Rangelands, water, carbon and global warmingLeave a Comment
By Bonnie Dickson and Laurel Rogers, USGS California Water Science Center March 25 2015 Posted by www.climate.calcommons.org
“Results from this study reinforce the role of open rangelands in capturing water and reducing runoff. Maintaining rangelands can help mitigate the effects of climate change and drought.”
Grassland habitats on rangelands in California’s Central Valley and surrounding foothills could decline by as much as 37 percent by 2100 due to changes in land use and climate, according to “Integrated climate and land use change scenarios for California rangeland ecosystem services: wildlife habitat, soil carbon, and water supply,” by USGS researchers funded by the California Landscape Conservation Cooperative. In addition to habitat loss, the study shows that increased development of rangelands for urban use exacerbates the ongoing issues surrounding rainwater runoff. When this issue is combined with periods of drought, the area will suffer from reduced opportunities for groundwater recharge, especially on deep soils. “Results from this study reinforce the role of open rangelands in capturing water and reducing runoff,” said Dr. Kristin Byrd, the study’s lead author and a physical scientist with the USGS. “Maintaining rangelands can help mitigate the effects of climate change and drought.”
Rangelands are the largest land cover by area in California, covering more than one-half of the state. Though more commonly known for livestock grazing, rangelands provide multiple ecosystem services such as habitats for fish and wildlife and carbon sequestration. Rangelands also provide opportunities for surface and subsurface water collection and storage. To better understand the potential detrimental effects of climate change and land use change on rangeland ecosystem services, scientists worked with ranchers and land managers to develop six scenarios for the Central Valley and surrounding foothills. The model scenarios were consistent with three Intergovernmental Panel on Climate Change emission scenarios. To date, there are few studies that examine the combined effects of climate and land use change on rangelands. “Results show the importance of accounting for recharge areas, which provide opportunities for water storage in dry years, in climate-smart land use planning efforts. Given projections for agriculture, more modeling is needed on feedbacks between agricultural expansion on rangelands and water supply,” said Lorraine Flint, co-author and research hydrologist with the USGS.
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In addition to biodiversity conservation, California rangelands generate multiple ecosystem services including livestock production, drinking and irrigation water, and carbon sequestration. California rangeland ecosystems have experienced substantial conversion to residential land use and more intensive agriculture.
To understand the potential impacts to rangeland ecosystem services, we developed six spatially explicit (250 m) climate/land use change scenarios for the Central Valley of California and surrounding foothills consistent with three Intergovernmental Panel on Climate Change emission scenario narratives. We quantified baseline and projected change in wildlife habitat, soil organic carbon (SOC), and water supply (recharge and runoff). For six case study watersheds we quantified the interactions of future development and changing climate on recharge, runoff and streamflow, and precipitation thresholds where dominant watershed hydrological processes shift through analysis of covariance.
The scenarios show that across the region, habitat loss is expected to occur predominantly in grasslands, primarily due to future development (up to a 37 % decline by 2100), however habitat loss in priority conservation errors will likely be due to cropland and hay/pasture expansion (up to 40 % by 2100). Grasslands in the region contain approximately 100 teragrams SOC in the top 20 cm, and up to 39 % of this SOC is subject to conversion by 2100. In dryer periods recharge processes typically dominate runoff. Future development lowers the precipitation value at which recharge processes dominate runoff, and combined with periods of drought, reduces the opportunity for recharge, especially on deep soils.
Results support the need for climate-smart land use planning that takes recharge areas into account, which will provide opportunities for water storage in dry years. Given projections for agriculture, more modeling is needed on feedbacks between agricultural expansion on rangelands and water supply.
By Kurtis Alexander March 21, 2015 Updated: March 21, 2015 9:06pm
When a panel of nutrition experts told the federal government last month that consuming beef was not only bad for humans but destructive to the environment, many thought the idea of eating sustainably had finally gone mainstream.
No longer would it be just the Bay Area and the likes of Portland and Vermont that weighed whether their food choices harmed the planet. Leaders in Washington would step up and promote farms that don’t waste water and spew greenhouse gases, and the wisdom of an Earth-friendly diet would resonate across a burger-loving nation. Not so fast. The panel’s advice for how the government should update its influential dietary guidelines has stirred a backlash, led by the meat industry and some members of Congress. They say panel members overstepped their mandate to counsel on nutrition. One online petition to reject the group’s environmental concerns, joined by plenty of people who simply want to enjoy their protein without hassle, demanded, “Hands off My Hot Dog.”
Supporters of the panel now worry that policymakers in charge of rewriting the food guidelines this year may dismiss any suggestion that people eat with the planet in mind, denying sustainability a place in the national dialogue. “I don’t know how the politics of this will play out,” said Marion Nestle, a New York University nutrition professor who recently taught a class at UC Berkeley, has written extensively on food policy and supports the advisory group’s findings. “But I will be very surprised if that (part on sustainability) comes out in the guidelines as strong as the committee suggested.”
Every five years, the U.S. Department of Agriculture and the Department of Health and Human Services are charged with updating the nation’s dietary recommendations. The work helps craft school and military menus and shapes the consumer-oriented food pyramid, now redesigned as a plate. And every five years, a food fight ensues because huge amounts of money are at stake, including the nation’s $10 billion-plus school lunch program. This is the first year, however, that the government’s advisory panel has significantly weighed environmental issues, drawing in a debate with a flavor that’s historically reserved for oil pipelines and auto emissions. While people are putting more and more thought into their food decisions, such as reducing pesticides and mercury in diets, those choices are often driven by personal health. Taking into account the well-being of a warming planet is not as common. And it’s certainly more abstract.
In the advisory panel’s 571-page report, the group says no food needs to be eliminated from the American diet, but it singles out “animal-based food,” particularly beef, as using a disproportionate share of land, water and energy and producing harmful greenhouse gases. Critics counter that the panel not only had no business discussing the environment, but also wasn’t qualified to do so. And they certainly didn’t like the panel’s bottom line: that eating less beef is an Earth-friendly move.
“We believe that sustainability is an important topic. It’s certainly one that cattle farmers and ranchers welcome,” said Shalene McNeill, director of human nutrition research for the National Cattlemen’s Beef Association. “But the panel members don’t have the expertise to take on the topic of sustainability. … Nutrition experts have typically not had that training.”
Sustainability is indeed a complex subject. No single measure exists for evaluating it, much less a universal seal of certification. Some people might favor a foreign food produced organically over a local one produced with pesticides, citing toxic agricultural runoff, while others might prefer the local food because it means less carbon dioxide emitted during transit. This month, heavyweights in the meat industry, including McDonald’s and Tyson Foods, announced the formation of the U.S. Roundtable for Sustainable Beef. The goal is to examine the concept of sustainability and see how beef producers might get on board. McDonald’s has said it wants to source sustainable beef by next year. Already, though, a subset of the industry claims to be operating sustainably. Efforts to raise cattle in harmony with the environment were pioneered decades ago in Northern California, where grass-fed herds have long roamed free of feedlots and growth hormones, and their meat has been welcomed at many Bay Area restaurants.
Grazing over feeding
“Not all ranching and farming entities are the same,” said sixth-generation rancher Loretta Swickard, whose family’s Five Dot Ranch doesn’t use antibiotics or hormones and pledges to responsibly manage its rangeland in nine Northern California counties. “We have a passion for what we’re doing, and we wouldn’t do it if we didn’t think we were benefiting the environment and the consumer.” Places like Five Dot Ranch have been praised for promoting grazing over feeding with mostly grains, which typically require more water and energy to produce. They’re also credited with treating animals more humanely and even producing healthier, tastier food. Since they embrace the spirit of sustainability that the federal panel is pushing, many of these producers believe they will get along fine no matter what the government says about beef.
But the question of whether their cattle are that much better for the planet is hardly settled. Cows inevitably generate methane, a potent gas that contributes to global warming, no matter how they’re raised. About 2.2 percent of the country’s heat-trapping emissions are owed to beef production, the equivalent of roughly 33 coal-fired power plants, according to the Union of Concerned Scientists. The recent dietary report concludes simply that a plant-based diet has “less environmental impact.”
Many in Congress are either not convinced or not interested in the advice, and are defending the beef industry. Several lawmakers, mostly Republicans, have criticized the panel’s report, saying “lean meat” in moderation should be encouraged in the American diet and that sustainability was beyond the scope of the advisory body. A letter this month from 30 senators to the USDA and the Department of Health and Human Services relayed these concerns. It also requested more time for stakeholders to weigh in before policymakers draft the guidelines, expected late this year. The public comment period has since been extended through May 8, with a hearing scheduled for Tuesday in Bethesda, Md.
As the debate rages, neither USDA Secretary Tom Vilsack nor Health and Human Services Secretary Sylvia Mathews Burwell has said whether sustainability will play a role in the dietary recommendations. New York University’s Nestle, who hosts the blog Food Politics, said recent efforts by Vilsack to calm worried beef producers suggest environmental concerns won’t be in the final guidelines. While dozens of health and environmental organizations have lined up to support the inclusion of sustainability, including the Johns Hopkins Center for a Livable Future and Friends of the Earth, they’re no match for big business, Nestle said. “They don’t have anywhere near the credibility (with policymakers) that the beef industry does,” she said. “The industry is talking dollars and jobs. And it’s un-American not to like beef.”
The National Cattlemen’s Beef Association and the meat processing sector cumulatively spent nearly $5 million on lobbying last year, according to the political money tracking website OpenSecrets.org.
Despite the push to leave sustainability out of the discussion, panel member Miriam Nelson, a nutrition professor at Tufts University outside Boston, said in an interview that the evidence linking food choices to environmental welfare has become too strong to ignore. “The science in the last decade is robust. It’s strong,” she said, noting that other countries have begun considering the environmental toll of food in dietary policies. “It seemed like it was the right time” for the U.S.
Conveniently, Nelson pointed out, foods that are less sustainable are also generally less healthful. The advisory panel, for example, considers red meat a health risk, and suggests cutting back on it. The environment becomes just one more reason to do so. Already the private sector has begun to recognize an increasing demand for environmentally friendly products, said Dave Rochlin, who runs an innovation program at the Haas School of Business at UC Berkeley and works with companies to reduce their impact on the climate.
Major corporations like General Mills and Walmart are starting to promote sustainability and have been buying competitors known for environmental commitments, such as Burt’s Bees and Ben and Jerry’s.
“There have always been pockets of consumer demand for sustainable products,” Rochlin said. “I don’t want to say it was a red state-blue state thing. But now, these products are becoming mainstream.” At Alfred’s Steakhouse in San Francisco, a landmark for beef lovers since 1928, the dimly lit dining room still boasts its old red leather booths, crystal chandeliers, jazz music heavy on the horns, and a meat locker proudly displaying its aged cuts. But the menu has a new item: grass-fed filet mignon from a small, local producer, among other Earth-conscious dishes. “It hasn’t always been like this,” said owner Marco Petri, whose family bought the restaurant more than 40 years ago. “This city has a low tolerance for big producers (now). … And people want to know where their food came from.”Down the street, outside Super Duper Burgers, which advertises all-natural beef and organic shakes, city resident Sam Smith, 28, said he watches what he eats, mainly for health reasons, but he’s also been factoring in the environment. “It’s become more important to me not just to cut back on how much meat I eat,” he said, “but to make sure I eat the right kind of meat.”