Man Made

  What Is Air Pollution? Air pollution  refers to the release of pollutants into the air—pollutants which are detrimental to human health and the planet as a whole. According to the World Health Organization (WHO), each year air pollution is responsible for nearly seven million deaths around the globe. Nine out of ten human beings currently breathe air that exceeds the WHO’s guideline limits for pollutants, with those living in low- and middle-income countries suffering the most. In the United States, the  Clean Air Act , established in 1970, authorizes the U.S. Environmental Protection Agency (EPA) to safeguard public health by regulating the emissions of these harmful air pollutants. What Causes Air Pollution? “Most air pollution comes from energy use and production,” says  John Walke , director of the Clean Air Project, part of the  Climate and Clean Energy program  at NRDC. “Burning fossil fuels releases gases and chemicals into the air.” And in an espe...

Seal   commonly known as seals,are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago. 👌