 NEW YORK--BUSINESS WIRE--Today, Marsh McLennan NYSE: MMC, the worlds leading professional services firm in the areas of risk, strategy and people, unveiled the Climate Action Navigator from the Oliver Wyman Forum. The navigator helps senior leaders explore the actions they need to take to enable us to halve emissions by 2030, keeping a 1.5 degrees temperature rise in reach. The Climate Action Navigator helps public and private sector leaders plot a path through climate science. It identifi 