Christian Science Monitor: Around the world Saturday, environmental activists touted the number “350” as a way to recognize the seriousness of global climate change. It’s not a secret code. The number refers to the concentration of carbon in the atmosphere — meeting a goal of 350 parts per million (ppm), which is considerably less than the current level of 387 ppm. The “International Day of Climate Action” includes more than 4,500 events in 173 countries. Everything from skiers in New Zealand spelling …