Is tofu imported from China more environmentally friendly than beef from my local farmers’ market? If my family already consumes a lot, is having a third kid dooming the planet? Mark Fischetti and Kim Nicholas join us for a Please Explain on how your choices affect your carbon footprint. Fischetti is the Senior Editor of Sustainability for Scientific American. Nicholas is a Associate Professor of Sustainability Science at the Lund University Centre for Sustainability Studies (LUCSUS) in Sweden, whose piece for Scientific American is titled "A Hard Look in the Climate Mirror." Listeners, call in and tweet us with questions! This segment is guest hosted by DW Gibson.