The ocean is full of very small but very useful creatures called microbes. Without them, none of the sea plants or animals you’ve seen would exist!
Acid rain is any precipitation that has an unusually low pH. It can be rain, snow, fog, etc. But what is a low pH and why is this a problem?
This backgrounder explains what greenhouse gases are and how they contribute to climate change.
This backgrounder describes how vehicle emissions work and how they affect air quality, including their contribution to smog.
What is the nitrogen cycle? How do human activities such as using fertilizer affect the nitrogen cycle? How can this cause greenhouse gases?