The nation's aging infrastructure makes up an interconnected web of systems that are alarmingly vulnerable to the shocks of climate change, according to a report released today that will inform the National Climate Assessment, to be made public next month.

The difficulty of strengthening the systems that support the American economy -- from electricity to drinking water -- poses significant problems requiring large investments at a time of rising risk and receding political appetite for big spending initiatives.

"It's kind of a national crisis," said Tom Wilbanks, a senior scientist at the Department of Energy's Oak Ridge National Laboratory and a co-author of the 109-page report.

It is the first time the National Climate Assessment will include a section on the risks to infrastructure, a broad term that includes most major societal investments. Among them are health care systems; the nation's web of roads, airports and seaports; and communication systems relied on by every owner of a cellphone.

The threats to these systems don't include just the physical damage they might suffer during a hurricane, a flood or a heat wave. The bigger impacts are on society, the economy and the environment, all of which depend on the smooth functioning of these systems, the report says.

"Vulnerabilities are especially large where infrastructures are subject to multiple stresses, beyond climate change alone; when they are located in areas vulnerable to extreme weather events; and if climate change is severe rather than moderate," it says.

Still, the researchers find that adaptation can significantly reduce risk. Whether lawmakers are willing to pay for it is a separate question.

'Difficult at best'
Adaptation can include efforts to reduce stormwater runoff by expanding pervious surfaces, building defensive walls to protect critical sites, strengthening building standards, and expanding "green infrastructure" that can retain floodwater.

But those changes require committed politicians and money.

"Given the political difficulties in some places around anything related to climate change, the long timeframe of the projected changes, the relative uncertainty about the exact extent of changes, and the natural tendency of most elected officials to focus on challenges likely to arise during their term of office, changing land use decisions to respond specifically to projected climate change is difficult at best," the authors say.

The report notes that research about the impacts of warming on transportation is scarce. But it cites one study about the Gulf Coast that says sea-level rise and storm surge could leave whole sections of the road network permanently underwater.

The 2008 study, finished before scientists heightened their estimates of sea-level rise, found that 2,400 miles of major roadway in the region would be submerged if oceans rise 4 feet. Additionally, 246 miles of railways, three airports and 75 percent of the area's freight facilities would be permanently underwater.

"Even greater, but temporary, impacts are expected for short term flooding due to storm surges," it says.

The report ventures into a political beehive. Overhauling the nation's deteriorating infrastructure is a tough sell, even when it's framed around problems that aren't related to climate change. That's because it's expensive, really expensive.

The report estimates that 1 meter of sea-level rise could prompt 4.6 million people in seven Florida counties to relocate. That stresses electricity infrastructure, because those people account for more than 11 percent of the area's energy demand in gigawatts. The implication is that the power systems would have to move with the people.

But before that happens, those counties could be susceptible to sweeping blackouts during hurricanes.

"About 4.6 million people live in the area where electric power damage is expected to be 100 percent," the report says. "Approximately 90 percent of outaged customers would have power restored in less than 26 days and 80 percent in less than 22 days, depending substantially on storm surge effects."

Cascading failures
President Obama placed a limited infrastructure plan at the center of his budget blueprint released Tuesday. Instead of calling for higher gasoline taxes, his plan seeks to close corporate loopholes in the tax code to fund a $302 billion transportation bill for four years. It would fix things like roads, rails and bridges.

Even if it did pass, a whole list of critical pieces of infrastructure would be left off the to-do list. They include energy systems, drinking water and sewage plants, health care operations, and industrial structures.

That's troubling to the report's authors, because if one piece of the infrastructure web is weak, the whole thing is vulnerable. They call it a "cascading" effect. In some cases, one system might escape damage during a disaster but still be useless, because it depends on a separate system, like electricity, that went down.

"Disruptions of services in one infrastructure will almost always result in disruptions in one or more other infrastructures, especially in urban systems, triggering serious cross-sectoral cascading infrastructure system failures in some locations, at least for short periods of time," the report says.

During Superstorm Sandy, about 11 billion gallons of sewage was released into waterways after treatment plants either lost power or were flooded.

The report points to several cascading events, including a heat wave that sparked 20 different failures in the span of 11 minutes, affecting millions of people in Arizona, California and Mexico.

On Sept. 9, 2011, high temperatures tripped a transmission line near Yuma, Ariz., sparking a chain of events that shut down the San Onofre nuclear power plant, caused the release of untreated sewage and required San Diego residents to boil their drinking water.

The blackout, which lasted 12 hours, disrupted emergency communications, which made it difficult to notify people that sewage had infiltrated San Diego's drinking water. Altogether, more than 7 million gallons of sewage was released from plants in Southern California and Mexico, and 7 million people lost power.

"In most cases, the questions are not which infrastructures are more vulnerable than the other but where are the points where lots of infrastructures are so connected that impacts on any one would affect a lot of others," said Wilbanks.

Choke points tend to be in urban areas, where a variety of infrastructures are clustered together and where one failure can affect a large number of people.

Temperatures aren't the only thing on the rise. Other changes unrelated to the climate stand to exacerbate the impacts of warmer and less predictable weather. The population of the United States is expected to rise from 310 million in 2010 to more than 400 million in 2050, promising to increase the number of homes that need things like power, water and roads. It also will expand impervious surfaces as precipitation is expected to increase in some areas.

"Again, the infrastructure implications are formidable," the report says.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500