The concentration of CO2 has brought a considerable decrease of public health due to the increase of lung diseases and respiratory system diseases  also the increase and spread of infectious diseases. This CO2 problem  causes the greenhouse effec, that has as a consequence the climate change produced by the The average  temperature of the Earth's surface has increased throughout the twentieth century by 0.6 ° C. In the XXI century it is expected that the global temperature will increase between 1 and 5 ° C. The climate change has brought the increase frequency and intensity of extreme meteorological events.

 

In the city the biodiversity is decreasing for the displacement of species to cooler altitudes or latitudes, looking for climates to which they are accustomed. Those species that are unable to adapt  will become extinct.