Current Population of Humans On Earth: Over 7 billion and counting
Overpopulation is seen around the world. Where there is livable land, there are bound to be people living there. Too many people can lead to too many problems. According to the Science article, "Human carrying capacity",
"Over the last 2000 years, the annual rate of increase of global population grew about 50-fold from an average of 0.04% per year between A.D. 1 and 1650 to its all-time peak of 2.1% per year around 1965 to 1970 (3). The growth rate has since declined haltingly to about 1.6% per year (4) (Fig. 1). Human influence on the planet has increased faster than the human population. For example, while the human population more than quadrupled from 1860 to 1991, human use of inanimate energy increased. The author is in the Laboratory of Populations, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. from 109 (1 billion) megawatt hours/year (MW'hours/year) to 93 billion MW' hours/year (Fig. 2)" (Cohen, 1995).
In other words, by having a large population, more people will use more resources which can have negative consequences on Earth as well as its organisms that live there too which includes human beings.
Consider for example, China. According to the United Nations Department of Economic and Social Affairs Population Division's article, "World's Population 2012,” the expected population in China for the year 2013 is about 1,385,567,000 people making it the most populous country in the world (World's Population, 2012). When there are more people, there is more demand for supplies. According to The Economist's article, "The New Colonialists," China "...accounts for about a fifth of the world's population, yet it gobbles up more than half of the world's pork, half of its cement, a third of its steel and over a quarter of its aluminum. It is spending 35 times as much on imports of soya beans and crude oil as it did in 1999, and 23 times as much importing copper—indeed, China has swallowed over four-fifths of the increase in the world's copper supply since 2000" (“The New Colonialists,” 2008). This means that a single country in the world is using more resources than other developed or developing countries on Earth that can benefit their lives. If China had less people like other countries-Seychelles, Seychelles, etc.- they would not need as much materials to sustain their large population.
Moreover, consider the nation of India. According to the United Nations Department of Economic and Social Affairs Population Division's article, "World's Population 2012," the expected population in India for the year 2013 is about 1,252,140,000 people making it the second populous country on Earth (World's Population, 2012). According to the World Population Awareness, "...after gaining independence and being in charge of its own destiny, half of its people live on less than $1 a day...53% of children under five are malnourished; 71% have no access to sanitation; 37% have no access to safe water; and there are around 100 million child laborers. 20% of the world's maternal deaths and 25% of its child deaths occur in India. Delhi, Mumbai and Chennai are three of the world's ten most polluted cities" (World Overpopulation Awareness, 2014). According to water.org, "India’s huge and growing population is putting a severe strain on all of the country’s natural resources. Most water sources are contaminated by sewage and agricultural runoff...the World Bank estimates that 21% of communicable diseases in India are related to unsafe water. In India, diarrhea alone causes more than 1,600 deaths daily" (Water.org, 2014). A lot of people in India do not have access to clean water and many of them are dying every day from disease, undernourishment, and more due to having a large population that India itself cannot maintain properly. For example, "in the city of Bombay, more than half of the 15 million people sleep on sidewalks or live in mud-and-tin huts. For many of its poor people, every child is a potential wage earner: a servant in a house, an understudy in a motor garage, someone to do odd jobs" (World Overpopulation Awareness, 2014)
Next, compare so called “third world countries,” like Timor-Leste, Malawi, Somalia (Countries of the Third World, 2014). Although this may sound vague, third world countries are contributing more to overpopulation than developed countries like India and China. For example, according to the United Nations Department of Economic and Social Affairs Population Division's article, "World's Population 2012," it is estimated that in 2013, more developed countries only accounted for 1,252,805,000 people while less developed countries accounted for 5,909,315,000 people (World's Population, 2012).
"The 49 least developed countries (LDCs) as a whole still have the fastest growing population in the world, at 2.3 per cent per year. Although this rate of increase is expected to slow significantly over the next decades, the population of the LDCs is projected to double by mid-century, from 898 million in 2013 to 1.8 billion in 2050, further increasing to 2.9 billion in 2100. Growth in the rest of the developing world is also projected to be robust, though less rapid, with its population rising from 5.0 billion in 2013 to 6.4 billion 2050 and then to 6.6 billion in 2100 according to the medium variant" (United Nations, Department of Economic and Social Affairs, Population Division, 2013).
Even though less developed countries will contribute to most of the population growth, it doesn't mean that they should be the only ones that should decrease their overall population. In order to experience success in lowering the population, every country, every state, every person has to contribute to the effort in order to have a sustainable Earth.