Posts Tagged: Climate Change
The University of California and VOX Media have been producing a video series this past year that explores issues related to global climate change and UC's work to mitigate its effects. Previous episodes have examined food waste, nuclear power, goods movement and more. Episode 8, “The diet that helps fight climate change,” compares the greenhouse gas emissions of livestock and transportation globally, using some statistics that have been questioned by our UCCE scientists.
Data – and the way in which it is presented – matters a great deal. Although the video stresses moderation and doesn't explicitly urge consumers to go vegan, it states that if the world was to reduce its meat consumption, that decision alone could offset the emissions from a billion cars on the road by 2050. For the U.S., however, this contention is misleading, as the impact would be considerably smaller.
It's true that livestock emit methane and nearly all aspects of agriculture have a carbon footprint; however, U.S. animal agriculture is much more efficient than in other parts of the world. In the U.S., livestock are responsible for 3.8 percent of GHG emissions while transportation accounts for 26.4 percent, according to U.S. Environmental Protection Agency data. In California, 5.4 percent of GHG emissions are attributed to livestock and 37 percent to transportation, according to the California Air Resources Board.
While it is vital that scientists in UC ANR, and elsewhere, assist ranchers to continue diminishing the carbon hoofprint, it is also important to recognize that meat can serve as a high-quality protein source as part of a nutritious diet. The VOX video does note that not all livestock is raised equally, and that rangeland can be used to sequester carbon, but it neglects to mention that grazing cows also provide numerous ecosystem services, such as eating plants that could fuel wildfires and crowd out native wildflowers.
It should also be noted how livestock fit into the larger food system picture. Almost 60 percent of the world's agricultural land is grazing land and is unsuitable for producing crops. Ruminants serve a valuable role in the food system by converting the forages humans cannot consume into a nutrient-dense food.
UC ANR advisors and specialists continuously strive to improve livestock production practices; however, that is only one of many approaches we need to pursue to solve the challenges of climate change. Time, research and money should be invested where they will produce the most benefit for society. Encouraging people to focus on livestock, rather than on much larger sources of GHG emissions, can lead to policies that slow our efforts to develop more effective climate change solutions.
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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.
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.
Pottinger asked Ted Grantham, UC Cooperative Extension specialist in the Department of Environmental Science Policy and Management at UC Berkeley, whether the state's fish are adapted to periodic droughts.
Drought is one stressor, he said, but there are additional factors imperiling fish.
"California's native fish have been in steady decline for at least 50 years — in part due to dams, habitat degradation, and the introduction of non-native species," Grantham said. "Native fishes have developed several strategies to cope, but key to their long-term survival is their ability to recover from drought during wet years."
Grantham said there are at least three strategies that would help better manage the state's native fish.
- Better define the amount of water needed to sustain healthy fish populations.
- Create an accurate accounting system for tracking water availability and use.
- Recognize that not all streams are created equal. Some streams support more biological diversity.
The ecosystems science researcher said he is optimistic about the future.
"Although the drought has severely affected California's freshwater ecosystems, it also has raised awareness about the need to improve water management and better prepare for climate change," he said.
For more on threats to California native fish, read Identifying gaps in protecting California's native fish in the UC California Institute for Water Resources' blog The Confluence.