Geography · Ch 13 — Composition and Structure of Atmosphere
Gases
Gases
The atmosphere is a mixture of gases, but not all gases play an equal role in the earth’s weather and climate. Two gases stand out for their special functions: carbon dioxide and ozone. Each behaves differently with radiation, and each has a distinct effect on the temperature of the planet.
Carbon dioxide is meteorologically a very important gas. Its importance lies in how it treats incoming and outgoing radiation. It is transparent to incoming solar radiation, meaning sunlight passes through it easily and reaches the earth’s surface. But it is opaque to outgoing terrestrial radiation — the heat that the earth radiates back towards space. Carbon dioxide absorbs a part of this terrestrial radiation and reflects some of it back towards the earth’s surface. This trapping of heat is what makes carbon dioxide largely responsible for the greenhouse effect.
The volume of most other gases in the atmosphere remains constant, but the volume of carbon dioxide has been rising over the past few decades. The main reason for this rise is the burning of fossil fuels. As a direct consequence, the temperature of the air has also increased. So the steady climb in carbon dioxide is not just a change in composition — it is a driver of warming. …
Carbon dioxide is meteorologically a very important gas as it is transparent to the incoming solar radiation but opaque to the outgoing terrestrial radiation. It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth's surface, and is largely responsible for the greenhouse effect. The volume of other gases is constant, but the volume of carbon dioxide has been rising in the past few decades mainly because of the burning of fossil fuels -- this has also increased the temperature of the air. Ozone is another important component of the atmosphere, found between 10 and 50 km above the earth's surface; it acts as a fil …