Greenhouse gases are gases in the Earth's atmosphere that trap heat. They include carbon dioxide, methane, and nitrous oxide. These gases allow sunlight to enter but prevent some of the heat from escaping back into space, creating a "greenhouse effect." This process is essential for keeping our planet warm enough to support life. However, human activities, such as burning fossil fuels and deforestation, have increased the levels of greenhouse gases. This rise contributes to global warming and climate change, leading to extreme weather, rising sea levels, and other environmental issues. Reducing greenhouse gas emissions is crucial for a healthier planet.