global warming

GLOBAL WARMING by-Ayush Katiyar 13117015 (Q 1) Today in the present scenario Global Warming is the current issue. One of the biggest problems facing the world today is global warming. Global Warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. There are many threats regarding our mother planet earth due to global warming. Some of them include melting of glaciers, increase in the temperature of earth, ozone layer depletion etc. The cause of this is human beings and their cause our needs have increased to such an extent that to satisfy our needs we are destroying our planet.It is estimated that everyday each individual contributes about 400 gram of waste in the environment which is basically packaging and this requires energy basically heat which is obtained from coal,natural gas,oil etc. Because of combustion process huge amount of carbon monoxide and carbon dioxide is produced which heat the earth surface. By far, the most prevalent of the greenhouse gases is carbon dioxide, the molecule that is emitted naturally through the respiration of animals and humans. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Warming of the climate system is unequivocal, and scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation. Study indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F change) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F change) for their highest. The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations. Global Warming leads to an increase in the sea level which makes which threatens the life of the people living near the coasts it is estimated that if the polar ice melts completely which will actually do It will raise the sea level to about 30 meters. This could result in the flooding of low lying coastal areas and cities, such as Egypt, the Netherlands, and Bangladesh. Another problem is changes in weather patterns. Many areas of the world are experiencing increased hurricanes, floods, and other natural disasters. A final issue associated with this phenomenon is the negative effect on animals. Fish populations could be effected, while some insects which spread disease might become more common. These are the business hub of the world if they would submerge this would lead to inflammation in the country and throughout the world as our world is of globalization. Moreover there will be many diseases like cancers, tumors which will cause epidemic. Future climate change and associated impacts will vary from region to region around the globe. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well as a probable expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with the continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include a more frequent occurrence of extreme weather events including heat waves, droughts and heavy rainfall, ocean acidification and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation. There are several things we can do to deal with global warming. One answer is to stop making C02. We can do this by switching from oil, coal and gas to renewable energy. A second solution is to plant more trees. Trees absorb C02 and produce oxygen, which is not a greenhouse gas. A third idea is to use less energy and recycle more products. If we use less energy and are more environmentally friendly, the earth’s temperature may not rise too much. In conclusion, making small changes now in the way we live means avoiding huge changes in the future. Scientists, governments and individuals must work together to overcome this serious threat.

The vast bulk of carbon dioxide emissions, however, comes from the burning of fossil fuels such as oil, gasoline, and natural gas, resources that are consumed heavily in automobiles, industrial production, and the generation of energy that is used domestically. The demand for these fuels is so widespread that it would be virtually impossible to stop their production and use on a global level. It was thought that, instead, a drastic reduction in their use might help decrease the amount of emissions into the atmosphere. However, the prospect of curtailing economic development locally in order to reduce greenhouse gases worldwide came at a time when many developing nations were firmly committed to making great economic strides and it proved to be a bitter political pill that few nations were prepared to swallow.
Although no single event could be blamed for the observed warming trend, scientists have suggested that the total effect of human activity on Earth since the Industrial Revolution contributed to the problem. Fossil fuel emissions were only one aspect of the scenario. Along with industrialization, human population growth resulted in increased demand for goods, services, and shelter. For example, high market demand for meat products results in increased livestock ranching, which contributes to increased greenhouse gases in two ways: not only do increased numbers of livestock mean increased emissions of methane gas, but they require increased grazing land at the expense of wooded habitat. Trees take up more carbon dioxide during photosynthesis than does grass; therefore, the clearing of land results in fewer trees that can use up the excess carbon dioxide in the air. Destruction of natural areas for urbanization also constitutes a two-pronged attack: trees and plants are cleared in favor of areas that can shelter enormous concentrations of humans who consume energy in tremendous amounts. Increased human population results also in higher demand for goods that are produced in factories that burn fossil fuels.
In some parts of the world, widespread deforestation worsened the problem of greenhouse gases. In Brazil, farmers were routinely encouraged by the government to burn their land in exchange for loans. In 1997, a record-breaking drought led to a dramatic increase in the need for loans, which resulted in a higher than usual incidence of these fires. The fires released greenhouse gases directly into the atmosphere and created smoke levels that threatened the environment and the surrounding human population; 30 percent of nearby residents sought treatment for respiratory problems.
Although no one disputed that greenhouse gases were emitted during the burning, there was disagreement about exactly how much was released. The Brazilian government contended that the country contributed less than 2 percent of the world's greenhouse gases—1 percent from the burning of fossil fuels, and 1 percent or less as a result of the intentional land burning. Some scientists believed the emissions were considerably higher, perhaps as great as 6 percent from the land burning alone. According to an international scientific panel, their best estimate regarding global warming was that a doubling of carbon dioxide in the 21st century would yield an increase in the Earth's temperature of approximately 3.5 degrees Fahrenheit by the year 2100. The increased temperature would drastically affect world climate and precipitation patterns. More frequent droughts and floods would accompany an intensified cycling of water between the oceans and the atmosphere. These droughts and floods would seriously affect agriculture, especially in Africa and other tropical areas. Sea levels would rise by almost 2 feet (0.6 meter), covering low-lying coastal areas. Increased nighttime temperatures would result not only in milder winter evenings but also in more disastrous heat waves. Increased air temperatures, along with increased humidity, would also result in an expanded range for disease-carrying insects, such as mosquitoes.
Some studies posited that it would be possible to limit the global temperature increase to a mere 1.5 to 2 degrees Fahrenheit by the year 2100. This could be achieved, however, only by keeping the carbon dioxide levels in the atmosphere at 450 parts per million. This level—nearly twice the level of carbon dioxide during preindustrial times—might be impossible to achieve and maintain, but some policy makers focused on it as the next plateau to reach. Most scientists, however, felt that stabilizing carbon dioxide levels at 550 parts per million might be a more realistic goal. The level of atmospheric carbon dioxide in 1997 was 360 parts per million.
Green house gases- A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere thatabsorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in theEarth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, andozone. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects. Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would average about 33 °C (59 °F) colder than the present average of 14 °C (57 °F). Atmospheric concentrations of greenhouse gases are determined by the balance between sources and sinks (the removal of the gas from the atmosphere by conversion to a different chemical compound). The proportion of an emission remaining in the atmosphere after a specified time is the "Airborne fraction" . More precisely, the annual AF is the ratio of the atmospheric increase in a given year to that year’s total emissions.
Water vapours accounts for the largest percentage of the greenhouse effect, between 36% and 66% for clear sky conditions and between 66% and 85% when including clouds.Water vapor concentrations fluctuate regionally, but human activity does not significantly affect water vapor concentrations except at local scales, such as near irrigated fields. The atmospheric concentration of vapor is highly variable and depends largely on temperature, from less than 0.01% in extremely cold regions up to 3% by mass at in saturated air at about 32 °C.
The average residence time of a water molecule in the atmosphere is only about nine days, compared to years or centuries for other greenhouse gases such as CH
4 and CO2. Thus, water vapor responds to and amplifies effects of the other greenhouse gases. The Clausius-Clapeyron relation establishes that more water vapor will be present per unit volume at elevated temperatures. This and other basic principles indicate that warming associated with increased concentrations of the other greenhouse gases also will increase the concentration of water vapor (assuming that the relative humidity remains approximately constant; modeling and observational studies find that this is indeed so). Because water vapor is a greenhouse gas, this results in further warming and so is a "positive feedback" that amplifies the original warming. Eventually other earth processes offset these positive feedbacks, stabilizing the global temperature at a new equilibrium and preventing the loss of Earth's water through a Venus-like runaway greenhouse effect.

Green house effect-
The glass windows of a greenhouse let in sunlight. The sunlight warms up objects inside the greenhouse. These objects then give off heat. The glass of the greenhouse, however, does not let out the heat. If the greenhouse lacks ventilation, all the heat stays locked inside and the temperature rises. This greenhouse effect also causes the inside of an automobile to become hot if its windows remain closed on a sunny day.
The Earth and its atmosphere are like a giant greenhouse. Like the glass windows of a greenhouse, the atmosphere is nearly transparent to shortwave and visible solar radiation. Part of the energy absorbed by the Earth is radiated to the atmosphere as long-wave infrared radiation. Because it contains carbon dioxide and water vapor, which absorb much of the long-wave radiation before partially reradiating it back to the surface, the atmosphere is not completely transparent to this long-wave radiation. This causes the Earth and its atmosphere to warm up.
Variations in the amounts of carbon dioxide and water vapor in the air can therefore have a significant effect on how much heat is retained by the atmosphere. The total amount of carbon dioxide present in the Earth's atmosphere remained nearly constant until the 20th century, when the burning of fossil fuels such as coal, fuel oil, gasoline, and natural gas began to release large quantities of carbon dioxide into the atmosphere.
The combustion of fossil fuels brought about an ever-increasing rise in the carbon-dioxide concentration in the atmosphere. Some scientists believe that, as the greenhouse effect is intensified, long-term climatic changes on the Earth will result. A number of scientists have predicted that human-related increases in atmospheric carbon dioxide and other greenhouse gases could lead to an increase in the global average temperature of 1.4 to 5.8 °C (2.5 to 10.4 °F) by the end of the 21st century. . Such a rise in global temperature, some scientists hypothesize, would produce new patterns and extremes of drought and rainfall, which would seriously disrupt food production. Temperature increases in the polar regions could be as much as three times greater than the global estimate, which would cause the polar ice caps to melt at a rapid rate and result in appreciably higher coastal waters.
Other factors may reduce the effect of an increase in carbon dioxide and thus prevent a rise in temperature. One of these factors is the rise in the amount of dust in the atmosphere, as the result of a volcanic eruption, for example. This could lead to greater reflection of the sun's light by the atmosphere, which would tend to lower the temperature on Earth. Another factor helping to minimize the effect of increased amounts of carbon dioxide is the greater absorption of the gas by the oceans. Some scientists believe that water vapor plays a much more significant role than does carbon dioxide in the Earth's greenhouse effect and that fluctuations in it are therefore much more important.
Effects-
The effects of global warming are the ecological and social changes caused by the rise in global temperatures. There is a scientific consensus that climate change is occurring, and that human activities are the primary driver. Evidence of climate change includes the instrumental temperature record, rising sea levels, and decreased snow cover in the Northern Hemisphere. According to the Intergovernmental Panel on Climate Change most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in human green house gas concentrations.
Projections of future climate change suggest further global warming, sea level rise, and an increase in the frequency and severity of some extreme weather events. Parties to the United Nations Framework Convention on Climate Change have agreed to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.
A broad range of evidence shows that the climate system has warmed. Human activities have contributed to a number of the observed changes in climate. This contribution has principally been through the burning of fossil fuels, which has led to an increase in the concentration of GHGs in the atmosphere. Another human influence on the climate are sulfur dioxide emissions, which are a precursor to the formation of sulfate aerosols in the atmosphere. Human-induced warming could lead to large-scale, irreversible, and/or abrupt changes in physical systems.
Climate change will impact agriculture and food production around the world due to: the effects of elevated CO2 in the atmosphere, higher temperatures, altered precipitation and transpiration regimes, increased frequency of extreme events, and modified weed, pest, and pathogen pressure. In general, low-latitude areas are at most risk of having decreased crop yields.
So far, the effects of regional climate change on agriculture have been relatively limited. Changes in crop phenology provide important evidence of the response to recent regional climate change.Phenology is the study of natural phenomena that recur periodically, and how these phenomena relate to climate and seasonal changes.A significant advance in phenology has been observed for agriculture and forestry in large parts of the Northern Hemisphere.
Droughts have been occurring more frequently because of global warming and they are expected to become more frequent and intense in Africa, southern Europe, the Middle East, most of the Americas, Australia, and Southeast Asia.Their impacts are aggravated because of increased water demand, population growth, urban expansion, and environmental protection efforts in many areas. Droughts result in crop failures and the loss of pasture grazing land for livestock.
Human beings are exposed to climate change through changing weather patterns (temperature, precipitation, sea-level rise and more frequent extreme events) and indirectly through changes in water, air and food quality and changes in ecosystems, agriculture, industry and settlements and the economy . Climate change was estimated to have been responsible for 3% of diarrhoea, 3% of malaria, and 3.8% of dengue fever deaths worldwide in 2004. Total attributable mortality was about 0.2% of deaths in 2004; of these, 85% were child deaths.
Global losses reveal rapidly rising costs due to extreme weather-related events since the 1970s. Socio-economic factors have contributed to the observed trend of global losses, e.g., population growth, increased wealth. Part of the growth is also related to regional climatic factors, e.g., changes in precipitation and flooding events. It is difficult to quantify the relative impact of socio-economic factors and climate change on the observed trend. The trend does, however, suggest increasing vulnerability of social systems to climate change.
Prevention
Prevention may also be achieved by increasing the capacity of carbon sinks, e.g., through reforestation. Examples of mitigation include switching to low-carbon energy sources, such as renewableand nuclear energy, and expanding forests and other "sinks" to remove greater amounts ofcarbon dioxide from the atmosphere. Energy efficiency can also play a major role, for example, through improving the insulation of buildings.
Transportation --- in particular, car travel --- is responsible for about 25 percent of energy use in the U.S., according to the EPA, and also puts chemicals and pollutants into the air. To reduce your emissions, change your driving habits. The easiest way to cut carbon emissions is to drive less: carpool to work, take public transportation, walk or ride a bike. Consider telecommuting to work; the EPA says that working at home even one day per week can significantly reduce your carbon footprint if you are a car commuter. Keep your car maintained so that it runs efficiently. Turn off your car instead of idling, and don't drive aggressively, as abrupt acceleration and driving at high speeds burns up fuel.
Conclusion
We must not waste energy and burn things as the release greenhouse gases in the atmosphere which cause global warming.And we must stop deforestation and start aforestation.If each person plants even one tree per year it could save our planet.
THANK YOU