Tide, a Procter & Gamble brand, is putting cold-water laundry at the center of its plans to reduce greenhouse gas emissions. Tide says 75% of the CO2 emissions associated with its products happen during their use. P&G is planning an ad campaign this spring around the goal of switching 75% of household loads in North America to cold water. It says the change would prevent 27 million metric tons of total CO2 emissions this decade. Tide is also forming a pilot project with the start-up Opus 12 to explore making Tide ingredients out of captured CO2.