GreenHouse Effect and Global Warming
A greenhouse is a structure with walls and roof made mainly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown.
A more scientific definition is a covered structure that protects the plants from extensive external climate conditions and diseases, creates optimal growth microenvironment, and offers a flexible solution for sustainable and efficient year-round cultivation.
What Are Contemporary Issues? General Overview
A greenhouse is a structure with walls and roof made mainly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown.
A more scientific definition is a covered structure that protects the plants from extensive external climate conditions and diseases, creates optimal growth microenvironment, and offers a flexible solution for sustainable and efficient year-round cultivation.
A modern greenhouse operates as a system; therefore it is also referred to as controlled environment agriculture (CEA), controlled environment plant production system (CEPPS), or phytomation system.
Many commercial glass greenhouses or hothouses are high tech production facilities for vegetables or flowers.
The glass greenhouses are filled with equipment including screening installations, heating, cooling, lighting, and may be controlled by a computer to optimize conditions for plant growth.
GreenHouse Gases
These are trace gases that partially absorbed the emitted long wave terrestrial radiation in the atmosphere.
The major greenhouse gases emitted into the atmosphere are carbon dioxide, methane, nitrous oxide, and fluorinated gases. Some of these gases are produced almost entirely by human activities; others come from a combination of natural sources and human activities.
The World Meteorological Organization (WMO) describes the build-up of greenhouse gases in the atmosphere during the 20th century as resulting .from the growing use of energy and expansion of the global economy.
According to the WMO, the build-up of greenhouse gases in the atmosphere alters the radiative balance of the atmosphere. The net effect is to warm the Earth‘s surface and the lower atmosphere because greenhouse gases absorb some of the Earth‘s outgoing heat radiation and reradiate it back towards the surface
Many of the major greenhouse gases can remain in the atmosphere for tens to thousands of years after being released.
They become globally mixed in the lower part of the atmosphere, called the troposphere (the first several miles above the Earth‘s surface), reflecting the combined contributions of emissions sources worldwide from the past and present.
Due to this global mixing, the impact of emissions of these gases does not depend on where in the world they are emitted. Also, concentrations of these gases are similar regardless of where they are measured, as long as the measurement is far from any large sources or sinks of that gas.
Several factors determine how strongly a particular greenhouse gas affects the Earth‘s climate. One factor is the length of time that the gas remains in the atmosphere. A second factor is each gas‘s unique ability to absorb energy.
By considering both of these factors, scientists calculate a gas‘s global warming potential, which measures how much a given amount of the greenhouse gas is estimated to contribute to global warming over a specific period of time (for example, 100 years) after being emitted.
Greenhouse Effect
Greenhouse effect can be defined as the exchange of incoming and outgoing radiation that warms the earth.
The greenhouse effect occurs when solar energy making contact with the earth‘s surface is retransmitted to the atmosphere in the form of infrared thermal radiation. This radiation has a lower wave frequency than solar energy itself.
GHG molecules absorb this thermal radiation at low frequencies, causing these molecules to vibrate.
These greenhouse molecules then emit energy in the form of infrared photons, many of which return to the earth‘s surface. Non-GHGs such as oxygen and nitrogen do not absorb thermal radiation.
The greenhouse effect is measured in terms of Radioactive Forcing (RF) in units of watts per square meter (W/m2). Since the Industrial Revolution, the total RF is estimated to have increased by approximately 2.3 W/m2 (1.1 W/m2 – 3.3 W/m2; 90% confidence interval) mainly due to the net effect of increased GHG and aerosol concentrations in the atmosphere.
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Shortwave radiation passes through the atmosphere, whereas long wave terrestrial radiation emitted by the warm surface of the earth is being partially absorbed by a number of trace gases in the atmosphere.
Thus the greenhouse effect arises because the atmosphere is largely transparent to incoming solar radiation, while being quite heavily absorbing to outgoing thermal radiation from the planetary surface and the atmosphere.
Since the beginning of the earth origin, the effect exists as a natural process. But since the 20th century the effect is enhanced by man‘s activities that are liable to destabilizes the natural balance.
Greenhouse gases do not interfere to any great extent with the incoming solar energy. But once that energy reaches the Earth’s surface, it is absorbed, warms the land and ocean surface of the planet, and then is re- emitted.
The amount of heat re-emitted and eventually lost to space must equal the amount gained from the Sun if the temperature of the planet is to remain constant.
But the so-called terrestrial energy stream is different in character it is longer in wavelength than the incoming solar energy as the Earth is cooler than the Sun and the greenhouse gases interfere with it strongly before it can escape to space.
The greenhouse gases absorb the outgoing terrestrial energy, trapping it near the Earth’s surface, and causing even more warming. This is the “greenhouse effect”. Without it the planet would be too cold to support life as we know it.
Unfortunately, humanity, through energy generation, changing land use and other processes, has produced a substantial increase in the amount of greenhouse gases in the atmosphere, enhancing the natural greenhouse effect, and it is feared that this continuing change will lead to a major shift in global climate.
In summary, these are trace gases that partially absorbed the emitted long wave terrestrial radiation in the atmosphere.
The major greenhouse gases emitted into the atmosphere are carbon dioxide, methane, nitrous oxide, and fluorinated gases. Some of these gases are produced almost entirely by human activities; others come from a combination of natural sources and human activities.
A greenhouse is a structure with walls and roof made mainly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown. A more scientific definition is a covered structure that protects the plants from extensive external climate conditions and diseases.
Global warming as a contemporary issue has made the concept of greenhouse more relevant.
Green house is more scientifically defined as a covered structure that protects the plants from extensive external climate conditions and diseases, creates optimal growth microenvironment, and offers a flexible solution for sustainable and efficient year-round cultivation.
A modern greenhouse operates as a system; therefore it is also referred to as controlled environment agriculture (CEA), controlled environment plant production system (CEPPS), or phytomation system.
Many commercial glass greenhouses or hothouses are high tech production facilities for vegetables or flowers. Greenhouse effect can be defined as the exchange of incoming and outgoing radiation that warms the earth.
The greenhouse gases absorb the outgoing terrestrial energy, trapping it near the Earth’s surface, and causing even more warming. This is the “greenhouse effect”. Without it the planet would be too cold to support life as we know it.
Unfortunately, humanity, through energy generation, changing land use and other processes, has produced a substantial increase in the amount of greenhouse gases in the atmosphere, enhancing the natural greenhouse effect, and it is feared that this continuing change will lead to a major shift in global climate.
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