BIO205H5 Chapter 5: Climates and Soils BIO205
Document Summary
Solar radiation alone is not sufficient to warm the planet; gases in the atmosphere also play a critical role. Of the solar radiation that strikes earth, some is reflected back into space and the rest penetrates the atmosphere where much of it warms clouds and the planet"s surface. These warmed objects emit infrared radiation back toward the atmosphere where it is absorbed by greenhouse gases. The warmed greenhouse gases re-emit infrared radiation back toward earth, which causes the surface to warm further. Greenhouse effect: the process of solar radiation striking earth, being converted to infrared radiation and being absorbed and re-emitted by atmospheric gases. This means that greenhouse gases, which play such a major role in keeping our planet warm, compose only a small fraction of the atmosphere. The two most prevalent greenhouse gases are water vapor (h2o) and carbon dioxide (co2). Other naturally occurring greenhouse gases include methane (ch4), nitrous oxide (n2o), and ozone (o3).
