What is global warming?

Our planet, since its formation, has never had a uniform climate. The temperature changes have been caused by natural phenomena such as tides, the season of the year and volcanic eruptions, and variations in the layers of air.
The greater temperature variations they have been between the ice ages and periods of global heat. These oscillations have happened throughout the life of the planet. To determine when and how they occurred, studies have been made of the ice sheets and tree rings, which have made it possible to establish with some precision when they occurred. These processes are called climate change.
However, scientists who have studied it, discovered that the Middle Ages was a warm period, lowering the temperature around the sixteenth and seventeenth centuries, and that from that moment the temperature has risen again with much speed.
The Industrial Revolution in the eighteenth century, brought the massive use of coal, had as by-products the emission into the atmosphere of solid microparticles, gases and heat; As industrialization generalized, the need for greater sources of energy was filled using fossil fuels, derived from petroleum.

Many scientists have linked the action of man since the industrial era and its emissions of heat and pollutants, with the acceleration of the natural process of global warming or global warming. The combination of the heat emitted with the polluting gases and solids that act as filters or barriers for the diffusion of heat and humidity, combined with the natural effect of the ozone layer and solar radiation, form what is called the greenhouse effect, since heat or low temperature seem to be enclosed within these layers, as happens with the climate of a greenhouse.