Action Research

Subject Science

 Class=10

Unit= 24

Topic=Atmosphere

Topic: Teaching Greenhouse Effect

Objective:

          At the end of the lesson teacher will be able in the following:

→→To define greenhouse effect

→→To understand about globalization

→→Effect of globalization

→→Preventive measures                  

Introduction of Greenhouse Effect:

The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.

Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.

Greenhouse Gases:

A greenhouse gases are those gases in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect.

                           Carbodioxide,Nitrousoxide,Methane,sulpherdioxide,Perflorocarbon, Hidroflorocarbon,Cloroflorocarbon ,watervapor are the gases which has covered  Troposphere and those gases does not let away the heat reflected from the Earth . In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects. Those gases greatly affect the temperature of the Earth; without them, Earth's surface would be on average about 39 °C colder than at present.

Global Warming:

Global warming is the rising average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's average surface temperature has increased by about 0.74˚ C Warming of the climate system is unequivocal, and scientists are more than 90% certain that most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and the burning of fossil fuels. These findings are recognized by the national science academies of all major industrialized Nations. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, and a probable expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, and sea ice. Other likely effects of the warming include more frequent occurrence of extreme-weather events including heat waves, droughts and heavy rainfall, species extinctions due to shifting temperature regimes, and changes in crop yields. Warming and related changes will vary from region to region around the globe, with projections being more robust in some areas than others. If global mean temperature increases to 4 °C (7.2 °F) above preindustrial levels, the limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world. Hence, the ecosystem services upon which human livelihoods depend would not be preserved.

Effect of Global warming:

The various effects of climate change pose risks that increase with global warming has organized many of these risks into five "reasons for concern:"

Threats to endangered species and unique systems

Damages from extreme climate events

Effects that fall most heavily on developing countries and the poor within countries

Global aggregate impacts

Large-scale high-impact events

The effects of global warming are the ecological and social changes caused by the rise in global temperatures. Evidence of climate change includes the instrumental temperature record, rising sea levels, and decreased snow cover in the Northern Hemisphere. Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in human greenhouse gas concentrations. Projections of future climate change suggest further global warming, sea level rise and an increase in the frequency of some extreme weather events. Parties to the United Nations Framework Convention on Climate Change (UNFCCC) have agreed to implement policies designed to reduce their emissions of greenhouse gases to avoid dangerous climate changes.

Resources:

               Internet and science book of class ten.

Procedure

Global warming is not only the problem of Nepal but it is universal problem. I studied nearly one month in related field. I got fully helped in school from co-workers. I found unsolved questions about creating by globalization such as the melting snow of Nepal, condition of the countries near by the ocean .Global warming causes many types of skin diseases. we have no way to fight with such types of diseases which are generating due to global warming .Nowadays we have to face dangerous natural disaster such as earthquake, tsunami thunderbolt, flooding .i talked  many  times  with my co-workers about the those related topics and  visited different websites in internet  .

Lesson learned:

               Deforestation, over population, industrialization are the main causes to increase greenhouse gases. Greenhouse gases absorb the heat from sunlight which results global warming. Environmental instability, different types of diseases and change in ecosystem are the main issues caused by global warming. On the other hand, there is not possibility of survival of plants and animal without greenhouse gases. it helps to maintain warm in the earth but it is not good if it exceeds its limitation.

Plan to Reduce Green House gases:

People are themselves responsible to grow the percentage of green house gases.  We are not much conscious about the natural disasters which are knocking us. We are too late, if we go further than this we will have no right to live in this beautiful world. If we are really conscious about the forthcoming result of the Earth, this is not so difficult to maintain the balance environments. We from our level   should start to love the nature then only nature favor us. Most industrialize countries should be more clear about it .Their industries will only remain when the world can exist in its status. Thus, who are producing green house gases should decrease the level.

·       Conclusion

As we know the world is losing its energy to hold the living beings and we people are the most responsible to push it in to the hell. We have to save it ourselves otherwise there is no way to live longer in this Earth. We are nowadays experiencing many types of natural disaster such as earthquake, tsunami, thunderbolt; flooding etc. and it will increase if we are not aware about it.