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(dailynews.com) Even before the floodwaters receded in Houston, the role of climate change in the historic storm was avowed by scientists, reporters and politicians.

More than 50 inches of rain fell on the Gulf Coast in less than five days, resulting in more than $100 billion in damage and the deaths of dozens of people. The devastation wrought by the most powerful hurricane to hit the U.S. mainland in a decade, officials said, was exacerbated by waters warmed and expanded by climate change.

The implication: Extreme, unruly weather emboldened by a warming atmosphere could descend on unsuspecting communities around the globe.

This year’s severe monsoonal rains that simultaneously devastated regions of Africa, India, Bangladesh and Nepal, killing hundreds of people, bolstered claims of impending disaster.

So, is Southern California — also a region with a history of deadly flooding — more vulnerable now than it has been in the past?

Will the Pacific Ocean, swollen by warmed waters, erode and flood beaches and coastal communities like never before? Will heavy atmospheric rivers like the Pineapple Express deliver an unexpected wallop to vulnerable neighborhoods in the foothills of the San Gabriel Mountains?

The short answer, scientists and engineers say, is yes. The effects of a warming planet and resulting sea-level rise — whether due to human-emitted greenhouse gases or to the sun’s cycles — are already upon us and will only continue to worsen.

But, like all weather, storm impacts will vary depending on local conditions and preparations such as drainage, seawalls and emergency response systems.

County flood-control systems are being expanded to hold more water, as rainstorms are expected to deluge areas more quickly than in the past. But coastal flood-control protections across Southern California rely heavily on cash-strapped small governments to maintain and modernize infrastructure that can withstand major storms.

Problematic storms are already starting to hit the region outside the normal winter wet-weather season, which begins Oct. 15.

Some say the state’s leaders should be investing in infrastructure upgrades to protect vulnerable areas, rather than on long-term greenhouse-gas emissions reductions.

One thing is clear: A severe storm would be devastating.

“We’re not going to have a Houston event. But the number of high-level rain events are likely to increase from climate change,” said Adam Rose, a research professor at USC’s Price School of Public Policy who has studied the economic consequences of a major tsunami and extreme storm hitting the California coast.

“The loss estimates for a severe atmospheric river storm are larger than our estimates for a catastrophic earthquake,” Rose said. “It would affect so much of the state.”

A 500-year storm last hit California in 1861-62, but was much less damaging than it would be today. The subsequent population growth and business and infrastructure development have brought a litany of new dangers, from inadequate storm drain systems to ill-equipped emergency evacuation routes and personnel.

The state’s most vulnerable areas in a major winter storm are densely developed, flood-exposed cities in Los Angeles, Orange and Santa Clara counties, and much of the state’s Central Valley, according to Rose’s research.

The cost of property damage to the state in building losses, drinking water systems and other infrastructure damage if another 500-year storm hits would be more than $100 billion over five years, according to Rose’s research.

Unlike Houston, Southern California doesn’t have to worry about hurricanes. Its danger lies in seasonal cycles of wildfires and flash floods, coastal storm surges, and atmospheric rivers passing through from Mexico and Hawaii transporting periodic heavy rainstorms.

“What climate change seems to be doing to us, our models show, is delivering the same amount of rain but at a much faster pace,” said Mark Pestrella, chief engineer of Los Angeles County’s Flood Control District. “The vicious cycle is warmer air and warmer temperatures drying out the mountains, and fires burning off all plant life. So the rain erodes twice the amount if the mountains weren’t burned.”

Flood-control officials recently embarked on a project to clear sediment from the most vulnerable of the county’s 14 dams and reservoirs — Devil’s Gate in Pasadena. They’re working to remove 2.4 million cubic yards of sediment, dirt and plants using 425 trucks a day over five years to increase capacity in case of a major storm.

Orange County flood control officials are doing the same. But much of Southern California’s coastline is governed by small cities required to protect their increasingly dense, increasingly vulnerable coastal communities.

In coastal Los Angeles County, a 100-year storm (which has a 1 percent chance of occurring during any given year) would displace 50,000 people and cause $13 billion in property damage, according to a U.S. Geological Survey published in March.

“In addition to that, 600 kilometers of roads and 19 critical facilities (are threatened), including schools and water-treatment plants along the Santa Monica Bay like Hyperion” sewage-treatment plant near Dockweiler State Beach south of Playa del Rey, said Patrick Barnard, research director for the USGS’s Coastal Storm Modeling System team.

The most vulnerable areas in Los Angeles County are low-lying Malibu, Venice and Marina del Rey, which aren’t protected by the bluffs of Santa Monica and the Palos Verdes Peninsula.

In eastern Long Beach, Belmont Shore is the most susceptible to an extreme event.

The ports of Los Angeles and Long Beach pose special threats because flooding there could shut down major global business operations.

Many experts say high doses of human-generated carbon dioxide and methane gases trapping heat on the planet’s surface are the reasons oceans are warming. Others argue it as nothing to do with humans and is a result of the sun’s cycles.

In either case, the National Oceanic and Atmospheric Administration says global sea levels are rising faster than anticipated — though regions are impacted differently. The agency tracks local rising seas with an interactive online map.

The threat of melting polar glaciers is less of a concern, though some studies have found that they could deliver incredibly intense storm surges in 50 to 100 years.

Port of Los Angeles officials are working on a study due in 2019 that assesses sea-level rise vulnerabilities.

Though the port complex is considered “relatively well-fortified,” higher storm surges threaten to inundate “certain areas of the port,” said spokesman Phillip Sanfield.

New port-adjacent waterfront developments are being built at higher elevations in anticipation of higher tides and more intense surges.

Especially vulnerable communities in Orange County include Seal Beach, Sunset Beach, Huntington Beach and Newport Beach.

“They’re literally built in or on the fringes of estuaries,” Barnard said. “There is an expectation that coastal erosion and large waves are going to be getting worse. Even just 10 centimeters of sea-level rise is going to double the frequency of flooding.”

A severe, 100-year winter storm in Orange County would have triple the devastation of the same event in Los Angeles County, according to Barnard’s research.

Read more here: Here are the lessons Hurricane Harvey offers Southern California