Human Population Size And Climate Change Environmental Sciences Essay

Over the years, human society has changed the local ecological system and caused the change of regional climate. Today, mankind has begun to affect the entire planet’s climate. The world’s population in the next 12 to 13 years will increase more than 1 billion. It is predicted that by 2020, the population will increase to 76 billion from the current 6.5 billion, in 2030 to 8.2 billion, in 2050 to staggering 9.0 billion. There is a huge gap between population growth and food supply growth. When the population growth exceeds the capacity of the food supply, famine is inevitable. The more people mean needing more air, water, and more housing, education and employment opportunities. To meet these, people will ignore the prevention and treatment of the serious consequences of climate change. But climate change has caused global warming and rising sea levels, which could lead to the destruction of the Earth’s civilization without any measures. Humanity in the process of production and consumption make destruction, pollution and impact on the environment, but changed environment also affects the survival of mankind. The relationship between population and the environment has been objective relationship since the origins of mankind. The population development is a special kind of social process, which is mainly determined by economic and social conditions. During a social process, population and environment have the opposite and unity relation of interrelatedness, interaction, and mutual restraint. This essay will first discuss the development of population size and the problem. Following this, it will describe the impact of population on the climate. Finally it will describe impact of climate on the population.

Development of population size and the problem

Overall, the world’s population growth is relatively fast. The second half of the 20th century, the world had an unprecedented rapid population growth. Not only the population growth rate reached a historic peak level and increment of the population exceeded the total accumulation population in more than 200 million years of human history. U.S. Census Bureau data showed that the world’s population in 1930 reached 20 billion, in 1974 to 40 million, in 1987 to 50 million, in 1999 to reach 6.0 billion. The population growth rate has been accelerating in the 20th century. The world’s population had doubled in 1850-1950 years, while in 1950-1990 a short period of four decades had doubled. At present, in the world about 365,000 people born every day, of which 57% born in Asia, 26% in Africa, 9% in Latin America, 5% in Europe, but was born in North America and only 3%. In addition, less than 1% of the population is born in Oceania and the oceanic islands. After subtracting the number of deaths, the global average daily increase is nearly 21 million people. The Earth increases by nearly 80 million people each year, almost equivalent to a large population country. India is one of the world’s youngest population countries, more than half of the national smaller than 25 years of age, 1/3 of the population smaller than 15 years(Ehrlich, 1997).. “World Population Prospects” published by United Nations predicts that by 2050, India’s population will increase to 1.593 billion

In this century many scientific observations indicate that concentrations of greenhouse gases in atmospheric are increasing. Prior to 1750, atmospheric carbon dioxide levels remained at 280ppm. After the industrial revolution, as human activities, especially the growing consumption of fossil fuels (coal, oil, etc.), massive destruction of forest vegetation and the growing man-made emissions of carbon dioxide and other greenhouse gases, atmospheric carbon dioxide level gradually increases, per year increasing 1.8ppm (about 0.4%), and it has risen to nearly 360ppm so far. In the past century, global average surface temperature has risen by 0.3 ℃ to 0.6 ℃, the global sea level rise of 10-25 cm (EPA, 2006). Recent years, countries around the world have emerged the hottest weather over centuries, and the frequent occurrence of El Niño phenomenon, which have caused tremendous economic losses. With the reduction in per capita grain area, more and more countries bear the risk of loss of food self-sufficiency. The extension of water scarcity is perhaps the most undervalued resource problems in the contemporary world. However, in any areas where the population is still growing, per capita fresh water supply is decreasing.

Impact of population on the climate

In the human production and life, over-grazing, deforestation makes the soil erosion, land degradation; super-exploitation of resources has led to depletion of a lot of natural resources; a variety of waste emissions cause serious environmental pollution and damage, which cause a series of global environmental issues. Population size, distribution, migration have also a huge impact on regional ecological environment. At present, the environmental changes caused by the rapid population growth and rapid development of urbanization have begun to affect the global biogeochemical cycles and long-term climate change, and become an important “eco-driving force” for large-scale changes in the environment and population.

1). According to UN information, per capita cultivated land was 0.31 hectares in 1975, and in 2000 it drop to 0.1 hectares due to population growth. In the condition of huge population and the relative decrease in the arable land, raising yield per unit area is a positive way to increase the grain. It relies mainly on chemical fertilizers and pesticides to reach the aim. However, large-scale use of fertilizers and pesticides has brought serious environmental problems such as soil compaction, poor physical and chemical properties, organic matter reduction and the fertility decline. 2). Forest is an important factor to maintain the quality of the environment for human survival. However, population growth is bound to destroy forest for cultivated land, or to build a house. As a result, an increasing number of forest resources are destroyed. Forest area on the planet had reached 76 million hectares, in 1962 reducing to 55 million hectares, in 1975 reducing to 26 million hectares. According to the calculation of American scholar, with the population growth, depletion of forests will be extended to the year 2020. Then forest area will stabilize at 1.8 billion hectares, of which about 1.45 billion hectares are in developed countries, only 370 million hectares in developing countries. Because the forests are heavily exploited, topsoil on the earth being that are washed away are 24 billion tons every year, loss of several million tons of fertilizer, having a great bad impact on farmers and livestock production. 3). Rapid growth and high concentration of population have brought tremendous pressure on the environment. Environmental pollution is one of the most serious mankind facing problems, such as: air pollution, water pollution, traffic congestion, noise nuisance, accumulation of garbage and so on. Population growth will increase carbon dioxide, nitrogen oxides and sulfur oxides in the atmosphere due to respiration, combustion and industrial development, which may cause acid rain and photochemical smog events. More serious is to cause the earth’s average temperature increase to affect climate due to the greenhouse effect caused by the increase in carbon dioxide, resulting in serious damage to the planet’s ecosystems (Smith, 2008).

Impact of climate on the population

Population distribution, migration and the quantity and quality depend on certain region environmental conditions to a considerable extent. Therefore, the relationship between population and the environment have obvious regional characteristics because of the different regional conditions. Integrated resource supply capacity of environment plays an important role in population distribution and migration. Quantity and quality of the population are affected by natural and social environment, the dual constraints. Population is the unity of its quantity characteristics and quality characteristics. Population quantity and population characteristics and physical appearance are all severely constrained by the environment. The demographic impacts of climate change on population are mainly in the following aspects.

1) Population growth makes a pressure on water supply and demand pressure, even without considering the impact of climate change, by 2050 there will also be 5 billion people facing water shortage situation, more than half of the world’s population. Impact of climate change makes the water problem even worse. Rivers dried up and falling water table are regarded as evidence of shortage of water resources, such as the Nile, the Yellow River and the Colorado River, which almost have waterless flowing to sea. At present, the world water tables of major grain-producing areas are falling on every continent. The U.S. southern Great Plains, the North China Plain and in most parts of India, groundwater aquifers are becoming increasingly dried up. International Water Management Institute predicts that in 2050 year in some countries a total of about 1 billion people live will face absolute water scarcity situation. These countries will reduce agricultural water to meet the needs of residents and industrial water demand. China and India are considered the world’s two major agricultural irrigation countries, and will have a significant reduction in irrigation water supply (Leigh, 2007). 2) Extreme weather and sea level rise have the most serious effect on the coastal and low-elevation areas, and coastal areas accounting for 2% of the total land live on 10% of the population around the world. Take Bangladesh and China for example, in 1990 to-2000 years, population growth rate living in coastal areas is twice the national rate of population growth. In the negative effects of sea-level rise and extreme weather, number of living people is growing. Others such as landslides, flash floods and glacial lake overflow and other issues also have impact on the human. It is expected 40% of the world’s population will be affected by the Asian mountain glaciers and snow melting. 3) The agricultural productivity reduces. Tropical and subtropical agriculture are most affected, because the region’s crop is already under the extreme climate varieties. As the population growth, reduced crop output and increasingly higher food prices, to 2080, will cause 90000000-125000000 population in developing countries facing the problem of hunger. 4) The global climate change often leads to severe changes of regional climate and weather, which have wide-ranging implications on human health. Global climate warming causes more heat in summer and temperate in winter, which is accompanied by an increase in frequency and intensity of heat waves. Humidity increase aggravates the effect of extreme heat in summer on human health. In temperate regions, high temperature increases the number of deaths during the day to day. For example, the United States during the heat wave in Chicago in 1995, the death was over 500, of which the highest mortality is at older ages. The future, as increase in frequency and intensity of heat waves, deaths number and serious illnesses caused by extreme high temperature events will increase. Also, because of air pollution, during the heat wave in 1995, the United States, it was estimated that more than half the number of deaths was caused by increased air pollution (Jonathan A. Patz, 2005). Flood causes casualties and infectious diseases to increase (P. Martens, 1999). Drought affects food production, and exacerbates the existing situation of malnutrition, inducing famine to affect human health. During the drought and water shortages, the water only is used for cooking but not for health, so that it increases the risk of disease and epidemic disease outbreaks.

Conclusion

Sir Nicholas Stern in 2006, in “Stern Report” pointed out that climate change could trigger the worst ever and the most extensive market failure. He warned that the world must invest one per cent of gross domestic product to slow the effects of climate change, the cost of failure to do so is the economic downturn of up to 20 percent of being the world’s gross domestic product. Climate change is a serious challenge to the whole world, and has an extensive impact on human well-being and safety. According to IPCC estimation, by 2050, due to coastal flooding, shoreline erosion and agricultural pollution and other reasons, there will be 150 million refugees. Investment in family planning and reproductive health, girl education, women empowerment and economic opportunities and youth development can accelerate demographic transition in the least developed countries and developing countries, so that they can seize the demographic dividend, to achieve economic growth, while to enhance the ability to address climate change. In strategies of adaptation to climate change, demographic factors should not continue to be ignored. It is necessary to take effective measures to meet the world’s most vulnerable populations, including women’s needs. Universal population policy of voluntary contraception, comprehensive consideration of population dynamics and development of poverty reduction will ultimately achieve sustainable population development adapting to climate change.