Analytical and environmental chemists are used to thinking about parts per million, tossing around the abbreviation ppm like it was no big deal. To help his students comprehend what ppm really means ...

We may hear about parts per million (ppm) of methane, or carbon dioxide, or some other component in our environment but how can we relate to this? What does it mean? It doesn’t sound like much in ...

Microbes that consume methane could be used to help slow global warming. Researchers have identified many methane-eating bacteria, known as methanotrophs, but in nature these organisms tend to take in ...