Name: The Environment – Global Warming
Date of Issue: 30 June 2009
The global warming phenomenon has attracted increasing attention among large numbers of the general public in recent years. Global climate researchers have discovered that the earth's average temperature has risen by 0.75ºC over the course of the past century. There is some disagreement among researchers as to the causes of this phenomenon however, the view that mankind's activity has greatly contributed to accelerating global warming in recent years is widely accepted. The crux of the problem lies in the burning of fossil fuel materials, such as crude oil and coal, which emit greenhouse gases into the atmosphere, trapping heat close to the Earth.
This increased temperature causes weather changes and extreme weather throughout the world. Scientists point to phenomena such as glacial melting in the Polar Regions, continually increasing sea levels, consecutive years of drought and the outbreak of devastating storms. This phenomenon manifests in Israel in the form of decreasing annual rainfall, harm to water sources and the growth of desert areas in the country's southern region.
In an attempt to halt the global warming phenomenon, or at least slow its progress, researchers and entrepreneurs around the world are working diligently to develop alternative energy sources which will reduce the need to use fossil fuel, thus decreasing the greenhouse gases emitted into the atmosphere. Renewable and clean energy sources such as wind power, geothermal power and solar power are being especially emphasized.
Geothermal power plants utilize heat stored deep within the Earth as a power production source. Boiling water that either bursts out naturally from within the Earth (in the form of geysers) or that is drawn out via special drilling mechanisms is transferred to turbines that produce electricity.
The greatest potential for producing energy from natural sources lies in the utilization of the sun's rays. Israel is among the world's pioneers in this field. The solar heated water tank was developed in Israel in the 1950's and such tanks are currently used in most Israeli homes. Israeli companies have developed solar-thermal power stations that operate to effectively produce electricity at various locations around the world. Special effort has been made in recent years to develop inexpensive and effective technology that will enable the direct conversion of sunlight into electrical current through the use of photovoltaic cell panels. New regulations published recently in Israel encourage the installation of such systems in private homes and commercial facilities.
Denominations: (from right to left)
2.30 שח: Global Warming
The Earth is depicted as melting in a frying pan against a red background, in contrast to the tab featuring the international graphic symbols for alternative energy, ecology and the environment portrayed against a clean environment background.
2.30 שח: Solar Energy
A "green" house surrounded by green vegetation appears on the Earth; a photoelectric solar device is installed on the roof of the house. The tab features a photoelectric electricity production unit and a close-up photograph of solar cells.
2.30 שח: Geothermal Energy
The Earth is portrayed as a boiling kettle, illustrating the energy stored within the depths of the Earth. The tab features a photograph of a geyser with an adjacent turbine for the utilization of lost heat.
Friday, July 31, 2009