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Swain to discuss rain in fire zone 3pm Friday, Jan. 24

Light rain is expected to dampen Southern California this weekend, easing fire conditions but also raising landslide risks in burn areas. It won't end local fire risk. The drizzle is “enough to tamp down but not end fire season,” says Daniel Swain, UC ANR climate scientist.

Join Swain for a live briefing this afternoon with updates on new fires in greater Los Angeles, the rain and snow to come, and the fire outlook in February:

YouTube Office Hours with Daniel Swain

Friday, Jan. 24, 3 p.m. Pacific/6 p.m. Eastern

https://www.youtube.com/watch?v=5KU6OP8AZO8

Join live to ask questions in the chat or watch the recording anytime at that same link. As always, these sessions are on-the-record, and media are welcome to quote from or air Swain's comments.

From Swain's Jan. 22 Office Hours:

More fire weather and risk after the rain: “I think this [rainy] period will very likely be a period of greatly reduced fire risk. Once we get back to the end of the first week in February, though, unless it rains again, we're going to be at the mercy of the winds, because all it will take is one Santa Ana event to evaporate all of this water, and we'll be right back to where we started.”

Landslide risk: “Isolated areas, particularly in the mountains, could see very intense downpours of a half an inch or an inch of rain in an hour. If that happens over a recent wildfire burn area, particularly on the Eaton or Palisades fires – or even the Line or Bridge fires from earlier in the year in September – there is going to be a risk of significant and potentially deadly debris flows. … There's very little risk from this event if you're not in or near a wildfire burn area, so this will be a net beneficial rain for 95% of people, but it could be quite dangerous for the 5% of people who live in or near those fire zones susceptible to debris flows. … If you are evacuated, there may be new evacuation orders or warnings for debris flow risk this weekend.”

UC ANR Fire Network shares resources on reducing impacts of wildfire, smoke

Fire advisors offer guidance on minimizing damage, preparing for evacuation, protecting against smoke

With exceptionally dry conditions persisting in many parts of California, residents should double their efforts to prepare homes, families, businesses and communities for potential wildfire and smoke impacts, according to University of California fire experts.

“Even as firefighters make progress in containing the Los Angeles-area fires, communities must continue to be vigilant across Southern California and other regions that are experiencing this historically dry ‘wet season,'” said Lenya Quinn-Davidson, director of UC Agriculture and Natural Resources' Fire Network.

The Fire Network is a team of UC Cooperative Extension fire and natural resource advisors, specialists and staff who deliver fire-related research, outreach, and support for communities across the state.

The experts have assembled a website with a wide range of relevant resources at ucanr.edu/fire. Quinn-Davidson said the “Wildfire Preparedness” page contains essential information on how to protect homes and property from fire: https://ucanr.edu/sites/fire/Preparedness.

“There are many small but significant tasks that people can complete to shore up potential danger spots and minimize fire damage,” she emphasized.

Experts highlight six things to do before evacuating

For communities where evacuation warnings have been issued, Quinn-Davidson and other members of the Fire Network urge residents to do six key things in advance of an actual evacuation order.

• Close windows, fireplace screens, pet doors and skylights.
• Move inside patio cushions, brooms and door mats; tie open wooden gates that attach to the house or deck to prevent a fire from traveling from the fence to the house.
• Relocate any propane tanks away from the home.
• Stage buckets of water and garden hoses in visible locations.
• Dress for evacuation: long sleeve cotton clothes, sturdy shoes, hat and face protection and leather gloves.
• Put your “go-bag” in your vehicle and share your evacuation plans with out-of-area family or friends.

The UC ANR Fire Network website also includes downloadable checklists – in English and Spanish – for your go-bag (https://ucanr.edu/sites/fire/Safety/Evacuation/Preparing_a_Go-Bag/) and for a host of important pre-evacuation tasks for your household, property, pets and livestock (https://ucanr.edu/sites/fire/Safety/Evacuation/).   

“These actions can make a tremendous difference when preparing for wildfire, even just hours before evacuation,” Quinn-Davidson said.

Take precautions to protect yourself from smoke

During wildfire events, smoke from nearby fires can blanket nearby areas. A primer on harmful health effects, a list of tips for reducing smoke exposure, and other resources and links can be found on the UC ANR Fire Network site: https://ucanr.edu/sites/fire/Safety/Air_Quality_and_Smoke/.

“It's important to monitor your local air quality so you can mitigate smoke impacts,” said Katie Low, statewide coordinator for UC ANR's Fire Network. “One go-to resource is fire.airnow.gov. If the AQI – Air Quality Index – is high, I would limit my outdoor activity, wear an N95 mask if I do go outside, and run my air purifier.”

For instructions on making a DIY air cleaner, creating a “clean air space” in your home and fitting an N95 mask properly, visit the California Air Resources Board's “Smoke Ready California” page: https://ww2.arb.ca.gov/smokereadyca.

A wildfire can also contaminate drinking water to an extent beyond what boiling can remedy; residents should check with their local water department or district for any advisories.

Another useful tool is the crowd-sourced #FireMappers fire activity map – powered by the National Alliance for Public Safety GIS Foundation, GISCorps, and CEDR Digital – accessible through the UC ANR Fire Network site: https://ucanr.edu/sites/fire/Safety/Current/. 

Media Resources

Lenya Quinn-Davidson: lquinndavidson@ucanr.edu; (707) 272-0637 

Katie Low: katlow@ucanr.edu; (530) 889-7385

UCCE offers water measurement training Jan. 30 in Davis

California water-rights holders are required by state law to measure and report the water they divert from surface streams. For people who wish to take the water measurements themselves, the University of California Cooperative Extension is offering in-person training to receive certification on Jan. 30 in Davis.

At the workshop, participants can expect to

• clarify reporting requirements for ranches.
• understand what meters are appropriate for different situations.
• learn how to determine measurement equipment accuracy.
• develop an understanding of measurement weirs.
• learn how to calculate and report volume from flow data.

The training is scheduled for 9 a.m. to 12:30 p.m. on Jan. 30 in the Valley Room at the UC Agriculture and Natural Resources Building at 2801 Second Street, Davis, CA 95616.

“We are limiting the number participants for the water measurement training to 30 people per session,” said Larry Forero, UC Cooperative Extension livestock and natural resources advisor emeritus. “If you need this training, please register soon.” 

Pre-registration is required and the fee is $35. To register, visit https://ucanr.edu/watermeasure. If you have questions, email Forero at lcforero@ucanr.edu or Sara Jaimes at sbjaimes@ucanr.edu or call (530) 224-4900.

Background:

Senate Bill 88 requires that all water right holders who have previously diverted, or intend to divert, more than 10 acre-feet per year (riparian and pre-1914 claims); or who are authorized to divert more than 10 acre-feet per year under a permit, license or registration; to measure and report the water they divert. Regulatory requirements for measurement and reporting are available on the State Water Resources Control Board Reporting and Measurement Regulation webpage. The legislation requires that installation and certification of measurement methods for diversion (or storage) greater than or equal to 100-acre feet annually be approved by an engineer/contractor/professional. 

California Cattlemen's Association worked with Assemblyman Bigelow to allow a self-certification option. Assembly Bill 589, which became law in 2018, allows any water diverter who completes this UC Cooperative Extension course on measurement devices and methods (including passage of a proficiency test) to be considered a qualified individual when installing and maintaining devices or implementing methods of measurement.

South Coast REC studies pesto profitability for small-scale basil growers

UC ANR advisors, staff research methods in conserving highly perishable product

If you visited the greenhouse at the University of California South Coast Research and Extension Center in early fall, you would have smelled a sweet aroma with notes of lemon, pepper and licorice.

In one of the conservatories, a team of UC Cooperative Extension advisors and staff grew seven varieties of basil and by the end of October, the plants stretched nearly two feet tall with leaves large enough to warrant a closer look. The wonderful smell would soon become delightful tastes, as the team planned to turn the basil into pesto.

“The rationale was to provide a high-value crop and a value-added solution for urban horticulture, transforming a highly perishable product into something that can be conserved,” said Gerardo “Gerry” Spinelli, UC Cooperative Extension production horticulture advisor for San Diego County, who initiated the passion project.

After noticing a sign at South Coast REC asking consumers to use produce grown onsite in their everyday cooking, Spinelli felt inspired. The sign also requested photos of homemade dishes be sent to South Coast REC's interim director, Lindsey Pedroncelli, to generate content for the REC's Instagram account.

Envisioning a “bigger picture” for this effort, Spinelli turned to Pedroncelli for support. The two agreed that the basil project demonstrates a viable pathway for urban growers who have limited space, and positions South Coast REC as an ideal partner for such endeavors. Uniquely located in urban Irvine, South Coast REC has nearly 200 acres of land reserved for agricultural research and is one of nine RECs housed under UC Agriculture and Natural Resources.

“Urban growers are constantly looking for new ways to grow food and market their products. Growing plants using the Kratky hydroponic system is a low-input method that is simple to establish and easy to maintain,” said Pedroncelli.

Aside from its research purposes, the project was the perfect opportunity to engage other advisors and staff at South Coast REC. The extra hands and taste buds that helped with this effort would later be known as the South Coast REC Pesto Task Force.

Growing in hydroponics

Given Spinelli and Pedroncelli's Italian ancestry, it was no question that the basil would be used to make pesto – a traditional sauce originating from Genoa, Italy that's commonly consumed on pasta. In just about two months, the following basil varieties flourished in a hydroponic system: cinnamon, Mrs. Burns' Lemon, Kapoor Tulsi, Thai Towers, Amethyst Improved, Red Rubin and the traditional Genovese. With these varieties, Spinelli and Pedroncelli were also interested in testing how taste and color affect the pesto.

Since learning about the Kratky method, a passive hydroponic technique developed by Bernard Kratky at the University of Hawai'i, Spinelli has championed it as an easy and affordable way to grow food. He has produced several videos in English and Spanish about the technique on his YouTube Channel and created a fact sheet that can be downloaded from his website.

Some of its advantages are the low initial capital investment, excellent water and nitrogen use efficiency, short cycle of production and the fact that it is modular and easy to set up, move and store – a major advantage for growers who only have access to space for a limited time and investments on immobile structures are not justifiable.

For the setup, eight 2'-by-3' tubs were used, and each was filled with 20 gallons of water before adding a fertilizer mix that contains one ounce of calcium nitrate, one ounce of magnesium sulfate or Epson salt and 0.6 ounces of lettuce formula. With the additional steps of seeding, drilling holes into the Styrofoam, and placing the net cups with seedlings into each hole, Spinelli estimated about 30 minutes of setup for each tub.

Estimating potential profit for urban growers

Although prices per quantity vary, he also estimated about $25 for the 20-gallon tub, a panel of Styrofoam and net baskets, which can all be reused. In addition, the fertilizer and propagation materials, including seeds and pellets, will cost roughly $68. When breaking these materials down according to the number of growing cycles, about one to two months each, the cost amounts to approximately $5 per tub for 25 cycles.

Using basil sold at Trader Joe's for reference, Spinelli estimated that each ounce of basil grown is worth about 70 cents. The “million-dollar question,” as Spinelli puts it, is how much profit one can earn from this endeavor. Because the Amethyst Improved and Red Rubin varieties had the lowest yields of 12 and 18 ounces, they were combined to make 40 ounces of pesto. In contrast, Genovese had the highest yield of 51 ounces of basil – which produced 64 ounces of pesto.

Using a ratio of 0.7 to 0.9 ounces of basil for every liquid ounce of pesto, and calculating projected value based on Trader Joe's pricing, the Amethyst Improved and Red Rubin combined pesto had a projected value of $21, whereas Genovese had a projected value of $36. Without being combined with any other variety, however, the smallest projected value was the Kapoor Tulsi variety which had a yield of 22.5 ounces, making 28 ounces of pesto and resulting in a $16 projected value.

There are a few costs that Spinelli and Pedroncelli could not account for, such as hypothetical transportation to the market for sale, and the various prices of ingredients used to make pesto – almonds and walnuts, for instance, could be used as a cheaper alternative to the traditional pine nuts.

“With a traditional recipe you spend $5 for the basil and $25 for the other ingredients to produce eight 8-ounce jars of pesto. If you can sell each jar for $10 at the farmers market, there are $50 for profit – maybe more if you can sell one jar for $15, or you can save with non-traditional ingredients,” Spinelli explained.

An additional advantage, which may come with additional expenses, is that pesto can be conserved. The business model could be that the grower sells basil at the farmers market and transforms the unsold product into pesto before it goes bad.

“Getting involved in agriculture can be intimidating and costly, so researching and showcasing inexpensive methods that can easily be scaled to fit your needs is incredibly helpful for both new and seasoned growers,” Pedroncelli said.

South Coast REC staff offer taste buds at ‘pesto party'

Following their harvests in October, Spinelli and Pedroncelli hosted two “pesto parties” for staff at South Coast REC. Although traditional pesto is made with Genovese basil, pine nuts, garlic, Pecorino cheese and olive oil, Spinelli and Pedroncelli experimented with different cheeses and nuts across the seven varieties of basil. Staff offered their taste buds and critical review of each pesto, advising the two chefs to add more or less of a particular ingredient.

Eager to share their progress and vision with UC ANR's senior leadership, Spinelli and Pedroncelli carefully preserved and packaged eight jars of homemade pesto and had it specially delivered to Vice President Glenda Humiston.

“This is a creative way to demonstrate innovation and a fantastic opportunity to support our urban communities. It's not just practical, but economically feasible,” said Humiston, who was pleasantly surprised by the pesto delivery. “Plus, I love pesto!” she added.

What started out as a passion project quickly turned into an opportunity to show how a resource hub like South Coast REC can empower its urban clientele both educationally and economically. It was also the perfect opportunity to engage South Coast REC staff in an activity outside of their day-to-day responsibilities, making for excellent photo ops and social media posts.

Floods, droughts, then fires: Hydroclimate whiplash is speeding up globally

New research links intensifying wet and dry swings to the atmosphere's sponge-like ability to drop and absorb water

Key takeaways Hydroclimate whiplash – rapid swings between intensely wet and dangerously dry weather – has already increased globally due to climate change, with further large increases expected as warming continues, according to a team of researchers led by UC ANR's Daniel Swain. The “expanding atmospheric sponge,” or the atmosphere's ability to evaporate, absorb and release 7% more water for every degree Celsius the planet warms, is a key driver of the whiplash. Co-management of extreme rainfall or extreme droughts, rather than approaching each in isolation, is necessary to find interventions and solutions, researchers said.

Los Angeles is burning, and accelerating hydroclimate whiplash is the key climate connection.

After years of severe drought, dozens of atmospheric rivers deluged California with record-breaking precipitation in the winter of 2022-23, burying mountain towns in snow, flooding valleys with rain and snow melt, and setting off hundreds of landslides.

Following a second extremely wet winter in southern parts of the state, resulting in abundant grass and brush, 2024 brought a record-hot summer and now a record-dry start to the 2025 rainy season, along with tinder-dry vegetation that has since burned in a series of damaging wildfires.

This is just the most recent example of the kind of “hydroclimate whiplash” – rapid swings between intensely wet and dangerously dry weather – that is increasing worldwide, according to a paper published Jan. 9 in Nature Reviews.

“The evidence shows that hydroclimate whiplash has already increased due to global warming, and further warming will bring about even larger increases,” said lead author Daniel Swain, a climate scientist with UC Agriculture and Natural Resources and UCLA. “This whiplash sequence in California has increased fire risk twofold: first, by greatly increasing the growth of flammable grass and brush in the months leading up to fire season, and then by drying it out to exceptionally high levels with the extreme dryness and warmth that followed.”

Global weather records show hydroclimate whiplash has swelled globally by 31% to 66% since the mid-20th century, the international team of climate researchers found – even more than climate models suggest should have happened. Climate change means the rate of increase is speeding up. The same potentially conservative climate models project that the whiplash will more than double if global temperatures rise 3 degrees Celsius above pre-industrial levels. The world is already poised to blast past the Paris Agreement's targeted limit of 1.5 C. The researchers synthesized hundreds of previous scientific papers for the review, layering their own analysis on top.

Anthropogenic climate change is the culprit behind the accelerating whiplash, and a key driver is the “expanding atmospheric sponge” – the growing ability of the atmosphere to evaporate, absorb and release 7% more water for every degree Celsius the planet warms, researchers said.

“The problem is that the sponge grows exponentially, like compound interest in a bank,” Swain said. “The rate of expansion increases with each fraction of a degree of warming.”

The global consequences of hydroclimate whiplash include not only floods and droughts, but the heightened danger of whipsawing between the two, including the bloom-and-burn cycle of overwatered then overdried brush, and landslides on oversaturated hillsides where recent fires removed plants with roots to knit the soil and slurp up rainfall. Every fraction of a degree of warming speeds the growing destructive power of the transitions, Swain said.

Many previous studies of climate whiplash have only considered the precipitation side of the equation, and not the growing evaporative demand. The thirstier atmosphere pulls more water out of plants and soil, exacerbating drought conditions beyond simple lack of rainfall.

“The expanding atmospheric sponge effect may offer a unifying explanation for some of the most visible, visceral impacts of climate change that recently seem to have accelerated,” Swain said. “The planet is warming at an essentially linear pace, but in the last 5 or 10 years there has been much discussion around accelerating climate impacts. This increase in hydroclimate whiplash, via the exponentially expanding atmospheric sponge, offers a potentially compelling explanation.”

That acceleration, and the anticipated increase in boom-and-bust water cycles, has important implications for water management.

“We can't look at just extreme rainfall or extreme droughts alone, because we have to safely manage these increasingly enormous influxes of water, while also preparing for progressively drier interludes,” Swain said. “That's why ‘co-management' is an important paradigm. It leads you to more holistic conclusions about which interventions and solutions are most appropriate, compared to considering drought and flood risk in isolation.” 

In many regions, traditional management designs include shunting flood waters to flow quickly into the ocean, or slower solutions like allowing rain to percolate into the water table. However, taken alone, each option leaves cities vulnerable to the other side of climate whiplash, the researchers noted.

“Hydroclimate in California is reliably unreliable,” said co-author John Abatzoglou, a UC Merced climate scientist. “However, swings like we saw a couple years ago, going from one of the driest three-year periods in a century to the once-in-a-lifetime spring 2023 snowpack, both tested our water-infrastructure systems and furthered conversations about floodwater management to ensure future water security in an increasingly variable hydroclimate.”

Hydroclimate whiplash is projected to increase most across northern Africa, the Middle East, South Asia, northern Eurasia, the tropical Pacific and the tropical Atlantic, but most other regions will also feel the shift.

“Increasing hydroclimate whiplash may turn out to be one of the more universal global changes on a warming Earth,” Swain said.

In California this week, although winds are fanning the extreme fires, it's the whiplash-driven lack of rain that suspended Southern California in fire season.

“There's not really much evidence that climate change has increased or decreased the magnitude or likelihood of the wind events themselves in Southern California,” Swain said. “But climate change is increasing the overlap between extremely dry vegetation conditions later in the season and the occurrence of these wind events. This, ultimately, is the key climate change connection to Southern California wildfires.”

Under a high warming scenario, California will see an increase in both the wettest and driest years and seasons by later this century.

“The less warming there is, the less of an increase in hydroclimate whiplash we're going to see,” Swain said. “So anything that would reduce the amount of warming from climate change will directly slow or reduce the increase in whiplash. Yet we are currently still on a path to experience between 2 degrees and 3 degrees Celsius of global warming this century — so substantial further increases in whiplash are likely in our future, and we really need to be accounting for this in risk assessments and adaptation activities.”

The research was supported with funding from The Nature Conservancy of California and the Swiss National Science Foundation.

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