Trapped greenhouse gases increase the temperature of the atmosphere, oceans and land, and this creates a ripple effect that interrupts the rain cycle, causing more intense precipitation. Subsequently, due to the trapped greenhouse gases, the earth's temperature increases; making it much hotter than it should be. The increase in temperature in turn melts the polar ice caps causing a rise in sea levels; because of this, more land is lost by being swallowed up by the Earth's increasing mass of water. The natural ecosystem is therefore negatively affected by extreme weather conditions and rising sea levels. For example, animals living in the tropics can see their habitats destroyed by violent typhoons, while animals such as polar bears lose their habitats when the polar ice caps melt. According to the US Environmental Protection Agency (EPA), “average global temperatures have risen more than 1.4°F over the past century.” (Climate Change Facts, EPA). Of the 100% of the energy the earth receives from the sun, only 30% is absorbed by the earth, while the remaining 70% flows back. The earth therefore emits absorbed energy because it is significantly hotter than the sun; however, greenhouse gases prevent this from happening, causing the earth to warm. In addition to natural sources of greenhouse gases such as volcanoes, human activities such as deforestation have a favorable effect on greenhouse gases. This is evidence that the earth's temperature has increased due to trapped solar radiation entering the atmosphere but failing to leave it. The latest global environmental problem is overpopulation; this happens when a specific population exceeds the optimal capacity of its ecological niche. As previously mentioned, humans are at… middle of paper… at the beginning of 1999 they were at 6 billion and are expected to be at 9.2 billion by 2050 and increasing further as the years go by. This is a significant problem because if people do not use contraception or do not implement adequate family planning, natural resources will be depleted. The UN has stated that if fertility is not maintained at 1995-2000 levels, the world will suffer from overpopulation and the number will reach 244 billion by 2150 and 134 trillion by 2300. Furthermore, the increase in human population Pollution has increased in many third world countries. For example, the overpopulation rate in Africa is very high and with this many unfortunately live and are tormented by diseases. For example, because family planning is not practiced and there is inaccessibility to medicines, diseases such as malaria and HIV are widely spread across the continent.