Answer:
The presence of smog in the atmosphere and exploitation and burning of coal
Step-by-step explanation:
The "smog" can be observed as dark low clouds in the cities. These are formed by accumulation of gases such as: CO2, soot, smoke and dust in suspension. If the atmospheric concentration of the main gases responsible for the greenhouse effect that was maintained in 2016 is maintained, the average temperature of the Earth will have risen 1, 3 ° C in 2020 and 3 ° C in 2070.
In the process of using coal, important environmental damage occurs because when burning it releases large amounts of greenhouse gases.
The damage caused by coal combustion is much greater when poor quality fuel is used, because the impurities it contains are converted into sulfur oxides and other toxic gases.
In the production of electricity, about 5 tons per year are used, causing havoc in terms of pollution