Evolution of energy

In this graphic we can see the evolution of final energy in the world. We can observe that according to the minister of science and technology we use a lot of petrol. After, we can see that the second product that we use is electricy, gas, carbon, hot and renovable energy.
I think that the colours play an important role in this graphic because they help at the viewer to understand what are the principal energies consums comparing three different years: 1971, 1997 and 2020.
We can see that the energy increases a lot of tonelades in the recent years especially the petrol because this energy is very important in nowadays and we often use it for our cars, and all of transports in general. In a futurs, according to the stadistics the level of energy increase more. 
It's for this reason that in thegraphic we can see that in 2020 will be use a lot of energy tonelades. 
This tonelades have different problems for example, the pollution. In nowadays in our cities the pollution increases so much. This pollution affects at the vegetation, plants, animals but especially at people. I think that is important try to consume less because if we continue in this line, in 2020 the future of the cities and the world in general, will be in danger.