We frequently hear about volcanoes, eruptions, explosions, and probably think these things will never affect us, that volcanoes only exist at places far away. However, they should be a concern to everybody, since more than 50 volcanoes scattered throughout the world are active every year and their eruptions affect millions of people. Volcanic explosions produce clouds, which the atmosphere transports. This means that volcanic clouds can travel long distances and affect people that live far from their sources.

In the state of Maryland, a local politician claimed that sea level is rising because there are too many people putting boats on the open ocean! This is a true story! Is this or similar claims possible? Imagine if all of the people in the world agreed to go float on the ocean at the same time! Could that result in a significant sea level rise, perhaps even destroy low-lying nations such as Bangladesh?