An endangered species is a plant or an animal that faces a high risk of disappearing forever. Sometimes this happens because they have lost their natural habitat, at other times humans are the cause for such species becoming extinct.
Weather is the state of the atmosphere in a certain place at a certain time. Climate refers to the weather conditions of a region over a longer period of time.
Air pollution, as we know it today, started with the Industrial Revolution in Europe in the 19th century. In the last few decades, it has become the major problem for our environment.