The 20th century was considered the hottest period since the last glaciation. 

There has been an average increase of 0.7 ° C in the last 100 years. For this reason, global warming is considered to be an urgent environmental problem with serious consequences for mankind.

Without it, the planet would be very cold, to the point that many life forms don´t exist.The problem is in the increase of emission of polluting gases, the so-called greenhouse gases. They accumulate in the atmosphere and with this, there is a greater retention of Earth's heat.

The greenhouse gases are:

·         Carbon Monoxide (CO);

·         Carbon Dioxide (CO2);

·         Chlorofluorocarbons (CFC);

·         Methane (CH4);

·         ...

There are several activities that emit these gases, the main ones are: 

·         Use of fossil fuels: The burning of fossil fuels used in cars driven by gasoline and diesel releases CO2, which is responsible for the retention of heat. 

·         Deforestation: In addition to destroying large areas of forest, deforestation also releases greenhouse gases. 

·         Burning: The burning of vegetation releases significant amounts of CO2. 

·         Industrial Activities: Industries that make use of fossil fuels are also responsible for the emission of polluting gases. This situation comprises most of the emission of greenhouse gases in developed countries. 

Global warming causes a series of changes on the planet, of which the main ones are: 

·         Change in the composition of fauna and flora throughout the planet. 

·         Defrost in great mass in the polar regions, causing the rise of the level of the sea.

·         Increased cases of natural disasters such as floods, storms and hurricanes.

·          Species extinction. 

·         Desertification of natural areas. 

·         Droughts may be more frequent.

·          Climate change may still affect food production, as many productive areas may be affected. 

Polar regions are the areas under the greatest pressure of global warming, due to the high temperatures worldwide. The melting of the polar ice caps is already a reality and the negative impacts in the region can already be observed. 

Animals living in these regions suffer from the consequences of global warming and many of them are at risk of extinction.