analysis of changing generation resources, electricity demand, and usage patterns are helping industry, utilities, and other stakeholders plan for future changes, such as the role of increased storage, demand response, smart grid technologies, energy efficiency, and distributed generation including solar and fuel cells," the report states.

Electrical contractors, as it turns out, will play a primary role in U.S. infrastructure development and resilience in response to climate change. The report does conclude, however, that "the current pace, scale, and scope of efforts to improve energy system resilience are likely to be insufficient to fully meet the challenges presented by a changing climate and energy sector."

The NCA is produced by the U.S. Global Change Research Program (USGCRP), which the Global Change Research Act of 1990 mandates must deliver the NCA to the president and Congress no less than every four years. The USGCRP released the fourth NCA in two volumes, the first published in 2017. Whereas the first volume of the fourth NCA addressed the science of climate change, volume two addresses the economic and human welfare impacts of climate change. It is a product of 300 federal and non-federal experts who wrote this assessment based on "peer-reviewed scientific literature, complemented by other sources (such as gray literature) where appropriate."

The report offers a comprehensive assessment of many topics beyond energy, including transportation, agriculture, water, human health and international effects. It also breaks out forecasts by U.S. regions. To read more, visit

About the Author

Timothy Johnson


Timothy Johnson is the former digital editor for ELECTRICAL CONTRACTOR magazine.

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