Facebook
X (Twitter)
Reddit
Pinterest
Tumblr
Delicious
LinkedIn
StumbleUpon
Posts Tagged: Climate Change
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
|
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.
Climate scientist Daniel Swain joins UC ANR
“We are very excited to have Daniel Swain join UC ANR,” said Glenda Humiston, UC vice president for agriculture and natural resources. “He brings a unique blend of skills and expertise that are crucial to meet the challenge of climate change, here in California and across the globe. Daniel's research – and his ability to clearly explain the latest findings in climate science – can equip fellow academics, policymakers and communities with the vital tools they need to forge effective and sustainable solutions.”
Swain is known for his exceptional science communication skills, explaining weather and climate in terms easily understood by the public.
“I spend a great deal of time engaging directly with the public in California and beyond on weather, climate and disaster-related topics, so I'm thrilled to be joining UC ANR—where broad dissemination of research-based information is a key part of the mission,” Swain said. “I'm grateful for ANR's support for my unusual hybrid climate research and science communication role, and look forward to helping expand ANR's virtual and statewide reach in the years to come.”
In November, Swain was named one of Vox's Future Perfect 50 – “the thinkers, activists and scholars working on solutions to today's (and tomorrow's) biggest problems.” Vox wrote: “Our communities and institutions are largely unequipped to fully understand, let alone deal with, the impacts of climate change. That's where climate experts should, theoretically, come in. But knowing the science is one thing – being able to effectively communicate it is a whole other ballpark. Climate scientist Daniel Swain is that desperately needed liaison.”
On his widely read Weather West blog, Swain has been sharing his perspectives on California weather and climate since 2006. He hosts regular “virtual office hours” for the public on YouTube. On X/Twitter, he has more than 101,000 followers.
The “Weather Whisperer” fields hundreds of calls from reporters every year and has been the single most-quoted expert in recent years at UCLA, where he was a climate scientist in the Institute of the Environment and Sustainability. Last year, when Swain was seeking institutional support that would allow him to do science communication as well as research, a Los Angeles Times columnist wrote, “I certainly rely on Swain and other scientists to tell environmental stories.”
The term "Ridiculously Resilient Ridge" was coined in 2013 by Swain on his Weather West blog to describe the large, formidable high-pressure mass that persisted over the West Coast during winter and diverted storms away from California, contributing to the state's 2013-2017 drought.
Before joining UC ANR, Swain, who grew up in the Bay Area, was at UCLA and held a concurrent appointment as a research fellow in the Capacity Center for Climate and Weather Extremes at the NSF National Center for Atmospheric Research since 2018. While holding a 100% appointment with UC ANR, he will maintain his associations with UCLA and NSF NCAR.
Swain holds a Ph.D. in Earth system science from Stanford University and a bachelor's degree in atmospheric science from UC Davis.
He will be the keynote speaker at the California Irrigation Institute's annual conference on Jan. 27 in Sacramento. His talk is titled “Drier and Wetter in 21st Century California? Managing Increasing Hydroclimate Whiplash in a Warming World.”
In addition to posting on his blog at weatherwest.com, Swain is also on Twitter/X @Weather_West, Bluesky https://bsky.app/profile/weatherwest.bsky.social, YouTube https://youtube.com/@weatherwest, Threads https://threads.net/@weather.west and Mastodon https://mastodon.social/@weatherwest.
White House Summit explores impact of extreme heat, ways to adapt
UC ANR Small Farms Network supports small-scale and underserved farmers impacted by extreme heat
Ruth Dahlquist-Willard, interim director for the UC Sustainable Agriculture Research and Education Program, joined more than 100 participants from across the country at the first-ever White House Summit on Extreme Heat. Community representatives and practitioners met with federal agency representatives and Biden Administration officials to discuss successful locally tailored, community-driven practices to adapt to extreme heat as well as available federal resources.
In the agricultural sector, extreme heat events can cause heat illness in farmworkers, crop losses and changes in pest pressure. California crop losses due to drought, wildfire and heat were estimated at $239 million in 2023.
Disaster relief funds are available to help growers recover from lost production due to extreme heat. Since 2021, the UC ANR Small Farms Network has connected small-scale farmers with over $5.8 million in direct-to-producer relief funds for losses related to drought, flooding and other extreme weather events.
To further support small-scale farmers in adapting to the changing climate, Dahlquist-Willard and the Small Farms Network are evaluating how the extreme heat of summer 2024 impacted farmers. Farmers reported anecdotal observations that included:
- Shifting work hours to cooler parts of the day
- Closing farm stands and farmers markets due to extreme heat
- Crops ripening more quickly than expected, impacting harvesting and packing schedules
- Poor fruit set due to extremely high temperatures
The team is working to determine what damage symptoms on small-acreage California specialty crops can be attributed to extreme heat based on scientific literature and assessments from UC ANR colleagues. Understanding the impact of extreme heat on the farming community can help inform research and policy, ultimately equipping farmers with strategies to adapt to extreme heat events.
“It was inspiring to meet with leaders from around the nation who are working to support communities impacted by extreme heat and learn about the creative solutions they are implementing,” said Dahlquist-Willard. “The challenges faced by these communities make it all the more important to continue to work against climate change by reducing greenhouse gas emissions, as well as to develop new methods and resources to mitigate the effects of extreme heat and other climate impacts.”
The Extreme Heat Summit highlighted the Biden-Harris Administration's investments in climate reliance and put forth an Extreme Heat Call to Action calling upon public and private sectors to prepare for future extreme heat events. Communities and governments interested in participating are asked to use all available tools to protect people from extreme heat. Approaches and tools which could be used to protect people and resources from extreme heat are highlighted in the U.S. Climate Resilience Toolkit and the National Heat Strategy. Submissions for the Call to Action will be accepted through Nov. 1, 2024.
Further reading:
Heat Illness Prevention, UC Davis Western Center for Agricultural Health and Safety
Pathak et al., 2018. Climate Change Trends and Impacts on California Agriculture: A Detailed Review
UC's New Climate Action Goals: Frequently Asked Questions
Paper highlights how climate change challenges, transforms agriculture
As the climate continues to change, the risks to farming are only going to increase.
That's the key takeaway from a recent paper published by a team that included UC Merced and UC Agriculture and Natural Resources researchers. The paper dives into what those challenges are, how farmers are working to address them and what should come next.
"Climate Smart Agriculture: Assessing Needs and Perceptions of California's Farmers" was first authored by Samuel Ikendi, academic coordinator, with Tapan Pathak, UC Cooperative Extension climate adaptation in agriculture specialist, as a corresponding author. Both are based at UC Merced. Pathak is also a project director of National Institute of Food and Agriculture-funded project "Multifaceted Pathways to Climate-Smart Agriculture through Participator Program Development and Delivery," which supported this study. The study appeared in the open access journal Frontiers in Sustainable Food Systems.
The needs assessment was designed to understand farmers' perceptions and experiences with climate change exposures; the risk management practices they currently use; and what tools and resources would assist them in making strategic decisions.
Of the farmers surveyed, roughly two-thirds agree climate change is occurring and requires action. Even more said they are interested in learning more about the impacts of climate change on the agricultural industry. Most respondents said they experience greater climate change impacts on their farms today compared with 10 years ago.
Farmers were very concerned with water-related issues, with those in the San Joaquin Valley, Central Coast and Inland Empire areas particularly worried about a reduction in the availability of groundwater. Increased drought severity was a very significant concern among farmers in the Inland Empire, Central Coast and Southern regions. Farmers in the North Coast and Southern regions were concerned about increased damage to crops due to wildfire.
Closely related were temperature-related issues, including crop damage due to extreme heat.
Those who farm vegetables were more concerned about water availability for irrigation, while fruit farmers were more concerned about increased crop/water stress and increased crop damage due to extreme heat.
Many respondents said they are implementing climate adaptation practices including managing water resources, maintaining soil health and making more use of renewable energy sources. They are seeking insurance and government help to pay for these adaptations and increase their agricultural resilience, the researchers wrote.
The farmers expressed interest in learning more about measures they might take to mitigate climate change. But they cited significant barriers to this work, including government regulations, high implementation cost, labor access/cost, access to water and the availability of money to pay for it.
"Climate change is significantly altering California's highly diverse agricultural landscape, posing challenges such as increased water stress, heat stress, and shifting growing seasons," Pathak said. "Climate-smart agriculture practices can alleviate some of those stresses."
But, he said, research and UC Cooperative Extension efforts only have value if they lead to enhanced climate-informed decision-making at the local level.
"Assessing their level of knowledge, perception and needs will help in tailoring research and extension activities that are most relevant to farmers on the ground," Pathak said. "Results from this study could also provide important policy insights on financial incentives and technical assistance."
Webinars explore role of trees in climate change resilience, May 14-16
A free webinar series titled “Trees to the Rescue: Solutions for Climate Change” will be held on May 14-16, from 4 p.m. to 5:30 p.m. each day. The webinars are sponsored by the University of California Thelma Hansen Fund.
“The webinars aim to increase our understanding of the role of trees in mitigating and adapting to climate change, how to plant the right trees and keep them healthy in urban environments, and the challenges of increasing the number of trees at the local level,” said Annemiek Schilder, director of Hansen Agricultural Research and Extension Center, who is organizing the series. Hansen REC is operated by UC Agriculture and Natural Resources.
Participants will discuss some of the challenges and pitfalls of reforestation, urban greening and tree equity. They will also provide diverse perspectives on tree planting and maintenance efforts and policy at the local level.
“Anyone interested in learning about the importance of trees in urban environments and climate resilience, as well as tree retention in the landscape should join us,” she said.
The agenda for each 90-minute webinar is listed below. To register, visit https://bit.ly/HansenTreesWebinar.
Tuesday, May 14: Trees as a Tool for Climate Change Mitigation and Resilience
4 p.m. Welcome—Annemiek Schilder, Director of Hansen Agricultural Research and Extension Center
4:05 p.m. Opening Remarks—Matt LaVere, Ventura County Supervisor District 1
4:10 p.m. Improving Outcomes of Tree Growing and Forest Restoration Efforts—Karen Holl, Professor of Environmental Studies, UC Santa Cruz
4:50 p.m. Climate Resilience through Urban Greening—Edith de Guzman, UC Cooperative Extension Specialist, Water Equity and Adaptation Policy, UCLA
5:30 p.m. Closing—Annemiek Schilder
Wednesday, May 15: Optimizing Tree Survival in a Changing Climate
4 p.m. Welcome—Emma Volk, Production Horticulture Advisor, UCCE Ventura and Santa Barbara counties
4:05 p.m. Cooling Urban Heat Islands with Climate-Resilient Trees—Janet Hartin, Environmental Horticulture Advisor, UCCE Los Angeles and San Bernardino counties
4:30 p.m. Keeping Trees Healthy from Sapling to Maturity—James Downer, Environmental Horticulture and Plant Pathology Advisor Emeritus, UCCE Ventura County
5:05 p.m. Dealing with the Inevitable Threat of Exotic and Invasive Pests—John Kabashima, Environmental Horticulture Advisor Emeritus, UCCE Orange County
5:30 p.m. Closing—Emma Volk
Thursday, May 16: Tree Advocacy and Planning at the Local Level
4 p.m. Welcome—Julie Clark, Natural Resources Community Education Specialist, UCCE Ventura County
4:05 p.m. Native Tree Restoration with Partners and the Public—Joey Algiers, Restoration Ecologist, Santa Monica Mountains National Recreation Area
4:30 p.m. Panel Discussion (Joey Algiers, moderator):
- Joey Algiers, Santa Monica Mountains National Recreation Area
- Mireille Vargas, County of Ventura Sustainability Division
- Mikaela Randolph, Green Schoolyards America
- Jan Scow, Registered Consulting Arborist, Ojai Valley
- Max Young, Ventura Regional Fire Safe Council
5:30 p.m. Closing—Julie Clark
