Environmental Challenges: Soil Loss and Climate Change

Loss of Fertile Soil and Intensive Agriculture

Loss of fertile soil: Intensive agriculture, characterized by the use of heavy machinery and the abuse of monocultures, causes the deterioration and impoverishment of the soil. The increasing use of fertilizers can pollute groundwater. The number of heads of livestock per hectare of pasture is limited by soil characteristics; an excess causes degradation similar to intensive agriculture.

The most important factor is the loss of soil through water erosion. Climate change is altering the global climate of the earth, producing abnormal variations in temperature, rainfall, and wind, changing their frequency and intensity.

The Greenhouse Effect and Global Warming

Carbon dioxide and other gases in the atmosphere, such as water vapor, cause the greenhouse effect. This involves the absorption of infrared radiation, preventing some from escaping the earth, which causes the surface temperature to increase. The problem today is the release of gases produced by the overheating of the planet. Many scientists believe that climate change does not represent a danger to life itself, because life in general can adapt as it has in the past, but it represents a socioeconomic disaster.

Causes of Climate Change

Natural Sources

• Respiration: All living beings expel carbon dioxide.
• Decomposition: The natural process of organic matter breaking down.
• Volcanic eruptions: Volcanoes emit large amounts of carbon dioxide.

Anthropogenic Sources

• Combustion of fossil fuels: The burning of coal, gas, and petroleum.
• Deforestation: The reduction of forest areas affects the equilibrium concentration of carbon dioxide. This is caused by the burning of vegetation and the release of stored gas; without trees, photosynthesis cannot occur.

Environmental Effects of Climate Change

The effects include sea level rise, decreased rainfall (making it difficult to replenish water supplies), the extension of tropical diseases, and coral bleaching (the death of the coral white).

Global Agreements and Necessary Changes

The Kyoto Protocol and the UNFCCC (United Nations) agree to:

• Reduce CO2 emissions by 2020 between 25% and 40% over 1990 levels.
• Provide funding to invest in technology for emerging countries to mitigate climate change and adapt.
• Funding to tackle natural disasters.
• Money to preserve and protect forests and jungles.
• Reduce carbon dioxide emissions from deforestation, which are responsible for 20% of greenhouse gases.

The Ozone Layer and Ultraviolet Radiation

Between 20 and 40 km, the ozone layer (or ozonosphere) absorbs much of the sun's ultraviolet radiation. Chlorofluorocarbons (CFCs) are molecules containing carbon, chlorine, and fluorine that alter the natural cycle of ozone. Chlorine is very reactive and combines with ozone: Cl + O3 → ClO + O2 and ClO + O → Cl + O2.

Consequences of Ozone Depletion

With this depletion, there is an increase in ultraviolet radiation incident on the surface of the earth, which can cause alterations in genetic material. It affects microorganisms and some plants, reduces the efficiency of the immune system, increases eye injuries, and causes various types of skin cancer.