The The greenhouse greenhouse

effecteffect

The Greenhouse Effect is a natural process The Greenhouse Effect is a natural process in which heat from the sun is held by the in which heat from the sun is held by the Earth's atmosphere near the Earth's Earth's atmosphere near the Earth's surface, providing enough warmth to surface, providing enough warmth to support life.support life.

Without this effect, it is estimated that the Without this effect, it is estimated that the average temperature of the Earth would be average temperature of the Earth would be about - 18°C, the temperature of a Russian about - 18°C, the temperature of a Russian winter, and unsuitable for life.winter, and unsuitable for life.

The current temperature is about 15°C. The current temperature is about 15°C.

The Greenhouse Effect The Greenhouse Effect was identified by Joseph was identified by Joseph Fourier in 1824 and first Fourier in 1824 and first investigated by Svante investigated by Svante Arrhenius in 1896. He Arrhenius in 1896. He observed that when the observed that when the industrial revolution industrial revolution began, more carbon began, more carbon dioxide was being dioxide was being released into the released into the atmosphere. atmosphere.

He was the first to He was the first to understand that this understand that this increase meant a rise in increase meant a rise in the temperature of the the temperature of the earth.  earth. 

Svante Arrhenius

The process known as the Greenhouse Effect The process known as the Greenhouse Effect works in the following way. As energy from the works in the following way. As energy from the Sun passes through the atmosphere a number of Sun passes through the atmosphere a number of things take place:things take place:

• some of the energy is reflected back to space by some of the energy is reflected back to space by clouds and other atmospheric particlesclouds and other atmospheric particles

• a portion of the energy is absorbed by clouds, a portion of the energy is absorbed by clouds, gases, and particles in the atmosphere.gases, and particles in the atmosphere.

• of the remaining solar energy passing through the of the remaining solar energy passing through the Earth's atmosphere, a little is reflected from the Earth's atmosphere, a little is reflected from the surface back to space.surface back to space.

On average, about 50% of the Sun's radiation reaches the On average, about 50% of the Sun's radiation reaches the surface. This energy is then used in a number of surface. This energy is then used in a number of processes, including the heating of the ground surface; the processes, including the heating of the ground surface; the melting of ice and snow and the evaporation of water; and melting of ice and snow and the evaporation of water; and plant photosynthesis.plant photosynthesis.

Infrared radiation is emitted by the Earth's surface. As it Infrared radiation is emitted by the Earth's surface. As it moves up through the layers of the atmosphere, the moves up through the layers of the atmosphere, the molecules of carbon dioxide, water vapour or some other molecules of carbon dioxide, water vapour or some other greenhouse gas in each layer absorb some of the energy.greenhouse gas in each layer absorb some of the energy.

Some of the absorbed energy is radiated back toward the Some of the absorbed energy is radiated back toward the ground, and some upwards to higher layers. Eventually, ground, and some upwards to higher layers. Eventually, the energy reaches a layer so thin that radiation can the energy reaches a layer so thin that radiation can escape into space.escape into space.

Air Air pollutionpollution

Air pollution is the introductino of chemical, Air pollution is the introductino of chemical, particulate matter, or biological materials that particulate matter, or biological materials that cause harm of discomfort to humans or other living cause harm of discomfort to humans or other living organisms, or cause damage to the natural organisms, or cause damage to the natural enviroment or built enviroment, into the enviroment or built enviroment, into the atmosphere.atmosphere.

Pollutans can be in the form of solid particles, Pollutans can be in the form of solid particles, liquid droples, or gases. In addition they may be liquid droples, or gases. In addition they may be natural or man-made.natural or man-made.

Pollutans are classified in primary and secondary:Pollutans are classified in primary and secondary:

• primary pollutans are directly emitted from a primary pollutans are directly emitted from a process, such as ash from volcanic eruption, the process, such as ash from volcanic eruption, the carbon monoxidegas from a motor vehicle exhaust carbon monoxidegas from a motor vehicle exhaust or solfur dioxide released from factories.or solfur dioxide released from factories.

• secondary pollutans are not emitted directly. They secondary pollutans are not emitted directly. They form in the air when primary pollutans react or form in the air when primary pollutans react or interact. An example is ground level ozone, tha interact. An example is ground level ozone, tha make up photochemical smog.make up photochemical smog.

Acid rainAcid rain Acid rain is a rain or any other form

of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of carbon dioxide, sulfur dioxide and nitrogen oxides which react with the water molecules in the atmosphere to produce acids. Nitrogen oxides can also be produced naturally by lightning strikes and sulfur dioxide is produced by volcanic eruptions.

Effects Effects Acid rain has been Acid rain has been

shown to have shown to have adverse impacts on adverse impacts on forests, freshwaters forests, freshwaters and soils, killing insect and soils, killing insect and aquatic life-forms and aquatic life-forms as well as causing as well as causing damage to buildings damage to buildings and having impacts and having impacts on human health. on human health.

Health effectsHealth effects Air pollution is a significant risk factor for multiple Air pollution is a significant risk factor for multiple

health conditions including respiratory infections, health conditions including respiratory infections, heart disease and lung cancer. The healt effects heart disease and lung cancer. The healt effects caused by air pollution include difficulty in caused by air pollution include difficulty in breathing, wheezing, coughing and aggravation of breathing, wheezing, coughing and aggravation of existing respiratory and cardiac conditions.existing respiratory and cardiac conditions.

Individual reactions to air pollutant depend on the Individual reactions to air pollutant depend on the

type of pollutant a person is exposed to, the type of pollutant a person is exposed to, the degree of exposure, the individual’s health status degree of exposure, the individual’s health status and genetics.and genetics.