Atmospheric Pollution and Environmental Degradation: Causes and Effects

Atmospheric Pollution

The combustion of hydrocarbons, largely due to industrial processes or transportation, generates smoke, suspended particulates, and gaseous pollutants. The most common are carbon monoxide, carbon dioxide, sulfur oxides, nitrogen oxides, and hydrogen sulfide.

Industrial facilities and power plants usually emit a greater volume of contaminants. In the developed world, the danger of some issues has forced the relocation of industries to industrial belts outside of densely populated urban areas. However, emissions are still causing serious environmental problems.

Acid Rain and Smog

Emissions of sulfur and nitrogen react in the atmosphere when in contact with oxygen, water vapor, and light, producing mainly sulfuric acid and nitric acid. These elements move through the atmosphere and fall as acid rain or dry deposition of particles.

The main source of pollutants affecting the acidification of rain is the burning of fossil fuels such as coal or fuel oil. The main problems caused by this phenomenon are:

• Acidification of the soil, damaging vegetation and agriculture in general
• Destruction of leaves and other aerial organs of plants
• Water acidification of lakes and streams, which affects wildlife very negatively
• Corrosion of buildings, monuments, and structures in general

Another problem of air pollution, focused on large cities, is smog. Over time, coal was replaced by petroleum, generating photochemical smog, which occurs mainly in big cities with a large number of vehicles.

This type of smog is formed from the reaction of light on nitrogen oxides, oxygen, and other combustion gases, causing the formation of oxidizing pollutants, including ozone. Ozone is the main component of photochemical smog and is harmful at low altitudes.

Ozone Depletion

Ozone gas is mostly concentrated in the boundary between the stratosphere and ionosphere. There, a layer receives the effects of radiation and dissociates into oxygen (O) atoms that group to form ozone. When ozone receives radiation, it dissociates and forms again, maintaining a balance between O and ozone. The ozone layer acts as a sunscreen.

The presence of chlorofluorocarbons (CFCs), used in aerosols, refrigeration, and air conditioning, releases compounds into the atmosphere. After eight years, these compounds reach the stratosphere, as they are stable and can last for about 100 years.

The weakening of the ozone layer can cause an increase in ultraviolet radiation. In 1992, at the Rio Summit, a number of states pledged to reduce emissions of CFCs. Substitutes for CFCs include butane and propane.

Deforestation and Biodiversity Loss

One of the most important causes of deforestation is due to clearing, logging, and burning forests.

Forest clearing is a land operation to till the land for the first time in order to cultivate it. Based on vegetation types and farming, clearing can be done through mowing, burning of vegetation, or tree felling. To achieve clearance of hardwoods, forests are burned, increasing greenhouse gases released into the atmosphere by 15%. There is a decline in biodiversity due to deforestation, desertification, increased pollution, and uncontrolled hunting and fishing.

Erosion and Desertification

Soil erosion is the natural process of its destruction. Several causes include:

• Drought
• Heavy rains causing flooding and soil movement
• Deforestation
• Changes caused by intensive farming
• Introduction of machinery

Monoculture is the practice of planting only one type of crop in large areas. It allows farmers to increase production and dependence.

Desertification is the process of transforming terrain into a desert due to anthropogenic causes. It occurs due to human actions, which were previously only in deforested and eroded areas.

Consequences of desertification include an increased frequency of dust and sand storms and floods. This phenomenon causes the migration of a large volume of people into fertile areas, often the suburbs of large cities.

Solutions to curb desertification (the process of transforming terrain into a desert due to natural causes) include:

• Restocking forests and marginal lands
• Protecting slopes with small retaining walls
• Conserving vegetation at the headwaters of rivers
• Avoiding overgrazing
• Using techniques that allow agriculture to conserve soil quality