Certain gases in the atmosphere, such as carbon dioxide, methane, nitrous oxide, and CFCs, trap heat in a process similar to a greenhouse, causing global warming. As levels of these greenhouse gases increase due to human activities like burning fossil fuels and deforestation, the average temperature of the Earth is projected to rise 1.5-4.5°C by 2100. This warming could lead to sea level rise, more extreme weather, changes in agricultural patterns, and disruption of natural ecosystems. International agreements like the Kyoto Protocol aim to reduce greenhouse gas emissions and limit global temperature increase through strategies such as transitioning to renewable energy and making industry more energy efficient.