Hennessy

Glossary

Greenhouse effect

A phenomenon in which the lowest layers of the atmosphere prevent the re-emission of the sun's rays that have already hit the Earth. The air temperature is then higher than it should be, because the lower layers of the atmosphere contain gases (CO2, CH4, water vapor) that trap the heat radiation sent back by the Earth. This is a natural phenomenon that is increased by the emission of carbon dioxide and other greenhouse gases due to human activities.