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Posts Tagged: climate change

The food vs. fuel debate: Growing biofuel in the U.S.

Studies suggest biofuel can be grown on 'marginal land,' but no standard definition of 'marginal land' exists.
In order to slow global climate change and achieve greater energy independence, Americans are showing an increasing interest in switching over to clean, renewable fuels made from home-grown crops. In fact, Congress has mandated that at least 16 billion gallons of cellulosic ethanol be added to the U.S. fuel supply by 2022.

However, estimates suggest that growing crops to produce that much biofuel would require 40 to 50 million acres of land, an area roughly equivalent in size to the entire state of Nebraska.

“If we convert cropland that now produces food into fuel production, what will that do to our food supply?” asks Maggi Kelly, UC Cooperative Extension specialist and the director of the UC Agriculture and Natural Resources Statewide IGIS Program. “If we begin growing fuel crops on land that isn't currently in agriculture, will that come at the expense of wildlife habitat and open space, clean water and scenic views?”

Kelly and UC Berkeley graduate student Sarah Lewis are conducting research to better understand land-use options for growing biofuel feed stock. They used a literature search, in which the results of multiple projects conducted around the world are reviewed, aggregated and compared. 

“When food vs. fuel land questions are raised in the literature, authors often suggest fuel crops be planted on ‘marginal land,'” Kelly said. “But what does that actually mean? Delving into the literature, we found there was no standard definition of ‘marginal land.'”

Kelly and Lewis' literature review focused on projects that used geospatial technology to explicitly map marginal, abandoned or degraded lands specifically for the purpose of planting bioenergy crops. They narrowed their search to 21 papers from 2008 to 2013, and among them they found no common working definition of marginal land.

“We have to be careful when we talk about what is marginal. We have to be explicit about our definitions, mapping and modeling,” Kelly said. “In our lab, we are trying to understand the landscape under multiple lenses and prioritize different uses and determine how management regimes impact the land.”

The research report, titled Mapping the Potential for Biofuel Production on Marginal Lands: Differences in Definitions, Data and Models across Scales, was published in the International Journal for Geo-Information.

Click here for this story in Spanish.

An initiative to improve energy security and green technologies is part of UC Agriculture and Naturalist Resources Strategic Vision 2025.

 

Posted on Friday, November 21, 2014 at 7:45 AM
Tags: biofuel (1), climate change (25), Maggi Kelly (1)

Saving the Mojave desert tortoise

Saving the declining populations of Mojave desert tortoise is a big challenge. But scientists think that raising newborn “hatchling” tortoises in a controlled environment in the Mojave National Preserve for a year, then releasing the juvenile tortoises into the wild, may help save this threatened species.

The protected tortoises — which live up to 80 years and can go without water for a year — have existed for eons, but are now being decimated by habitat loss and predation. Professor Brian Todd, in the Department of Wildlife, Fish and Conservation Biology at UC Davis, worries that the increasing use of Southern California deserts for solar and wind energy, will add to the loss of tortoise habitats, and add further pressure to regional wildlife habitats. While developing renewable energy to combat climate change is a good thing, in this case it impacts desert species and their habitats.

Professor Brian Todd, UC Davis, with a Mojave desert tortoise.
Stepping up to the plate to save the Mojave desert tortoises is a triad of academics, government agencies, and corporations, who recently created the Ivanpah Desert Tortoise Research Facility. The new facility, located in the Mojave National Preserve, was designed for scientists to conduct research on juvenile tortoise survival. It was constructed largely by Chevron and Molycorp, and is managed by the National Park Service. Scientists from the University of California, University of Georgia, and elsewhere, are conducting a 15-year study to see if hatchlings released into the wild and/or relocated elsewhere can survive and reverse the population decline.

We can all keep our fingers crossed that this research will preserve desert tortoise populations, and serve as a model for conserving biodiversity.

Additional information:

  • “Protecting the desert tortoise,” video of UC Davis researchers and desert tortoises.
  • “Habitat selection, space use, and factors affecting recruitment of desert tortoises in the Mojave National Preserve”; Brian Todd website, UC Davis
  • “Baby desert tortoises get a headstart in the Mojave,” by Andy Fell and Kat Kerlin, Egghead blog, UC Davis. With a video of tortoises and scientists.
    A hatchling Mojave desert tortoise.
  • “Tortoise territory,” by Robin DeRieux, CA&ES Outlook magazine (see pages 2 and 10), UC Davis, spring/summer 2012.
  • “Mojave National Preserve celebrates dedication of Ivanpah desert tortoise,” Mojave National Preserve website.

Desert tortoises are well camouflaged in the California desert.

Posted on Tuesday, September 16, 2014 at 9:44 AM

Connecting wildfires to climate change and drought

Longer summers, less moisture and warmer climates are predicted for California's Sierra Nevada mountains. These changing patterns bring frequent droughts and extended wildfire seasons — as seen from the current extreme drought. The question no longer is whether wildfires will be more common or more intense — they already are — but how forest managers want these fires to burn.

Jens Stevens, a postdoctoral researcher in disturbance ecology at the University of California, Davis, has tracked how forests thinned for wildfire react to high-intensity burns. The answers he found touch on growing concerns over how the state can protect its forests.

Under the context of climate change, Stevens studies how understory plants recover from wildfires, measuring the effects fuel treatments — such as the thinning of small trees — have on the way these forests burn.

Postdoctoral researcher Jens Stevens (right) inspects an untreated forest after a wildfire.
Historically Sierra forests had gaps and openings, which prevented the spread of fires. More than a century ago land management agencies began a campaign of extinguishing all wildfires. Today's forest floors are blanketed with litter — fallen branches, leaves and shrubs — and many of the fire-tolerant pines have been replaced by firs, which handle shade well but act as fuel sources.

Stevens' research showed fuel treatments encourage resilience to wildfires, giving forests a greater ability to withstand a burn. Under really hot, dry summer conditions this makes a powerful difference.

“If you get warmer temperatures you're going to dry out the fuels,” says Stevens. “If we want to retain forest-dominated landscapes, we don't have the choice of doing nothing, because eventually these stands are going to burn."

To preserve forests, Stevens looked to native plant diversity under each management strategy. After a high severity fire, the tree canopy is non-existent. This new high-light environment favors other species, such as shrubs and flowering plants, which crowd out young trees.

A treated forest has more resilience to high-intensity wildfires.
In treating a stand before a fire, land managers are already encouraging plant diversity and when the stand burns, diversity increases even more, Stevens discovered.

While the treatments do protect the forest and encourage plant diversity, they are expensive and lead to uncertainty over how sensitive wildlife species are affected. Yet these areas will burn eventually, Stevens argues. The choice is either a more open forest or no forest at all.

He points out research by UC Davis ecologist Malcolm North, which shows the current pace of treatments can't keep up with the extent of Sierra forests that have been fire suppressed. The US Forest Service can treat up to 40 percent of a forest before managers must start over for follow-up treatments. The other 60 percent doesn't get touched.

“So the only real way to address that is to let the fire do the work for you,” says Stevens.

The proposal North and his colleagues arrived at relies on “firesheds.” These fire-prone areas would have boundaries that allow officials to efficiently manage the fires. If a burn begins after a treatment, they don't put it out. Allowing the fire to burn fuels they would otherwise be removing frees up resources to treat other areas.

“So if it's going to burn,” says Stevens, “you need to figure out ways the fire's going to give you your desired outcome.”

Watch Stevens explain more in his seminar.

This post was adapted from a longer piece by the UC Davis Department of Plant Sciences.
 

Posted on Wednesday, July 16, 2014 at 10:17 AM
  • Author: Brad Hooker

Berkeley team tackles environmental “critical zone”

A segment of the Eel River as it flows through the Angelo Coast Range Reserve in northern California. Photo: Christopher Woodcock

UC Berkeley scientists will receive $4.9 million over the next five years to study the nearly 10,000 square kilometer Eel River watershed in Northern California and how its vegetation, geology and topography affect water flow all the way to the Pacific Ocean.

What the researchers uncover will help improve global climate models and modeling tools that can be used by state or regional decision makers to guide planning. Their discoveries may eventually allow scientists to predict the impact of changing climate and land use on future droughts, floods and supplies of water for drinking and agriculture.

Funded by the National Science Foundation, the Eel River Observatory is one of four new Critical Zone Observatories that received grants late last year, bringing the total number of such observatories to 10. All focus on the so-called “critical zone”: the thin veneer of Earth, from the bottom of the groundwater to the tree tops, that is critical to aquatic and terrestrial life as the source of fresh water and site of soil formation from rock.

Bill Dietrich (in hat) with students at his Angelo Reserve hillside study site, dubbed Rivendell after the land of the elves in Lord of the Rings. Photo: Mary Power
The Eel River is increasingly under pressure because of illegal marijuana cultivation, wine grape growing and other uses that extract water from the river and threaten one of the state’s largest Coho salmon runs. In addition, warming waters in recent years have led to outbreaks of blue-green algae that produce enough toxins to kill dogs that drink the water. The river is currently stressed by the driest winter in decades.

“Whatever the agricultural use in the future, we will see increasing demands on a decreasing water resource,” said observatory director William Dietrich, UC Berkeley professor of earth and planetary science and an expert on the processes that shape landscapes.

Other UC Berkeley faculty members involved in the new project include professors Jill Banfield and Inez Fung of earth and planetary science and of environmental science, policy and management; earth and planetary science professor Jim Bishop; environmental science, policy and management assistant professor Stephanie Carlson and professor Mary Firestone; integrative biology professor Mary Power; and civil and environmental engineering assistant professor Sally Thompson.

“The critical zone provides most of the ecosystem services on which society depends, such as clean water, food, nutrients, soil and carbon storage,” said Roger Wakimoto, NSF assistant director for geosciences. “Researchers at the new CZO sites will investigate the past evolution and present state of the critical zone to predict how Earth’s surface will evolve in response to future human activity and to climate change. The results will provide the scientific basis for decision-making on how humans can best mitigate, adapt and respond to both slow and abrupt environmental changes.”

Read more.

Posted on Tuesday, January 28, 2014 at 12:35 PM
  • Author: Robert Sanders
Tags: climate change (25)

Is livestock’s contribution to climate change still being overestimated?

Frank Mitloenher
In a 1,000 year old village in Germany (Juehnde), methane is not a dirty word. The recovered methane from a manure-fueled bioreactor feeds the burners that heat water for every household in the village. The same hot water provides heating. These households benefit from living adjacent to a livestock economy whose manure was once just a smelly nuisance. The manure is transported by truck to an enclosed bioreactor, thereby reducing odor and feeding a system that powers an entire community. Frank Mitloehner once called this village home. Now a professor and air quality UC Cooperative Extension specialist in the Department of Animal Science at UC Davis, Mitloehner thinks that if this village can do it, so can California. 

It is easy to see how Mitloehner was inspired to study ways that California can take advantage of its plentiful supplies of animal methane. In eight bovine bio-bubbles that function as airtight barns, he captures and measures every emission from his resident livestock in order to understand how methane emissions vary with feed and herd management.

At Davis, a commercialized version of a similar methane bio-reactor has been patented and licensed by Ruihong Zhang, professor in the Department of Biological and Agricultural Engineering at UC Davis. It has been constructed at the local landfill and will be used to demonstrate a sustainable village on the UC Davis campus.

Mitloehner recently hosted a seminar for the Western Center for Agricultural Health and Safety at Davis. Since the Food and Agriculture Organization of the United Nations (FAO) committee released their 2006 report entitled, “Livestock’s Long Shadow,” he has challenged two key misleading sentences in their report. The phrase compared the contribution of livestock emissions to that of transportation. By saying the contributions to climate change were similar, the report led many environmental advocates to the conclusion that eating less meat was the equivalent of taking cars off the road, setting up a meat vs. miles tradeoff that exaggerated the methane contributions of livestock everywhere. 

Mitloehner’s response was the publication Clearing the Air, Livestock’s Contribution to Climate Change. After his paper was released, BBC, CNN and other media published his science-based estimate that the livestock contribution in the U.S. is 3.4 percent of U.S. emissions. Globally, 18 percent of warming was estimated to be livestock related. This estimate included livestock in the broadest sense - changes in land use, deforestation and desertification in developing countries. 

Bio-bubble at UC Davis.
In spite of Mitloehner’s paper, the meat vs. miles perception has persisted among advocates, while press about transportation GHG has dwindled. Toyota took advantage in their advertising by showing how Prius emissions were more favorable than those of a sheep. 

Nonetheless, Mitloehner showed that U.S. methane emissions remain flat, while developing countries are increasing animal production to meet the demand for eggs, meat and dairy, especially Asia. But why is the U.S. so low?

Mitloehner shared a few facts that help explain the phenomena:

  • The U.S. has fewer dairy cows. Today’s 9 million dairy cows supply 60 percent more milk than the 16 million cows in production in 1950. That means there is increased efficiency per cow for the same methane produced. 

  • Thirty percent of the methane in dairy production is from manure in ponds. There is the potential for recovery on the approximately 1,500 California farms, where the average herd size is 1,100 head.

  • Methane has 20 times the warming potential of carbon dioxide, but when burned to heat water or to generate power, its warming potential is reduced by a factor of 20.

  • The more fiber in the feed, the more methane is released by the rumen of the animal. One dairy cow in the U.S. produces an average of 20,000 lbs of milk per cow annually, the same amount of milk as five cows in Mexico, or up to 100 cows in India for the same, or less methane per cow. Reasons: low fiber diet, less parasites and less disease result in large differences in production per cow.

Mitloehner occupies that middle space between the economically driven farmers who survived years of falling milk prices and the sustainable advocates that want dairy to either disappear entirely or retreat into historical practices. When he is not serving on the President’s Council of Advisors on Science and Technology (PCAST) or the National Academies Institute of Medicine, he keeps company with local farmers and students and answers to science. 

Dairy addicts like myself, whose ancestors have evolved on milk for over 10,000 years, are likely to continue to frequent the organic dairy cases, hopeful that there are mutual benefits to paying higher prices for local labels in returnable glass bottles as a way to sustain the farms.

In reality, California has been exporting surplus dairy products to growing populations since the 1890s and that won’t change soon. Those markets do more to keep dairies profitable than my weekly milk and yogurt purchase. Lactose for pharmaceuticals and whey proteins for infant formulas are shipped internationally from several of California’s mammoth cheese factories, sometimes worth more the cheese itself. 

Mitloehner believes that “sustainable intensification” is the solution to keeping local dairies viable. He believes that science will provide the path to better regulation. The dairy nations that seem determined to get at the truth - New Zealand, France, Ireland and the Netherlands - have formed an international partnership at FAO entitled LEAP to address the issues. Mitloehner's leadership a chair of the partnership will keep methane bioreactors on the agenda.

More information: 

Mitloehner tells the story of how he neutralized errors in the FAO report “Livestock’s Long Shadow” (YOUtube).

LEAP site at the FAO.  NGOs include World Wildlife Federation and Greenpeace. Mitloehner said that Greenpeace is also a partner although not listed on the site. Workshop materials available for download. 

July 2012 opinion post by Robert Goodland at New York Times food blog. This is an example of criticism of Mitloehner’s role as head of the FAO partnership LEAP (Livestock Environmental Assessment and Performance). 

Posted on Monday, December 9, 2013 at 7:49 AM
Tags: climate change (25), dairy cattle (1), livestock (1), milk (1)

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