As of today, the world’s population is approximately 7.2 billion people. According to the United Nations, by 2100, the world’s population will reach to 11 billion people. There are several reasons for the fast growing population. It’s well known that the growing population is compounding the problem of and adding to global warming. The more people, the more fossil fuels are used to meet the needs of the demands for more energy to sustain life. Thus the growing demand for fossil fuels means burning more oil, gas and coal which sends more carbon dioxide into the atmosphere which builds up greenhouse gases.
With global birth rates’ remaining higher than the replacement fertility rate; fertility is declining in almost all countries. At the global level, the crude birth rate, the number of live births in a given time period and population, fell from 37 births per thousand in 1950–1955 to 20 per thousand in 2005–2010. Furthermore, epidemiological advances have dramatically increased the average life expectancy over the past five decades; from 47 years in 1950-1955 to 65- 68 for men and 70 years for women in 2005-2010.
Migration is another aspect of the demographic transition period. It based on the connection between birth & death rates and industrial development. The migration process occurs over four-stages, from a rural to rural migration to rural-urban migration, and lastly to international migration. According to the UN, the following may have a direct impact on the environment:
- “rural-rural migration produces direct household impacts on natural resources, often through agricultural expansion;
- rural-urban migration and associated livelihood changes are often accompanied by changing patterns of energy use and increased meat and dairy consumption, which can intensify land pressures in productive rural areas; and
- International migration, with remittances sent home, can have a direct impact through land-use investments or an indirect impact through increased meat, dairy and material consumption”.
In 1950, less than 30% of the world population lived in urban areas. In 2010 the population increased to 50%. Also, in 2010, there were 20 cities with a population of 10 million people predominantly in Asia and Latin America. In 2013, the city of Karachi had over 23 Million inhabitants. It is expected to grow to over 26 Million by 2025. Lahore, another city in Pakistan, had over 12 million inhabitants in 2013.Recently, urban growth rates are high in both Asia and Africa, and Middle-sized cities have the highest rates. However, urban settlements use only 0.5% of the world’s land surface area, and over 37% of the surface is for agricultural production.
The rise in human population and the increasing economic activities are the reasons for the environmental problems that pertain to the water, the air, the soil, the animals, and the plants.According to the Center for Biological Diversity, the “…unsustainable human population growth can overwhelm efforts to reduce their carbon footprint through less consumption and better technology…leading us to conclude that we not only need smaller footprints, but fewer feet.”