By Caleigh Wells for KCRW.
Broadcast version by Suzanne Potter for California News Service reporting for the Solutions Journalism Network-Public News Service Collaboration


Many Angelenos have noticed a major difference in the county's air over the past few years. It's hotter, more humid, less toxic. And Southern California's marine layer is shrinking. But how much?

It's hotter than it used to be.

Of course, it's hotter almost everywhere. Heightened greenhouse gas emissions have warmed the planet by about 1.4 degrees Fahrenheit. But LA is warming faster than most places, averaging more than 4 degrees Fahrenheit higher than it was in the 19th century.
We're heating up more than almost anywhere else in the country.
That's thanks to the urban heat island effect.
Compared with rural areas, cities have more black asphalt, more buildings, more car exhaust, and less tree canopy. That makes cities better at soaking in heat from the sun.
Los Angeles is especially prone to this problem because of its notorious urban sprawl. "If we just keep replacing more and more open space with impervious stuff, we're going to keep increasing the geographic extent of anything that could contribute to the heat island," says UCLA Urban Planning and Geography Professor Kelly Tuskin.
The problem is greatest in parts of Southern California that have seen more development, such as Santa Clarita, which over the past 50 years has transformed from a rural community into the third-largest city in LA County.

It's more humid than it used to be.

The air is wetter too, which means the heat index has increased even more. That difference is heightened in Los Angeles, which was a traditionally drier climate.
"Over the past 25 years in LA, the temperature increase was about ... half a degree [Celsius]. But if you include that humidity effect, it is more like ... 2 degrees," says UCSD Meteorologist Guang Zhang.
That converts to about a 1 degree Fahrenheit rise in temperature that actually feels more like a 4 degree rise - just since the mid-90s.

Rising temperatures contribute to rising humidity. As the ocean gets warmer, it evaporates more. And as the air gets warmer, it's able to hold more moisture.

That's especially bad news for night time temperatures, which have continued to increase as well, eliminating some of the overnight relief Angelenos rely on during heat waves.
The marine layer is disappearing.
June gloom might be the bane of beachgoers, it also serves as California's natural air conditioner.
But since the 1970s, about half of the marine layer

"Summertime clouds in Los Angeles have been rising -- that is, the base of the cloud is getting further away from the ground. But the tops of the clouds aren't rising. And that means the clouds are getting thinner and they're burning off earlier in the day," says UCLA Geography Professor Park Williams.
Williams' research
has found that the average day in Santa Monica 50 years ago saw about four hours of marine fog. Today, it's more like two hours. And even just two hours per day of direct sunlight has made a noticeable difference in our temperature.
"In a place like Santa Monica, where we've cut the ... number of cloudy hours per day almost in half," he explained, "this has caused about a 2-degree Fahrenheit warming."

The air is cleaner.

Not every change to LA's air has been bad. There is less air pollution than there used to be. A lot less.
South Coast Air Quality Management District says ozone levels are at less than half of what they were in the 1950s.

USC Professor of Clinical Preventive Medicine Ed Avol has been studying air pollution's effects on children for three decades, and experiencing them firsthand for more than seven. "I remember going to school here, when it was so smoggy, some days, they wouldn't let us out to play on the playgrounds," he says. "Those days mostly are gone now. And so that really is a success story."
A lot of that success was thanks to things like mandatory catalytic converters in the 1970s that drastically reduced car emissions, and requirements from the Clean Air Act that took effect in the 1990s.
But air pollution continues to plummet today with the adoption of electric vehicles and renewable energy sources. Between 2017 and 2018, air pollution dropped 10%. In 2019, it dropped another 12%.

But after some of the worst fire years on record occurred just in the past five years, decades of progress has been undone by smoke pollution, according to new research from Stanford University. Future progress will depend on less fire and more renewable energy sources. "Kids are growing up with better respiratory health than they did 10 or 20 years ago. There is documentable evidence that things are getting better," says Avol. "But we are still in violation, under the Clean Air Act, of what the national and the state standards are set at to protect the public's health. It's not over. We're not done."

Caleigh Wells wrote this article for KCRW.


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School buses are getting cleaner in Washington state after this year's legislative session.

Lawmakers in Olympia passed House Bill 1368, which will fund the purchase of zero emission school buses.

Rep. Tana Senn, D-Mercer Island, said the program is getting off the ground quickly.

"As we work towards that long-term goal of all new school buses being zero emission, we're kick-starting this year with $40 million in grants to school districts in overburdened communities," Senn explained.

Going forward, Senn noted school districts will have to purchase zero-emission vehicles once the total cost of ownership is equal to or lower than the cost of diesel vehicles. The state is leveraging the state's Climate Commitment Act resources to fund the transition of its 10,000 school buses.

Devin Denney, director of transportation for Highline Public Schools in King County, which already has electric school buses in its fleet, said he has driven the electric buses and talked about some of their benefits from a driver's perspective.

"You're not competing against that engine noise, the kids aren't competing against the engine noise," Denney observed. "It's a much quieter bus all the way around. The major advantage, of course, is that there's no tailpipe emissions with an electric bus, so our kids' health is better protected."

Senn emphasized health studies have shown there are negative health effects from diesel vehicles for kids, and it is easy to understand why.

"If you think about kids waiting to get on their bus in front of an elementary school and you have this line of buses idling, letting out diesel fumes right at the height of a little child, it becomes obvious that this is probably not the most healthy thing for our children," Senn added.


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Today, in honor of Earth Day, climate advocates are asking California lawmakers and Gov. Gavin Newsom to rally around a plan to put a $15 billion bond measure on the November ballot.

If passed, the bond measure would fund a range of climate resiliency measures.

Sam Hodder, president and CEO of the Save the Redwoods League, said March was the tenth month in a row to break monthly heat records.

"I think Earth Day is a terrific opportunity for the broader public to recognize how nature is critical for resilience, for our quality of life, for our mental and physical health, and for our communities more broadly," Hodder outlined.

Two similar bills to put a bond measure on the ballot are under consideration in Sacramento, Assembly Bill 1567 and Senate Bill 867, but they have been stalled since last summer. The bond would finance many programs, including some to restore wetlands that guard against sea-level rise, and to remove dead wood in forests to guard against mega-fires, which Hodder noted have killed 20% of the giant sequoias in recent years.

Opponents pointed out the state already faces a budget deficit and cannot afford to take on more debt. But only 5% of California's old-growth coastal redwoods remain, mostly due to aggressive logging many decades ago.

Hodder argued the giant trees can be critical ingredients in the fight against climate change because they trap so much carbon.

"Redwood forests sequester more carbon per acre than any other forest system in the world," Hodder emphasized. "We have the opportunity to transition the redwood forest from something that is vulnerable to climate change to something that is helping to solve and address the climate crisis."

Experts blame climate change for California's wild weather over the past few years, which has been marked by extreme drought, devastating fires and flooding rain.

A new report from the National Wildlife Federation warns that the effects of climate change in the Quad Cities, along the Iowa-Illinois border, will be severe.

But researchers got the public involved in studying to find ways to head off some of the most pressing concerns.

The report says climate change means a warmer, wetter future for the Quad Cities, which straddle the Mississippi River in Iowa and Illinois.

But rather than repeat what experts have already been saying about drastic flooding along the Big Muddy, Prairie Rivers Network River Health and Resiliency Organizer Nina Struss said researchers and Quad Cities residents brainstormed solutions to tackle the effects of climate change.

"Flooding and flash flooding were the top concerns," said Struss. "Extreme heat was also a big concern, as well as drought and other extreme weather events."

Researchers combined that information with hard science at the University of Illinois to create 3D models depicting what climate-induced flooding along the Mississippi could look like in the future.

The survey also asked people to identify which geographical areas and populations are most at risk from the effects of climate change, and worked with the community on solutions to mitigate some of them.

Struss said this research proposes what are known as nature-based solutions to combat the effects of climate change - restoring, preserving and even expanding existing ecosystems, like wetlands and tree canopies. But creating more eco-friendly infrastructure, too.

"Can we work to maybe have our pavements that we're putting in be more permeable, so that they can absorb that water and have that higher water-holding capacity?" said Struss. "Can we focus on areas to plant more native plants that have stronger root systems, versus ones that have shorter root systems, to help with that water-holding capacity?"

Struss said this research isn't a one-off. It will continue to change, she said, as the climate changes, the needs become more clear, and the effects more drastic.

She said progress in addressing climate change relies on more research, education and funding.




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