The greenhouse effect occurs when greenhouse gases in the atmosphere, such as carbon dioxide and methane, trap heat radiated from the Earth's surface. The greenhouse effect was discovered in 1824 by Joseph Fourier and was later experimentally studied by John Tyndall in 1858 and quantified by Svante Arrhenius in 1896. Greenhouse gases act like the glass of a greenhouse, allowing sunlight to pass through but trapping heat, which warms the Earth's surface and lower atmosphere. Increased levels of greenhouse gases from human activities like burning fossil fuels are enhancing the greenhouse effect and leading to problems such as rising sea levels and health issues.