Missoulian: 350. Three. Five. Oh. That’s an important number for a Missoula nonprofit called GlobalWarmingSolution.Org. In fact, it’s a figure the group’s members hope will be shouted at Washington, D.C., and here’s why. The amount of carbon dioxide in the atmosphere is somewhere around 385 parts per million – and climbing like the thermostat. According to the membership network, it needs to be pushed down to 350 ppm at the most. That’s low compared with the 450 ppm …