There is much evidence that the greenhouse effect has been causing an increase in the average temperature of the Earth. This phenomenon is called global warming .
Causes of global warming
The burning of mineral coal and petroleum-based fuels to generate energy, since the Industrial Revolution, has released several gases into the atmosphere, such as carbon dioxide, whose concentration in the atmosphere has increased considerably in recent decades.
Our atmosphere is composed of gases that retain heat. These gases are called greenhouse gases. Therefore, the increase of these gases in the atmosphere could cause an increase in the temperature of the planet as a result of the intensification of the greenhouse effect.
Thus, the increase in the amount of carbon dioxide in the atmosphere, released by industries and by burning , is possibly one of the factors responsible for the intensification of the greenhouse effect.
The felling of large areas of forest also contributes to the increase in the concentration of carbon dioxide in the atmosphere, since the presence of vegetation implies greater absorption of carbon dioxide, since the plants use this gas in photosynthesis .
Another important greenhouse gas is methane, produced in the decomposition of organic waste and in the digestion of food in the digestive system of cattle and goats.
Consequences of global warming
The increase in temperature can cause the sea level to rise because of the thermal expansion of the water (hot water occupies more volume than cold water) and the melting of part of the polar ice caps.
Some estimates indicate an increase of 1.4 ° C to 5.8 ° C in 100 years (the average global warming during the 20th century was just over 0.5 ° C), with an increase in sea level of 88 cm in the end of that period.
With this increase, large areas of the coast would be flooded, many islands would be submerged and many people would be homeless. In addition, the advancement of salt water can contaminate freshwater reservoirs closest to coastal regions.
The warming of the planet may also interfere in the pathways of air and water currents and change the rain regime and the climate of several regions, harming agriculture. Another negative factor would be the proliferation of insects (which reproduce better in warmer climates) that transmit pathogenic microorganisms and that attack plantations.
Some studies indicate that developing countries will be badly hit by global warming, with a 25% drop in food production by 2080 (although some crops may benefit). Finally, warming would also cause the extinction of many species.
Solutions & Solutions
With this problem in mind, countries have come together and presented proposals to gradually reduce the emission of greenhouse gases. It is possible, for example, to reduce the consumption of fossil fuels if there is more efficient equipment, which burns less fuel. Another way out is to invest in the use of alternative energy sources, which do not emit carbon dioxide.
In these discussions, the poor countries recall that the rich, more industrialized, are in general the main responsible for global warming, since they consume, proportionally, more fuel and energy.
For example, with 5% of the world population, the United States is responsible for about 25% of the emission of gases that increase the greenhouse effect worldwide. That is why developed countries must control more the emission of these gases and the waste of energy.
The United States argues that these measures cannot be adopted quickly, as they can cause unemployment (the economy would be slowed), and insist that poor countries must protect their forests, avoiding fires and promoting reforestation.