A resource that was being created slowly during millions of years, theoretically by organic material. Today it's the main resource for energy and the cause of the great development in comparison with other epochs. With a resource of this kind, the civilization easily found and incredible method to achieve a revolution in construction or transportation and then, of course, in almost any industry.
It's liquid nature permits storage during indefinite periods and besides, hydrocarbons have a high energy density and that's the bar today, considerably raised to compete with.
Nevertheless, the main issue with this energy resource appears with the atmospheric contamination and the absorption of carbon dioxide in water bodies like seas or oceans. It heavily affects cities and their population; even living in places where the combustion cannot charge the air until extreme proportions, the pollution finally affects everybody for other mechanisms.
The climate has to many factors for being analyzed in words, although for sure the emission rate is a modifying factor that has been proved as a system that increases temperature leading to abrupt changes and with them more chances to instability. The complexities of the emissions that billions breathe right now include not only carbon dioxide but multiple other chemicals coming from motor oil and petroleum refinement, or other possible byproducts in the emission chain. When the combustion is not correctly done, and the catalyst doesn't exist or works at a lower percentage of success, partially burnt hydrocarbons are released into the public air. Some of the aforementioned elements would be seen more dangerous than tobacco considering different circumstances.
Carbon monoxide is another usual emission, a lethal gas that every year causes fatalities in dependance of the concentration. As it happens, the quality of the air diminishes as the hydrocarbon reality uses the atmosphere as a dump by high numbers thus the problem gets bigger with each new emitter. A problem that affects health in many ways.
Is it necessary? We think it is only a matter of time to prove that no because right now there are solutions.