How and where can the next generation live and survive?The consequences of over population cause many effects on the environment, which might cause extinction of many species and the most important is human species. In 1996, the World Conservation Union (IUCN), completed the first-ever extensive survey of the status of animal life on Earth. The 600 plus participating scientists concluded that of the species surveyed, 34 percent of fish, 25 percent of mammals and amphibians, 20 percent of reptiles, and 11 percent of birds are threatened with extinction. Another 5 to 14 percent of species in these groups are “nearing threatened status. ” “The leading cause of vertebrate declines is human destruction of old growth forests, wetlands, chaparral, and other rich habitats,” Worldwatch reports. “Worldwide, over two-thirds of the earth’s habitable land surface has been significantly disturbed by human activities.
Nearly half of the world’s 233 primate species are threatened, largely because of their dependence on large expanses of tropical forest, a habitat under siege around the globe. In hotspots of forest loss, such as Madagascar, the Atlantic rainforest of eastern Brazil, and Southeast Asia, roughly 70 percent of primate species face extinction. ” from Losing Strands in the Web of Life: Vertebrate Declines and the Conservation of Biological Diversity by John Tuxhill, Worldwatch Institute. And one day on the earth there will be no animals, no trees and the ocean is fulfilled with waste and dust. People cause all of those things by the over of population by the over use of resources instead of adding more value to them, make them become richer, and people or the next generation can use them in 100 years. The over population makes it harder to control or to organise all sorts of things.
According to a study of 50 countries by Paul Harrison (“The Third Revolution,” Taurus, 1992) those areas with the greatest population density retain the least wildlife habitat. For example, countries with population densities under 294 people per square kilometer (such as the US) retained an average of 59 percent of wildlife habitat. Nations with densities under 379 per square kilometer retained 45 percent on average, while nations with densities of up to 454 per square kilometer retained only one third of their original habitat. In the most crowded countries – averaging from 1190 to 1888 people per square kilometer – barely 15 percent of original habitat remained. In the future there will be more and more people in a small place and the original habitat will endanger.
Moreover, human activities negatively affect the Earths atmosphere through releases of pollution that causes smog, acid rain, and depletion of the ozone layer. This is directly related to human numbers and lifestyles, because it is largely a result of emissions from automobiles and industrial plants. World vehicle production is now approaching 40 million units annually, and the total world fleet is half a billion vehicles. As more people operate more automobiles and demand more energy produced by burning oil, coal and natural gas, emissions and therefore air pollution will increase further. Increasing levels of carbon emissions are also linked to what may be the most serious long-term threat to humanity – global warming and climate change.
Because of the pollution, it affects peoples health such as the blood of children in the urban area has lead content levels much higher than childrens in rural area. And people who live in urban area have higher chance of having high blood pressure or higher death rate causing by cancer or other diseases than people in rural area have.What have people done .