ScienceNews: Think about what you had for lunch: Was it a hamburger? A chicken sandwich? Barbecue? What about vegetables? Would it surprise you to learn that what you eat can affect the whole planet? It can — in a big way. Last week, scientists attending the American Association for the Advancement of Science meeting in Chicago presented new studies showing how food and its production affect the globe and its warming climate. The researchers had some bad news for meat-eaters (which is good news …