Green house

The greenhouse effect refers to circumstances where the short wavelengths of visibleLight from the sun pass through a transparent medium ( i.e. envelope of gases CO, CO2, SO2, etc . )and are absorbed , but the longer wavelength of the infrared re - radiation from the heated objects are unable to pass through that medium and are trapped causing more heating and a higher resultant temperature.

Greenhouse gas levels have been increasing since the start of the Industrial Revolution. The most contributing greenhouse gases are carbon dioxide, nitrous oxide and methane. But without some greenhouse gases and the greenhouse effect, earth's temperature would be close to -18°C.

Causes

The population of the world is increasing day by day. The population of the world in increasing at the rate of three children per second. The pollution of the world is also increasing. The amount of smoke, dust and greenhouse gases like CO2, N2O, CH4, H2O vapour etc are increasing in the atmosphere as they are produced by industries and vehicles.

These gases allow the solar radiation of the short wavelength to escape out from the earth but prevent the solar radiation of the longer wavelength to escape out from the earth. Asa result, this radiation, and various gases are stored in the atmosphere of earth and increase the temperature of the earth.Industries which are involved in cement production,fertilisers, coal mining, etc produce harmful greenhouse gas.Nitrous oxide is one of the greenhouse gas that is used in fertiliser and contributes to the greenhouse effect.

Effects of Green House

The effects of greenhouse on environment are as follows:

1. Greenhouse effects increase the temperature of the earth causing global warming. Global warming effects the environment in various ways like desertification, increases snow melting, increases in sea level and stronger storms and extreme events.
2. Snow melting in the mountains causes flooding during monsoon.
3. An increase in the temperature of the earth causes hurricanes and cyclones in the ocean and seas.
4. As the temperature of the earth increases, it increases the evaporation of water from the farms, sea, lakes and ponds that result in the decrease of crop yield, and causes drought.
5. Greenhouse also affects the climatic balance. Monsoon may even stop altogether or rainfall may be altered.
6. As nitrous oxide is a greenhouse gas, It damages the ozone layer and cause ozone layer depletion.
7. It imbalances the ecosystem.
8. As northern countries get warm due to the greenhouse effect, disease carrying insects migrate north, bringing plague and disease with them.

Artificial Green House

An artificial greenhouse is a man-made greenhouse. It is a house made of glass or plastic on a metallic frame. It is mainly used to grow offseason plants. In the artificial greenhouse, the glass and plastic allow the only short wave to pass but do not allow longer waves to pass. Here, the glass changes short wave into infrared radiation.

The infrared radiation so formed do not escape out through the greenhouse and the temperature inside it increases. In the artificial greenhouse, the artificial temperature is provided to grow the plants. Here, the favourable condition necessary for the growth of plants is provided like climate, light, soil, moisture and other essential conditions. The roof of the artificial greenhouse is made slanted so that maximum solar energy enter through it.

Importance of artificial greenhouse are as follows:

• Offseason plants can be grown in all twelve months.
• Plants can be grown in cold countries where there is less temperature by using the artificial greenhouse.
• Various types of flower,crops, vegetables and fruits can be grown by this methods.
• Plants grown by using this method can reduce environment pollution.

Control measures for greenhouse effect:

• The use of materials should be minimized that produce greenhouse gases.
• The burning of fossil fuel and home residue should be stopped.
• Afforestation should be done.
• Alternative sources of energy should be used.
• We should use eco- friendly material
• Incineration plant should be established.
• Pollution should be controlled.

Climate Change

Human activity that changes climate

The climate of the earth has changed from past few years. According to an ongoing temperature analysis conducted by scientists at NASA's Goddard Institute for Space Studies (GISS), the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880 . The major problem of the world is global warming . It is the proof of climate change. Climate change is the change in weather condition. Many countries have face changes in the climatic condition like changes in rainfall, resulting in more floods, droughts, or intense rain, as well as more frequent and severe heat waves. The ocean and glaciers have also faced the effects of climate change like oceans are warming and becoming more acidic, ice caps are melting, and sea levels are rising.

Though Nepal is a small country, it is rich in natural resources. The topographical structure of Nepal is different in different parts. Nepal is divided into 3 regions, Mountain region, Hill region and the Terai region. The climate of mountain region is cold and terai region is hot. There is variation in a climate of Nepal in different parts. Nepal is also one the country that is facing huge effects of climate change. The climatic condition of Nepal is not as it was before 5 or 10 years.

Causes of Climate Change are as follows:

1. Increase in temperature: Due to the global warming and greenhouse effect, the temperature of the earth is increasing day by day. Some parts of the earth are getting very cold and some parts are getting very hot. The temperature of the earth has increased by 1.5o F over the past century and is expected to rise by 0.5 to 8.6o F over next hundred year.
2. Release of the greenhouse effect: During the burning of fuel like coal, petroleum, etc, a large amount of carbon dioxide is produced which affects the environment resulting in the climate change. Similarly, various types of harmful gases that come out from the industries also affect the environment and atmosphere. Gases like nitrous oxide, methane etc also result in climate change.
3. Deforestation: As the population of the world is increasing day by day, people need more house, clothes, furniture etc for which trees are cut down. People of village depend on upon wood for fuel. So they cut down trees illegally. As we know that, trees take carbon dioxide, if there are no trees than the amount of carbon dioxide increases on earth. As a result, this affects the environment and bring climate change.
4. Increase in the use of chemical fertilizers: To fulfill the need and demand of increasing population, people use various types of fertilizer to for more production of foods and crops. This fertilizer affects the land as well as produces greenhouse gases. It affects the various sources of water with which it mixes with. It imbalance the aquatic ecosystem as well as it brings climate change by producing harmful gases.
5. Industrialization: There are many industries in the world. These industries produce various types of harmful gases like carbon dioxide and sulphur dioxide, dirt and dust, and waste liquid with harmful chemicals. It causes acidic rain and increases greenhouse gases.
6. Volcanic eruption: When there is volcano eruption, various types of harmful gas and dirt comes out from the earth in a large amount. It forms huge fog and cloud with harmful gases. It blocks the sunlight coming into the earth's surface. As a result, the places near it becomes colder and colder due to lack of sunlight heat and changes the climate.

Effects of climate change are listed in points:

1. Change in air temperature: The temperature of the earth has increased by 1.5o F over the past century and is expected to rise by 0.5 to 8.6o F over next hundred year. This is due to the climate change.
2. Impact on biodiversity and ecosystem: Different plants and animals are unable to change themselves according to the changing climate. Their population are decreasing and are near to extinct.
3. Impact on human health: As the temperature of the earth is increasing day by day, the disease transfer very faster. People suffer from various diseases due to warm air, hot land etc. It decreases the energy of human and people suffer from various types of disease.
4. Impact on agriculture: Change in climate causes the greenhouse effect, untimely rainfall, drought, scarcity of water, drying out of various sources of water causing the agriculture. People of Nepal depend on rainwater for agriculture. Untimely rainfall causes flood, landslide etc in the hilly region.
5. Negative effect on water resources: Climate changes largely effects on water resources. Drying out of some sources of water is due to the climate change. Due to climate change, there is less snowfall but more melting of snow. These causes flooding due to over melting of snow. Sometimes, the river gets small and sometimes it gets big. It also causes glacier lake outburst due to increasing in temperature. It also affects the water cycle.
6. Energy crisis: Rivers and other sources of water are used for hydropower generation. When there are increase and decrease in the amount of water then the power generated also become sometimes less and more. Due to which, the country fails to fulfill the required amount of energy. This causes the energy crisis.
7. Impact on a human settlement: Climate change affects the human civilization near mountain, river, sea and lakes. Like when river sunkoshi was blocked, many houses of Sindhupalchowk were affected, and many people were replaced during flooding in Koshi river.
8. Impact on physical facilities: Climate change affects the developmental activities like construction of the road, bridge, dam, etc. as it causes sudden rainfall resulting in flooding and landslide.

Solution for Climate Change:

There are various ways to solve climate problem which are listed below,

1. Afforestation should be done.
2. Public awareness should be created about effects of climate change.
3. Burning of fuel should be stopped.
4. Alternative sources of energy should be used.
5. Pollution form industries and factories should be minimized.
6. Natural resources should be preserved.
7. Sustainable developmental activities should be done.
8. Chemical fertilizers should be not used.
9. Pollution should be controlled.