Agence France-Presse: A Japanese company said Friday it had conducted the world’s first spot trade in carbon credits, predicting the nascent market will grow as countries step up efforts to tackle global warming. Under the Kyoto Protocol, industrial countries must cut greenhouse gas emissions by 2012 but can earn credits by buying from those who have met their targets or by supporting environmentally friendly projects overseas. Japanese trading house Marubeni Corp. said it had sold the equivalent of …