LOS ANGELES — From extreme heat to floods to wildfires, Los Angeles is vulnerable to increasing climate hazards.

That’s the upshot of a new LA County Climate Vulnerability Assessment, which projects that extreme heat events will increase tenfold and wildfire events will be larger, more frequent and more destructive by mid-century.  

The assessment also predicts an increase in inland flooding with drier summers and wetter winters, as well as more frequent and severe coastal flooding events, even with small increases in sea level rise.

“The impacts of a changing climate are accelerating far faster than we had ever anticipated,” said former California Sen. Fran Pavley, who is also the current Schwarzenegger Environmental Institute director, during a webinar that presented the results from the LA County Sustainability Office assessment. “Unlike 20 years ago, when California’s first climate bill was signed to reduce emissions from vehicles, we can actually now see, feel and breathe it in LA County. We are literally in a race against time.”

Vulnerability, according to LA County Chief Sustainability Officer Gary Gero, is the nature and degree to which a system or sub population is exposed to significant variations in the climate coupled with the degree to which that system or sub population is affected and its subsequent inability to moderate potential damages or cope with the consequences.

Heat, drought, wildfire, inland flooding and coastal flooding are the main climate hazards the county is facing, so the assessment looked at each hazard using census tract data to determine a population’s vulnerabilities. Assessments were based on social factors such as age, gender, education, health, mobility and race, as well as the physical vulnerabilities of the area’s infrastructure systems such as communications, energy, transportation, water and housing.

“Once you know who or what is vulnerable to the kinds of climate impacts you’re expecting and where those impacts are likely to occur, then government and policy makers can start to design programs in response to protect our communities,” Gero said.

Extreme heat, Gero added, is one of the most significant impacts of climate change on LA County. By 2050, the assessment predicts that the number of extreme heat events in the county will increase tenfold. An extreme heat event is when temperatures reach the 98th percentile for at least four days. Those typically occur once every other year but will increase to twice a year within three decades.

The populations who are most vulnerable to extreme heat are people with pre-existing conditions, outdoor workers, children and older adults, the assessment found. Extreme heat can trigger severe asthma or heart attacks and can also decrease cognitive function, Gero said, adding that there are higher accident rates and levels of workforce absenteeism during heat waves.

The communities of Reseda and Winnetka are particularly vulnerable to extreme heat because so many of its residents have health conditions, the assessment found. Santa Clarita is also vulnerable to extreme heat due to its high proportion of older adults.

People of color are disproportionately affected. While Latinx people account for 49% of LA County’s population, they make up 67% of the population in communities with high vulnerability to extreme heat. Black Angelenos, who are much more likely to work outdoors or be unsheltered, are at greater risk of exposure to harsh environmental conditions.

“It used to be when we broke a heat record or any kind of weather-related record, it stood for 40 years,” Gero said. “Now our records stand for two to three years because we just see an acceleration of extreme heat and extreme weather.”

When it comes to coastal flooding, the assessment found the most vulnerable populations are mobile homes and low-income households. Long Beach and San Pedro are particularly vulnerable to extreme flooding from sea level rise, since many low-income homes in those areas are in flood zones.

Even so, nearly 20% of all LA County properties are projected to be at risk of flooding during a large storm event, according to California Insurance Commissioner Ricardo Lara. Every county in California has been declared a federal disaster area for flooding at least once since 1992, he said.

“Low-income communities of color have historically been pushed to the margins and will suffer disproportionately by climate impacts, including rising sea levels and flooding,” Lara said during the webinar, adding that his office is looking at ways to address the impacts of climate change at the state level.

“The reality is that housing that burns down repeatedly is not affordable. A house that repeatedly floods is not affordable. Increased health risk and extreme heat is not affordable,” he said. “Insurance is a tool to incentivize prevention and a tool for promoting full, equitable recovery. I’m committed to finding ways to make our vulnerable communities and our businesses safer from these climate-related threats.”

Already, Lara’s office is backing AB 2238, a bill introduced in the California legislature in February that would create a statewide advance warning and ranking system of extreme heat waves to help protect vulnerable communities and reduce hospitalizations. Last year, his office launched the Safer from Wildfires program that established guidelines for home and business owners to reduce their wildfire risk.

The LA County Climate Vulnerability Assessment comes two years after the Board of Supervisors unanimously adopted a sustainability plan. The board plans to use the new vulnerability assessment to spearhead actions and policies around the impacts it outlined.

“The pandemic reminded everyone that our fate is shared and that how we protect the most vulnerable and least served in our community will determine our collective resilience,” said LA County Board of Supervisors Chair Holly Mitchell. “The pandemic highlighted the severe inequities in our society that have assigned risk and vulnerability to Black, indigenous, Latinx and other people of color, as well as poor and working-class communities. These are the same communities that are impacted by climate change.”

The question is how the county will proceed from here.

“Now for the hard part: implementation,” Pavley said. “We have a lot of work to do.”