How long will it take humans to stop using these fossil fuels and only use hydroelectricity, making it available to everyone? Several years or even decades, and the pollution will gradually decrease instead of stopping overnight. Moreover, do the large countries, the populous and others have the capacities to make these changes quickly while also decontaminating. How many decades can the atmosphere still absorb pollution before a permanent climate instability is caused by human pollution? The main source of filtration for this pollution is land vegetation, vegetation, trees, and with the increase in the world population we will need more places to accommodate them as well as for agriculture. Therefore more people, less vegetation, more pollution. We can see the adverse effects of these concentrations of pollutants in cities in the form of smog. One day the pollution from Asian countries will reach us and we will not be able to do anything because we cannot put the barrier into the air! The planet continues to be poisoned a bit more every day with this growing population.