Hi there! The level of carbon dioxide affects the global temperature, because it causes heat to be trapped into the atmosphere and heat the Earth up. CO2 (formula for carbon dioxide) is a naturally made gas formed by breathing, but lots of it is bad for the planet. Human activities like driving cars and running factories add much more toxic gasses into the environment. Global warming is the cause of melting ice caps, which leads to rising sea levels, and is also the cause of some plant and animal species dying out.
