It may seem hard to believe that people can actually change the Earth’s climate. But scientists think that the things people do that send greenhouse gases into the air are making our planet warmer. Once, all climate changes occurred naturally. However, during the Industrial Revolution, we began altering our climate and environment through agricultural and industrial practices. The Industrial Revolution was a time when people began using machines to make life easier. It started more than 200 years ago and changed the way humans live. Before the Industrial Revolution, human activity released very few gases into the atmosphere, but now through population growth, fossil fuel burning, and deforestation, we are affecting the mixture of gases in the atmosphere.
Since the Industrial Revolution, the need for energy to run machines has steadily increased. Some energy, like the energy you need to do your homework, comes from the food you eat. But other energy, like the energy that makes cars run and much of the energy used to light and heat our homes, comes from fuels like coal and oil – fossil fuels. Burning these fuels releases greenhouse gases.

Have you ever seen a greenhouse? Most greenhouses look like a small glass house. Greenhouses are used to grow plants, especially in the winter. Greenhouses work by trapping heat from the sun. The glass panels of the greenhouse let in light but keep heat from escaping. This causes the greenhouse to heat up, much like the inside of a car parked in sunlight, and keeps the plants warm enough to live in the winter.The Earth’s atmosphere is all around us. It is the air that we breathe. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up.

The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.

Between 1950 and 1998, the world's population grew from 2.5 billion to 5.9 billion human beings. United Nations demographers project world population will gain between 2 and 4 billion more people by 2040 (United Nations 1998). Just as past population increases have influenced greenhouse gas emissions and the composition of the earth's atmosphere in the late 20th century, future demographic trends will affect the earth's climate for centuries to come.Global efforts to reduce fossil fuel use, increase energy efficiency, slow deforestation, and move to carbon-free energy sources are key components of decreasing greenhouse gas emissions. Such efforts, the objective of current negotiations on climate change, are much more likely to have enduring success if world population grows more slowly and eventually stabilizes.The disparities in resource consumption and greenhouse gas emissions between regions, nations, and individuals complicate international efforts to address climate change, since responsibility for the problem varies so broadly. These disparities also cloud the role of population growth in changing climate, since the greatest per capita contributions to climate change are made by populations, such as those of the United States and Europe, that are growing relatively slowly or have stabilized.

According to the International Programs Center, U.S. Census Bureau, the total population of the World, projected to 09/20/07 at 00:05 GMT (EST+5) is
6,619,373,505

Monthly World population figures:

The Planned Birth policy is the birth control policy of the government of the People's Republic of China (PRC). It is known in Western society as the One-child Policy due to the required payment of a "social compensation fee" for couples having more than one child in an urban area. China's generally perceived pandemic overpopulation problem, with the associated social and environmental problems, forced the government to take strong unique measures in population planning policy. The policy is controversial both within and outside China due to allegations of extreme methods such as forced abortions and other human rights abuses by the local authorities. Punishmnets may included amputation of genitals and forced sterilization.

India
"The Indian Government was one of the first to formulate a National Family Planning Programme in 1951, which was later expanded to encompass maternal and child health, family welfare and nutrition. The government is committed to promoting the small family and to support population programs.
However, during more than three decades of population programs 'watch', I have found that there is a huge gap between 'planning' and its actual 'execution' and many of our statistics are screwed up. As a result, population 'explosion' continues unabated... According to the United Nations Population Information Network (POPIN), the annual growth rate of India is still 2.14% and the Total Fertility Rate (TFR) (sum of age specific fertility rates in a specific year) is 3.5. The women aged 15-49 using modern contraception methods were only 36%. On May 11 this year, we announced amidst much publicity glare the birth of the one billionth child, Aastha. Since then quite a few more million babies have been added to our population.
Our population now is second only to China. . . The comparison with China is misleading since China has about 20% of the world population and 7% of land area. In contrast, India has about 16% of the world population but has only about 2.4% of the total land area.

NEW UN REPORT CITES DEVASTATING EFFECTS OF HIV/AIDS

The HIV/AIDS epidemic will have devastating consequences in the decades to come for virtually every sector of society ranging from households and farms, to growth of whole economies, according to a new report, The Impact of AIDS, issued today by the Department of Economic and Social Affairs’ Population Division.

Without an effective vaccine or cure, or much more effective programmes to prevent the epidemic’s spread, HIV/AIDS will cause as many as 100 million excess deaths in sub-Saharan Africa by the year 2025. The pandemic is also projected to kill 31 million additional people in India and 18 million in China by then.

HIV/AIDS has emerged as the single most significant population concern among countries of the world, the report says. In most developing countries, especially sub-Saharan Africa, the epidemic is undermining the possibility of achieving the Millennium Development Goals adopted by the United Nations General Assembly in 2000.

Key Report Findings

-- HIV/AIDS has a devastating demographic impact. It has already killed over 20 million people. Between 1980, when the epidemic started emerging, and 2025, HIV/AIDS will cause about 100 million excess deaths, out of 500 million total deaths in sub-Saharan Africa. In India, AIDS is expected to claim 31 million lives over the same period, and 18 million in China.

-- The burdens of HIV/AIDS on families and households are staggering. During the long period of illness, the loss of income and the cost of caring for family members may impoverish the household. Adult deaths, especially of parents, often cause the break-up of households, with children being sent to live with relatives or even becoming homeless.

-- HIV/AIDS seriously threatens the education of children. In households affected by HIV/AIDS, children are often taken out of school to help at home with caregiving or to earn an income. In addition, teachers are also dying of AIDS, eroding the quality of education.

-- HIV/AIDS threatens the viability of health-care systems. Treating AIDS and related opportunistic infections is placing heavy burdens on the health systems of developing countries.

-- The loss of farm workers to HIV/AIDS undermines food security. The 10 most severely affected African countries will lose between 10 and 26 per cent of their agricultural labour force by 2020.

-- HIV/AIDS affects business enterprises as well. Ill workers are less productive, as are those workers who must care for ill family members. The costs of replacing experienced workers and paying health and death benefits is becoming a serious financial drain on businesses.

-- HIV/AIDS weakens the economy and has begun to stall economic development. Where HIV prevalence is high, experienced workers are lost, and funds for investment may be diverted to pay for health care and support of afflicted families. Lower investment in human capital -- the health and education of the next generation —- will undermine prospects for development for many years to come.

Immediate and concerted actions to prevent new infections, and treatment and care for people living with HIV/AIDS have become an imperative, the study suggests. “The course of the HIV/AIDS epidemic is by no means pre-determined”, concludes the report. “The eventual course of the disease depends on how individuals, communities, nations and the world respond to the HIV/AIDS threat today and tomorrow.”

According to United Nations projections (medium variant), the world's population will increase by 72 percent between 1995 and 2050। It is hoped that by that time food deficits will be reduced, per caput food consumption in countries suffering from shortages will increase and the diets of populations will be diversified in order to eliminate specific deficiencies. All these changes will weigh heavily on food production systems, natural resources and the environment.
The main question is whether the required improvements in food production and available natural resources will be enough to cope with this population growth in a sustainable manner until 2050, when the world’s population is projected to stabilize. The distribution of natural resources needed for agricultural production does not correspond to the geographical distribution of population, and migration does not necessarily compensate for this difference in distribution, which can cause additional difficulty. This issue is relevant at the local, national, regional and international levels.