Science: When it comes to reducing carbon footprints, many Americans need look no further than their front yards. The soil beneath those perfectly manicured carpets of green grass-the pride of many suburban homeowners-is pumping surprising amounts of carbon into the atmosphere. That's according to a study published this month in the Soil Science Society of America Journal, which concludes that the amount of carbon rising from the soil of residential lawns is significantly greater than that from the soil of...