Greenhouse effectGlobal warming

Greenhouse effect and global warming

Carbon dioxide and water vapor are naturalcomponents of air. As such, they have generally not been considered pollutants. However, the voluminous amount of carbondioxide and water continously spewed intothe air by motor vehicles and factoriesworldwide has become alarming.

Greenhouse effect and global warming

Increased amounts of carbon dioxide and water vapor have possible long term effects.

The maxima of solar radiation which entersthe earth is in the shorter wavelenghtultraviolet and visible regions.

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The earth also radiates enrgy butitsmaxima is in the longer wavelenght

infrared region

Both carbon dioxide and water vapor molecules are not by affectedby incoming shorterwavelenght solar radiation but theyabsorb heat (infrared radiation) given off by the earth.

Greenhouse effect and global warming

This heat is released back to the loweratmosphere as their molecules vibrate.

This is called the greenhouse effect.

Both carbon dioxide and water vapor are called greenhouse gases.

Greenhouse effect and global warming

But there is less problem with water vaporbecause its concentration in air remains fairlyconstant. On the other hand, the amount of carbon dioxide in air has tremendouslyincreased in the past century because of man’s activities, mainly the burning of fossilfuels about 3 g of carbon dioxide is producefor every gram of fossil fuel burned.

Ozone depletion

Ozone Depletion

Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone over Earth's polar regions.

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The latter phenomenon is referred to as the ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar troposphericozone depletion events

Ozone Depletion

It is suspected that a variety of biological consequences such as increases in skin cancer, cataracts,[3] damage to plants, and reduction of plankton populations in the ocean's photic zone may result from the increased UV exposure due to ozone depletion.

Ozone Depletion