The term globalization is commonly used now, and it doesn’t only bring benefits to the world but also many problems. The purpose of this paper is to define and discuss the cause and effect of four global issues: overpopulation, water scarcity, global warming, and marine pollutions. The increasing number of population will cause serious problems in the future and I really want to know why was the population unstoppably rising and how humans will do to prevent overpopulation. So overpopulation is an issue that I want to know and find some solutions about. Global warming is affecting everything on the earth now; species living in the Arctic are dying, including one of my favorite animals, polar bears. So I want to learn about global warming and find ways to save polar bears. There are many people suffering by water scarcity; they can’t drink or use clean water, and some of them died because of thirst. I want to help them to have the same lives as we do, so I chose to research on water scarcity. Last but not the least, the leakage of oil in the ocean is happening more frequently, this has affected the lives of marine animals a lot. It will cause bigger problem if we can’t solve it, so I would like to find some solutions about it.
Overpopulation is a condition where an organism's numbers exceed the current carrying capacity of its habitat.(Kulkarni 2012)The term often refers to the relationship between the human population and the Earth, or smaller areas such as countries.
One thousand years ago, there are only 60 million people in the whole world; but since 1960, the rate of population increased incredibly every year. (Oak 2012) The increase of birth rate, life spans of humans, and the decrease of death rate are all main causes of overpopulation. On the one hand, the progress on medical domains and the improvement of technology can make people’s lives better and promote human cultures; on the other hand, because of these technologies, people can live longer now and be cured from diseases; this incredibly increases human longevity. That means there are more people born and less people die than before; so the control or the balance of population will finally cause the overpopulation.
The effect of overpopulation is mostly incarnated in three aspects: economy, politics, and environment. When the number of population in a country is increasing, more food must be supplied, and this will increase the national budget for the country; when the country can’t afford it, they borrow money from other countries and owe national debts. Secondly, more people will cause will cause more conflicts, so overpopulation will cause more wars. Nevertheless, every human lives on the earth takes spaces and breath, so there will be no enough space and oxygen for humans when population exceed its capacity.
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C, with about two-thirds of the increase occurring since 1980. (National Geographic 2013)
I believe that there are both natural and man-made causes of global warming. Natural causes are causes created by nature. One natural cause is a release of methane gas from arctic tundra and wetlands. Methane is a greenhouse gas that traps heat in the earth's atmosphere and rises the temperature of our planet. Another natural cause is that the earth goes through a cycle of climate change lasts about 40,000 years, and now the earth is this kind of cycle. (National Geographic 2013)Furthermore, burning fossil fuels and overpopulation are actually the major causes of global warming. Carbon dioxide is released by factories and countless cars; when there are more people on the earth, the more carbon dioxide will be produced and speed up the...