Unit 1: Ecosystems

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?

Ever wonder how fish survive in the cold waters of the Arctic and Antarctic? It’s partly because of a brilliant evolutionary adaptation.

Scientists have accumulated so much evidence in the theory of evolution that it is one of the most widely-accepted theories in science.

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.

Explore how walking on soil changes how water soaks into the ground and why that matters to gardeners and farmers.

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.

Water is a precious natural resource. What happens if it gets polluted? Learn how water can be cleaned with this hands-on activity?

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?

14 images of some plants such as carrots, cabbage and leeks whose roots, stems or leaves are used for food