Oil refineries and drilling platforms in the U.S. are vulnerable to rising sea levels and more powerful storm surges. Fuel pipelines, barges, railways and storage tanks may sustain more damage due to melting permafrost and severe weather. Warming seas and water shortages put nuclear and other electric power plants at risk. Power lines can be blown away by hurricanes and other extreme weather events.
In other words, all of the infrastructure Americans rely on to heat their homes, power their lights and fuel their trains, trucks and cars is increasingly exposed to risk of failure in a changing climate.
That may seem clear to any one of the 1.1 million people who lost power in the New York area during and after Hurricane Sandy, but those are also the formal conclusions of a U.S Government Accountability Office (GAO) report released in January and just made public.
The report summarizes much of the research published in recent years about the vulnerability of U.S. energy infrastructure to a changing climate. It is a response to a request from members of Congress for details about risks posed by global warming, how infrastructure can be adapted to withstand the ravages of a changing climate, and what role the federal government plays in helping make the adaptation happen.
The GAO report shows that climate change is a practical concern for U.S. energy producers and operators of energy transmission and distribution lines, said Klaus Jacob, a seismologist at Columbia’s Lamont-Doherty Earth Observatory and an expert in climate change adaptation. Jacob is unaffiliated with the GAO and was not involved in the creation of the report.
Multiple outcomes of climate change are likely to work together to threaten U.S. energy infrastructure, the GAO reported. Increased air and water temperatures could wreak havoc on the U.S. electricity sector, reducing the water available for cooling electric power generators and imperiling electricity supply while increasing consumers’ demand for electricity, the GAO said.
Sea level rise, along with more extreme weather and coastal erosion, threatens infrastructure in low-lying areas, while warmer temperatures and drought increase flooding risk and wildfires, eventually limiting the amount of electricity that can be generated and transmitted during periods of high demand.
Because the report focuses on the financial risks posed by taking no action in the face of climate change, government officials may take the report more seriously than if it were only making an environmental argument for taking action, Jacob said.
The GAO report does not question scientific findings on global warming, and it shows that many energy companies recognize the risk they face from climate change, said Steven Weissman, director of the Energy Program at the Center for Law, Energy and the Environment at the UC-Berkeley School of Law.
"This nonpartisan report should shift the burden of proof for any firms or agencies that are dragging their feet," Weissman said, adding that the report could focus the attention of the public and policymakers on the need to strengthen all public infrastructure to better stand up to climate change.
Jacob said the GAO's report may help accelerate the U.S. Nuclear Regulatory Commission’s assessments of aging nuclear power plants in the U.S., highlight the importance of setting higher standards for those plants, and encourage the federal government to appropriate more money for the research and development of new renewable energy production and storage technologies.
He criticized the report for underestimating sea level rise, however. The report says that the sea level rise is occurring faster than at any time in the last 2,000 years, and that “sea levels are projected to continue to rise, but the extent is not well understood.”
Sea levels have risen globally by roughly 8 inches since the beginning of the 20th century, and a new study published in February in the Proceedings of the National Academy of Sciences projects that sea levels could rise between 9 inches and 48 inches by 2100, depending on the melting rate of the Antarctic and Greenland ice sheets.
The 8 inches of sea level rise over the past 114 years is already enough to have made storm surges more powerful, put pressure on infrastructure in places like South Florida, and exposed millions living along the coast to additional flooding. Three more feet of expected sea level rise over the remainder of the century will make these problems exponentially worse, threatening electric power plants already at risk from water shortages and higher temperatures, the GAO concluded.
Both coal and nuclear power plants require a significant amount of water to generate, cool and condense steam. In 2007, a drought in the southeastern U.S. forced some power plants to shut down or reduce power production because water levels in lakes, rivers and reservoirs nearby dropped below the intake valves supplying cooling water to those plants, according to the report.
The Browns Ferry Nuclear Power Plant in Alabama had to reduce its power output three times between 2007 and 2011 because the temperature of the nearby Tennessee River was too high to receive the plant’s discharge water. The opposite situation occurred in 2012 when the Millstone Nuclear Station in Connecticut shut down one reactor when water from Long Island Sound was too warm to be used for cooling the plant, according to the report.
“Higher temperature of intake cooling water does not pose an additional risk if proper operational procedures are followed, but it means that the efficiency of nuclear power production is reduced, and that when that happens, there will be additional need for power produced largely by fossil fuel, which in turn accelerates climate change,” Jacob said.
The report emphasizes that sea level rise and extreme weather are just as much of a threat to electric power plants, which often exist in low-lying areas and along coastlines.
Hurricane Sandy forced several Northeast coastal nuclear power plants to shut down, and a 2013 Stanford University paper identified three coastal nuclear power plants in the path of the storm as among the nation’s most vulnerable nuclear power plants to storm surge.
Renewables are also vulnerable to climate change, the GAO said.
Hydropower is possibly the renewable energy source most vulnerable to climate change because rising temperatures lead to increased evaporation, which in turn can reduce the amount of water available for hydropower and degrade fish and wildlife habitat. For example, a 1 percent decrease in precipitation leads to a 3 percent drop in hydropower generation in the Colorado River Basin, the GAO reported. Climate change is expected to make precipitation events come in heavier bursts, while simultaneously increasing the length of dry spells in many regions.
High temperatures and poor air quality from regional haze, humidity and dust in the air can reduce the energy output of utility-scale photovoltaic (solar) power plants, while concentrated solar plants that don’t use photovoltaic cells are susceptible to drought because they require water for cooling, the report said.
The GAO said energy and power companies are taking measures to shore up, or "harden" (that is, to make the infrastructure more resistant to extreme weather) their equipment, lines and infrastructure so they can withstand high winds, more significant storm surges, and other challenges posed by climate change.
Such measures are expected to be implemented in New York state as power companies there plan for power line and equipment improvements. The expectation was outlined in a Feb. 20 settlement between the New York Public Service Commission and Consolidated Edison, the New York City-area’s largest utility, requiring ConEd to study how climate change will affect its systems and find ways to mitigate those effects.
“We have performed extensive analysis of our system and the impact of climate patterns and believe our proposals are a significant step toward protecting critical equipment and customers from major storms," ConEd spokesperson Allan Drury said Friday via email when asked about the GAO report. "We plan to spend $1 billion on storm hardening and resiliency measures over four years to protect our electric, gas and steam systems, and in fact have already put many protections in place. With the impacts of climate change, including sea level rise, temperature increase, and violent storms becoming more frequent, we expect our storm-hardening and resiliency program to evolve for many years.”
The GAO concluded that the federal government’s role in adapting the nation’s energy infrastructure to withstand climate change is limited, but it said the government can support the private sector in its adaptation measures through regulatory oversight, technology research and development and providing information about the climate.