We explain what environmental impact is and what its causes and consequences are. Also, its characteristics and classification.
What is environmental impact?
Environmental impact is called immediate or medium or long term effect exerted by different human activities in the atmosphere. Environmental impact is a key concept for the conservation of the natural and human environment: through environmental impact assessment (EIA) of a given project, specialists can warn about its risks and convenience in environmental terms.
Some human activities, especially industrial activities, have a high environmental impactand cause significant alterations in ecosystems and humans.
The idea of environmental impact began to gain relevance in the mid-20th century as a consequence of the expansion of industrial activity after the Second World War and the identification of its environmental impacts starting in the 1970s.
Some of the most significant environmental impacts at that time were the loss of biodiversity and the extinction of species, the high levels of water and air pollution in some cities, and mainly the impact of atmospheric pollution from the publication of the first studies on climate change.
The environmental impact can be understood as negative when is detrimental to human life and the ecological balance of a region; and as positive when it helps restore that balance or reverses the damage caused to the environment.
Environment and nature. Although many times the concept of “environment” is directly associated with that of “nature”, it is important to keep in mind that the environment also includes human societies. For this reason, environmental impact studies do not only analyze the damage that can occur in ecosystems but also the alterations that can be generated in people’s quality of life.
Causes of environmental impact
The human actions that generate the greatest environmental impact are:
- Industry and energy production. Large-scale industrial production, especially in sectors such as the chemical, oil and manufacturing industries, generates atmospheric pollutants, toxic waste and intensive consumption of natural resources.
- Agriculture and intensive livestock. Intensive agriculture and livestock farming can cause soil degradation, loss of biodiversity and contamination of water and soil due to the excessive use of fertilizers and agrochemicals. In addition, livestock farming emits polluting gases such as methane and produces a large amount of waste.
- Deforestation. The clearing of native forests to free up land for agriculture or urban development is one of the main causes of biodiversity loss. Deforestation also affects soil water absorption and can worsen erosion and flooding.
- Infrastructure construction. The construction of roads, buildings, bridges and other infrastructure can involve the alteration of natural ecosystems, the fragmentation of habitats, the consumption of large quantities of materials and energy, and the generation of waste and waste.
- Transport. Fossil fuel vehicles such as cars, trucks, boats and airplanes emit large amounts of greenhouse gases and other air pollutants.
- Mining. The extraction of minerals and metals can have significant impacts on the environment, such as soil degradation, water pollution and loss of biodiversity. Additionally, large-scale mining can generate a large amount of waste and consume large amounts of water. This impacts both the ecosystems and the quality of life of the people who live near the mining ventures.
Types of environmental impact
Depending on their nature and duration, environmental impacts can be classified into:
- Direct or indirect impacts. Direct impacts are those that cause immediate and perceptible short-term changes in the environment, while those that are generated later are called indirect.
- Temporary or permanent impacts. They are those that appear while a certain activity is happening but disappear when the activity stops. Permanent impacts are those impacts that continue to be present even after the activity that generated them has ended.
- Reversible or irreversible impacts. They are those that can be repaired, either by nature itself or by human actions, to restore the damage caused. Irreversible impacts cannot be repaired by nature or by humans.
- Cumulative or synergistic impacts. Cumulative impacts are those that worsen over time, while synergistic impacts are those in which different impacts are related and produce greater damage as a consequence of that combination.
- Current or potential impacts. Current impacts are those that occur during the activity that generates them, while potential impacts are those that could occur in the future if adequate preventive measures are not taken.
- Local or widespread impacts. Local impacts are those that occur in a specific location, while disseminated impacts can affect ecosystems and environments far from the place where the impact occurs.
- Accidental or planned impacts. Environmental impacts are sometimes planned in advance, as in the case of the construction of a dam, in which it is known that a certain area is going to be flooded and the necessary measures are taken to ensure that the impact is as minor as possible. Other times, impacts occur accidentally and are more difficult to foresee and prevent.
Consequences of environmental impact
The most important consequences of the environmental impact of human activities are:
- The loss of biodiversity. The extinction of animal species and the deforestation of native forests are one of the main consequences of the environmental impact of human activities. The degradation of ecosystems has harmful effects not only on the natural environment, but also on people’s quality of life.
- Soil degradation. The intensive use of land for livestock farming and agriculture degrades the soil, which reduces its fertility and productivity. This has an impact on the deterioration of soil quality and a decrease in food production.
- pollution. The emission of polluting gases into the atmosphere and toxic substances into soil and water produces a significant environmental impact. Air pollution is considered the main cause of climate change, and water and soil pollution reduces the quality of life of millions of people who need these resources to live.
- The impacts on human health. Pollution of air, soil and water has negative effects on human health. People get sick from being exposed to air pollution, from consuming unsafe water or from eating products contaminated with chemicals or substances toxic to their health.
Environmental Impact Assessment (EIA)
The environmental impact assessment (EIA) is the technical study that must be carried out by any company that wants to propose carrying out an activity in a certain place. It is a study that must contain the prediction, identification, assessment and management of the environmental and social impacts that the project could generate. Its main purpose is to prevent or correct the consequences or adverse effects of the project and enhance its beneficial effects.
Once presented the environmental impact assessmentthe local authorities must approve it to authorize the activity to be carried out. If they consider that the risks are high or that the actions to correct or prevent damage are not correct, the authorities may reject the evaluation and not authorize the project.
The environmental authorities are also responsible for sanctioning and fining those activities that do not comply with what was proposed in the environmental impact assessment or that have generated damage that was later not correctly repaired or reversed.
Examples of environmental impact
Some of the constructions that produced the greatest environmental impact are:
- The Three Gorges Dam (China). It is one of the largest dams in the world. Its construction, on the Yangtze River, had a very significant impact on the diversity of the basin and caused the displacement of more than 1,200,000 people as a result of the flooding of extensive agricultural and urban areas.
- The trans-Amazonian route (Brazil). Almost 5,000 kilometers long, its construction led to the deforestation of extensive areas of the Amazon rainforest.
- Kansai airport (Japan). This airport was built on an artificial island in Osaka Bay. The construction of the island impacted the marine ecosystems of the area, affected the populations of migratory birds and caused the loss of coastal habitats.
References
- Fernández, A. (sf). Environmental impact. https://www.todamateria.com/
- Reinoso, L. (2013). Criteria for the preparation of environmental impact studies. Secretariat of Environment and Sustainable Development of the Nation.
- Ropero Portillo, S. (2020). Types of environmental impacts. https://www.ecologiaverde.com/
