Big Idea: The biosphere, geosphere, hydrosphere, and atmosphere are interconnected, as matter cycles and energy flows through them.

Learn about the categories, or phylum, of the plant kingdom with examples from each.

Learn about the important plant functions of photosynthesis, respiration and transpiration

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?

Make a model of the water cycle and find out how water moves around on planet Earth.

Oceans absorb the greatest amount of solar radiation on Earth. Ocean warming can lead to glaciers melting and ocean acidification.

Explore the greenhouse effect and learn about the impacts it can have on the environment.

Can carbon offsets help you reduce your environmental footprint, practice sustainable living and fight climate change?

This backgrounder explains what greenhouse gases are and how they contribute to climate change.

Biofuels like ethanol might help fight climate change. But they can contribute to food insecurity and greenhouse gases in ways that might surprise you.

What is the nitrogen cycle? How do human activities such as using fertilizer affect the nitrogen cycle? How can this cause greenhouse gases?

Temperature is an important part of life on Earth and life in space. This backgrounder explains what temperature is, how it affects people and how it is controlled on the International Space Station.