climate change

Arctic ice is melting. Coral reefs are disappearing. Sea levels are rising. These events are part of an even bigger problem: a change in Earth's climate. Over the past 100 years, global temperatures are slowly rising and weather patterns are changing. Human activities are the major cause. When we burn fossil fuels to produce energy, we add carbon dioxide to the atmosphere. This greenhouse gas is causing Earth's climate to warm.

Image credits: main image, courtesy NASA; Ed Mathez: courtesy of AMNH.