Atmospheric Heating Radiation Conduction Convection

Radiation The transfer of energy as electromagnetic waves The Earth receives energy from the sun by radiation Earth only receives about 2-billionths of the total energy given off by the sun

How is the sun’s energy used on Earth? Of the energy Earth receives from the sun’s radiation, approximately: – 19% is absorbed by ozone, clouds, and atmospheric gases – 51% is absorbed by the Earth’s surface – 26% is scattered and reflected by clouds and air – 4% is reflected by the Earth’s surface

Conduction The transfer of thermal energy through a material. Always transferred from warm to cold areas Must involve direct contact

Convection The transfer of thermal energy by the circulation or movement of a liquid or gas. Most thermal energy in the atmosphere is transferred by Convection Cycle of warm air rising in the Earth’s atmosphere is called a Convection Current

The Greenhouse Effect The process by which gases in the atmosphere, such as water vapor and carbon dioxide, absorb thermal energy and radiate it back to Earth. The atmosphere acts as a blanket – which allows solar radiation to enter the Earth’s atmosphere, but doesn’t allow it to escape.

Greenhouse - Radiation Balance In order for Earth to remain livable, the amount of energy received from the sun and the amount of energy returned to space must be approximately equal.

Global Warming An increase of greenhouse gases, causing the atmosphere to trap in more heat, causing a rise in Earth’s temperatures. Increased greenhouse gases, such as carbon dioxide, are caused by human activity such as burning fossil fuels and deforestation.