Every five years, the government tries to tell Americans what to put in their bellies. Eat more vegetables. Dial back the fats. It’s all based on the best available science for leading a healthy life. But the best available science also has a lot to say about what those food choices do to the environment, and some researchers are annoyed that new dietary recommendations of the USDA (United States Department of Agriculture) released yesterday seem to utterly ignore that fact.

        Broadly, the 2016-2020 dietary recommendations aim for balance: More vegetables, leaner meats and far less sugar.

        But Americans consume more calories per capita than almost any other country in the world. So the things Americans eat have a huge impact on climate change. Soil tilling releases carbon dioxide, and delivery vehicles emit exhaust. The government’s dietary guidelines could have done a lot to lower that climate cost. Not just because of their position of authority: The guidelines drive billions of dollars of food production through federal programs like school lunches and nutrition assistance for the needy.

        On its own, plant and animal agriculture contributes 9 percent of all the country’s greenhouse gas emissions. That’s not counting the fuel burned in transportation, processing, refrigeration, and other waypoints between farm and belly. Red meats are among the biggest and most notorious emitters, but trucking a salad from California to Minnesota in January also carries a significant burden. And greenhouse gas emissions aren’t the whole story. Food production is the largest user of fresh water, largest contributor to the loss of biodiversity, and a major contributor to using up natural resources.

        All of these points and more showed up in the Dietary Guidelines Advisory Committee’s scientific report, released last February. Miriam Nelson chaired the subcommittee in charge of sustainability for the report, and is disappointed that eating less meat and buying local food aren’t in the final product. “Especially if you consider that eating less meat, especially red and processed, has health benefits,” she says.

        So what happened? The official response is that sustainability falls too far outside the guidelines’ official scope, which is to provide “nutritional and dietary information.”

        Possibly the agencies in charge of drafting the decisions are too close to the industries they are supposed to regulate. On one hand, the USDA is compiling dietary advice. On the other, their clients are US agriculture companies.

        The line about keeping the guidelines’ scope to nutrition and diet doesn’t ring quite right with researchers. David Wallinga, for example, says “In previous guidelines, they’ve always been concerned with things like food security—which is presumably the mission of the USDA. You absolutely need to be worried about climate impacts and future sustainability if you want secure food in the future.”

解析：D。根据题干中的Dietary Guidelines Advisory Committee’s scientific report可定位至原文第五段第一句。该句说到，所有这些观点以及更多的观点都出现在了膳食指南咨询委员会去年二月发布的科学报告中。这句话中的All of these points指的是前文提到的内容，需要回到第四段找。第四段最后一句指出，粮食生产所消耗的淡水量最大，是造成生物多样性丧失的罪魁祸首，也是耗尽自然资源的主要因素。由此可知，报告说明，农业消耗了大部分的自然资源，D项与此表述一致，其中Farming对应第四段最后一句中的Food production，consumes most of our natural resources对应该句中的a major contributor to using up natural resources，故正确答案为D。

错项排除：第四段前两句提到，动植物农业占全国温室气体排放总量的9%。这还不包括运输、加工、冷藏以及食物从农场到人们吃进肚子里所经过的其他运输点过程中所消耗的燃料。这里并没有说食物在途中会被污染，A项中的contaminated一词在原文中没有依据，故A项错误。B项利用文中出现的greenhouse gas emission作干扰，但still under debate无原文依据，故排除。C项利用diversity一词作干扰，文中第四段最后一句出现了biodiversity，但这里是说粮食生产导致了生物多样性的丧失，原文中并没有提到食物的多样性（food diversity），故C项错误。