Objectives After this lesson, students should be able to: Define the term greenhouse effect. Explain the mechanisms of greenhouse effect. Explain what are the effects of global warming on Earth and its inhabitant. State and discuss the problems that would be brought up by global warming. Discuss the solutions to prevent global warming.
What is “Greenhouse effect”? The Greenhouse effect is caused by an atmosphere containing gases that absorb and emit infrared radiation.
Greenhouse gases trap heat within the surface-troposphere system, causing heating at the surface of the Earth.
Mechanisms of Greenhouse effect
Mechanisms of Greenhouse effect Sunlight brings energy into the climate system; most of it is absorbed by the oceans and land. 1 THE GREENHOUSE EFFECT: Heat (infrared energy) radiates outward from the warmed surface of the Earth. Some of the infrared energy is absorbed by greenhouse gases in the atmosphere, which re-emit the energy in all directions. 2 3
Mechanisms of Greenhouse effect Some of the infrared energy further warms the Earth. Some of the infrared energy is emitted into space. 4 5
Mechanisms of Amplified Greenhouse effect AMPLIFIED GREENHOUSE EFFECT: Higher concentrations of CO2 and other "greenhouse" gases trap more infrared energy in the atmosphere than occurs naturally. The additional heat further warms the atmosphere and Earth’s surface. Sunlight brings energy into the climate system; most of it is absorbed by the oceans and land. 6 1
Greenhouse gases Major greenhouse gases are: Water vapour Carbon dioxide Methane Nitrous oxide Ozone Chloroflurocarbon (CFC)
Causes of Global Warming These are the major causes of global warming: Volcanic eruption Solar and orbital variations. Human activities (due to the increasing human population) Burning of fossil fuel. Clearing of rainforest.
Problems caused by global warming Increase in global temperature. Melting of ice in Polar Regions. Rising of sea level. Increase in extreme weather events. Mass extinction of flora and fauna species.