Global warming is the increase of the Earth's average surface temperature due to greenhouse gases building up in the atmosphere from human activities like burning fossil fuels. Some consequences of global warming include melting glaciers, rising sea levels, more extreme weather, and the extinction of polar bears. While global warming is a serious problem, individual actions like reducing energy usage, recycling, and driving less can help address it. Collective changes in areas like renewable energy and fuel efficiency can also make a difference if addressed promptly.