What is locavorism? It's the conviction that food grown close to where you live is not only more nutritious and better tasting, but also less burdensome to the environment than mass-produced food shipped from distant agricultural complexes. The growing passion in this movement has fueled a fivefold increase in the number of farmers markets since 1994, giving homegrown produce hipster cachet from Brooklyn to Portland. First Lady Michelle Obama even ripped out part of the South Lawn to plant her own arugula, kale, and other vegetables. Locavores say that growing food close at hand greatly reduces the greenhouse gases produced by transport, making agriculture "greener." What's wrong with supermarket food? For locavores, nearly everything. Michael Pollan, author of The Omnivore’ s Dilemma and a guru of the locavore movement, says that America’s modern “food system” is responsible for 19 percent of fossil-fuel use, and contributes more than a third of total greenhouse-gas emissions. When you add up natural-gas-based fertilizers, petroleum-based pesticides, farm machinery fuel, processing, packaging, and transport, he computes that 10 calories of fossil fuel go into creating a single calorie of modern supermarket food – some 23 times more than it took to create a food calorie in 1940. “When we eat from the industrial-food system,” Pollan writes, “we are eating oil and spewing greenhouse gasses.” So what's the alternative? The central locavore argument is that for the sake of the environment, we should reduce the "food miles" that separate production from consumption. Why should Alaska salmon be shipped to China for filleting, then back across the Pacific to California to be sold and eaten? And when you know the farmer who grew your food, said Jill Richardson of the Organic Consumers Association, "your weekly food shopping nourishes your soul as well as your body."30 35 40 45 50 55 Is all this true? It may feel more virtuous to eat locally produced food, but some economists say the belief that it reduces greenhouse-gas emissions is largely illusory. To start with, transportation contributes less than 11 percent to the overall carbon cost of an average food item, according to a 2008 study by Carnegie Mellon researchers. Some distant places are so much better suited to growing certain foods that it's folly not to take advantage of them — olive oil in Italy, for example, or potatoes in Idaho. A study from New Zealand's Lincoln University found that because lamb there is raised on clover in sunlit upland meadows, it's four times more energy efficient for a Londoner to buy New Zealand lamb — despite the carbon burden of shipping it 11,000 miles — than British lamb that has to be fattened with cultivated grain. Locavore agriculture also loses the economies created by scale. Journalist Will Boisvert has calculated that a van "hustling 200 pounds of tomatoes from a Brooklyn micro-farm to a Midtown market" burns more gas per tomato than a fully loaded semitrailer would coming all the way from Florida. An upper-middle-class urbanite longing for "farm to table" fare may disdain those efficiencies, but they're vital for creating enough cheap food to feed the world's 7 billion people. Is locally grown food healthier? Not necessarily. A small farmer may be more inclined than a faceless multinational to avoid antibiotics and industrial feed, but he can't control everything. A recent report found that many eggs from chickens raised in community gardens in New York City contained elevated levels of lead, because such heavy metals are often present in urban soils. For all the distrust agribusiness has earned over the years, its output is inspected and traced, while many local providers' isn't. As Pierre Desrochers and Hiroko Shimizu point out in their book The Locavore's Dilemma, U.S. deaths from food-borne illnesses today are a fraction of what they were a century ago, when supply was more local. So is locavorism without merit? No — it has produced valuable insights about negative aspects of factory farming, and it clearly makes sense to buy local when natural conditions of season and environment favor certain vegetables, fruits, and animal products. But locavorism is not an environmental panacea or a practical replacement for all mass food production. Desrochers and Shimizu note that in parts of the world where people rely completely on locally produced food, such as sub-Saharan Africa, malnutrition and hunger are widespread and diets are monotonous. By eating globally, they argue, the modern world has created a "food cornucopia" that successfully feeds 6 billion people, and has reduced the percentage of the world's population suffering from malnutrition and starvation from 40 percent to 12.5 today. "Why," they ask, "have countless individuals worked so hard and for so long to create our globalized food supply chain if things were so great when most food was produced and consumed locally?"65 The bespoke locavore chicken Locavores disdain chicken raised in huge factory farms. So some New York restaurateurs are now sending table scraps from $18 salads and $75 entrées to a small Amish farm in Pennsylvania, in hopes of creating the ideal locavore chicken. Commercial chicken "is a crime," Ariane Daguin, who is running the new chicken business, told The New York Times. By raising poultry the right way, she is giving customers at Per Se, Daniel, the Gramercy Tavern, and other Manhattan foodie temples a chance to rediscover "what a chicken should taste like." The chefs sponsoring the effort say the payoff is happy, plump chickens that live twice as long — and at more than twice the price — as commercial birds. Their taste is said to have brought tears to the eyes of New York celebrity chef Jean-Georges V ongerichten. "It's a wonderful reaction to corporate poultry and corporate farming in general," said Matthew Mills, creator of a satirical show on food on the Cooking Channel. "But at the same time, it swings so far to the other side that it's almost an Onion headline."

using this context write me a claim and 2 pieces of evidence from this text for the question How does the author mainly structure this passage

Claim: The author mainly structures this passage by presenting the concept of locavorism and then providing evidence to both support and challenge its principles.

Evidence 1: "Locavores say that growing food close at hand greatly reduces the greenhouse gases produced by transport, making agriculture 'greener.'" (Paragraph 1)
Evidence 2: "Some economists say the belief that [locavorism] reduces greenhouse-gas emissions is largely illusory...transportation contributes less than 11 percent to the overall carbon cost of an average food item." (Paragraph 9)