Posts Tagged: climate change
A new study out of UC Riverside projects an increase in rain and snow in California due to climate change, reported Matt Smith on Seeker.com. Anthropogenic impacts on climate are expected to produce a chronic El Niño-like weather pattern off the Pacific coast of the U.S., leading to about 12 percent more rain and snow by 2100.
The study used a newer computer model and relied on other models that have a better record of simulating precipitation and the effects of an El Niño on the state. El Niño, the cyclical warming of the Pacific Ocean near Earth's equator, typically produces warmer temperatures across much of the United States and more rainfall over California.
Meanwhile, an article by Joshua Emerson Smith in the San Diego Union-Tribune presented less-welcome climate change news. It concluded that wildfires are expected to get longer and more intense in California due to climate change.
“We will need some very new approaches to deal with both the increasing hazard of fire and our increasing exposure to it,” said Max Moritz, UC Cooperative Extension specialist in fire ecology and management at UC Berkeley's College of Natural Resources. “The situation we have created is dangerous, and without a major shift in perspective it will only get worse.”
There are ways to limit the ignition of the wildfires. The article said about 95 percent of all wildfires are caused by people, so it's important to be aware of fire-safe practices pertaining to home maintenance, campfires, target shooting, vehicle use and other outdoor activities.
Here are a few examples of fire-safe best practices:
- Mow lawns in the morning before it gets too hot. Never mow when it is windy or extremely dry. Avoid rocks when mowing; metal blades can cause sparks when they hit rocks.
- Don't drive a vehicle on dry grass or brush. Don't allow vehicle brakes to wear thin, as thin brakes can cause sparks. Carry a fire extinguisher in the car.
- Maintain 100 feet of defensible space around homes in fire-prone areas. UC ANR experts recommend a five-foot zone immediately adjacent to the home be completely devoid of plants and anything combustible.
To help California forest property owners adapt to the changing climate, UC Agriculture and Natural Resources (UC ANR) has produced a 13-page peer-reviewed paper that outlines actions owners can take to sustain their forests' value even when temperatures rise.
“Managers of forest land have always had to adapt to changing conditions – such as markets, urban encroachment, droughts and floods,” said Susie Kocher, UC Cooperative Extension forestry and natural resources advisor. “We wrote this paper to help forest managers better understand the evolving science of climate change and how they can help their forests adapt to the climate of the future.”
Forests are shaped by the climates in which they grow. The current rapid pace of climate change has not happened for thousands of years, according to climate scientists. Nevertheless, the authors assure forest landowners that there are land management decisions they can make to ensure the resiliency of their resources, and perhaps even improve them.
“Some trees may grow faster under the warmer conditions we experience with climate change,” Kocher said, “especially those at highest elevation where there is adequate precipitation.”
The paper details the solid scientific evidence that indicates the rise in global average temperatures over the past 100 years. The temperatures, it says, “will likely continue to rise in the future, with impacts on natural and human systems.”
The document provides specific recommendations for care of three common types of forest in California: mixed conifer, oak woodland and coastal redwood forests.
Mixed conifer forests – typically composed of white fir, sugar pine, ponderosa pine, incense cedar and California black oak – are susceptible to moisture stress caused by warmer temperatures and reduced snow and rain. The drier conditions make the trees more vulnerable to fire and insect attack.
The drought of 2010-2016 has already had a substantial impact on mixed conifer forests in the Sierra Nevada. Aerial detection surveys show that more than 102 million trees have died since 2010; more than 62 million died in 2016 alone.
The UC ANR climate change adaptation paper suggests reducing competition for water by thinning trees and managing for species and structural diversity. The authors suggest property owners consider the source of seedlings when planting new trees.
“Select seedlings adapted to a slightly lower elevation or latitude than your property,” Kocher said. “These would be more likely to thrive under the 3- to 5-degree warmer temperatures we expect in 50 years or so.”
Oak woodlands are widely distributed and diverse in California, which gives them moderate to high capacity to adapt to climate change. Mature oaks are more resilient than young trees and seedlings.
One potential impact of climate change on oak woodlands is increasing precipitation variability and increasing spring rains. The moisture change could increase the spread and prevalence of Sudden Oak Death (SOD), a disease caused by a bacterium that was introduced into California from outside the U.S. SOD is primarily a concern in areas with tanoaks in Central to Northern California coastal areas.
“To reduce the spread of sudden oak death, land owners should prevent the movement of infected leaves, wood and soil,” according to the paper.
The primary concern for coastal redwood forests is the decline in fog. Fog frequency in coastal redwoods is 33 percent lower now compared to the early 20th Century. Less fog and rain plus warmer temperatures would leave coastal areas where redwoods typically thrive drier. But that doesn't mean redwoods will disappear. Areas with deep soil and areas close to streams and rivers may provide refuge for redwood forests.
The new publication, Adapting Forests to Climate Change, can be downloaded free from the UC ANR Catalog. It is the 25th in the Forest Stewardship series, developed to help forest landowners in California learn how to manage their land. It was written by Adrienne Marshall, a doctoral student at the University of Idaho; Susie Kocher, UC Cooperative Extension forestry and natural resources advisor; Amber Kerr, postdoctoral scholar with the UC John Muir Institute of the Environment; and Peter Stine, U.S. Forest Service.
It's almost that time again—time for the annual “Beer for a Butterfly” contest or “Suds for a Bug.” If you're out and about on Jan. 1, start looking for that cabbage white butterfly. But you're going to have to beat the sponsor, noted butterfly expert Art Shapiro, UC...
Improved soil promises to help farmers use less water and reduce carbon in the atmosphere, reported Ezra David Romero on Valley Edition, a one-hour weekly program that airs on KVPR-FM.
The five-minute story, which begins at the 30:30 mark, focuses on CDFA's new Healthy Soils Initiative. The program is expected to allocate $7.5 million for farmer incentives to use practices that will improve soil health and reduce greenhouse gas emissions. These are practices that are already in place on some innovative valley farmers, including two that are active in the UC Agriculture and Natural Resources' Conservation Agriculture Systems Innovation center.
Jesse Sanchez, manager at Sano Farms in Firebaugh, said 15 years ago, tractors were rolling across the 4,000-acre tomato farm all the time. Now, the farm features cover crops in the winter, reduced soil tillage, irrigation with super-efficient buried drip tape and lower fertilizer needs. The result is a one-third drop in water use and a 75 percent reduction in diesel to fuel tractors, Romero said.
Many of the farm's tractors have been sold. "We don't want to see them no more," Sanchez said.
Retired Madera County farmer Tom Willey discussed the critical importance of soil care he learned as a long-time organic vegetable grower.
"It's the survival of our species," Willey said. "The soil is the thin skin of the earth that we all exist on. Our lives are bound up in the health and productivity of the soil."
UC Cooperative Extension specialist Jeff Mitchell noted the challenges that farmers face in making soil care changes. “A real part of the challenge for California farms is the high-value nature of the production systems, the crops themselves, and some difficult challenges in terms of the diversity of the crops," he said.
A UC Santa Barbara study concluded that planting a home garden can cut carbon emissions to the atmosphere. However, if gardening isn't done right, it could actually contribute to greenhouse gas emissions, reported Nathanael Johnson on Grist.org.
The article looked at five factors that impacted greenhouse gas emissions in home gardens:
- Reduction of lawn area due to replacement by the garden
- Reduction of vegetables purchased from the grocery store
- Reduction in the amount of greywater sent to treatment facilities due to diversion to irrigate the garden
- Reduction in amount of household organic waste exported to treatment facilities due to home composting
- Organic household waste is composted for use in the garden
The abstract of the research article, written by David Cleveland, sustainable food systems professor in the Department of Geography, said:
"We found that (gardens) could reduce emissions by over 2 kg CO2e kg−1 vegetable, but that results were sensitive to the range of values for the key variables of yield and alternative methods for processing household organic waste."
In his Grist story, Johnson provided key points from the research that can help ensure the home garden is climate smart:
- The main reduction from gardening comes from diverting food waste from the landfill, where it rots and emits methane and nitrous oxide. Food waste must be properly composted to prevent the emissions.
- Planting a garden then forgetting about it ends up emitting more greenhouse gases than if you never started.
The article suggests that Californians contact their local UC Master Gardener program for assistance in properly managing a home vegetable garden. Johnson spoke to Kerrie Reid, the UC Cooperative Extension environmental horticulture advisor in San Joaquin County.
"Reid doesn't abandon her plants midway through summer, and she doesn't over-plant and then end up throwing out dozens of thigh-thick zucchinis," Johnson wrote. "Sure, when the cucumbers peak, there are more than she and her husband can eat, she confesses, but they share with their neighbors. The neighbors also come over to harvest herbs from the sidewalk."
The article said readers can find their own version of Reid by looking up a local UC Cooperative Extension Master Gardener program.