Reuters: The world needs to find smarter ways to feed a rising population while cutting emissions of laughing gas, a widely forgotten greenhouse gas that is stoked by the use of fertilisers, a researcher said on Friday. Nitrous oxide, best known for its mirth-producing qualities, is 310 times more powerful at trapping heat than carbon dioxide. Mainly emitted by farmed soil and intensified by fertiliser, it accounts for 9 percent of greenhouse gas emissions from human activity. …