Environment Pollution

Present Now Days Every man wants to Luxury life So Every man had an Own Vehicle it's Type Like a car ,Bus,Bike like etc..Money Increases then Every Person Life Style Changed.And also Some People Build for Houses Cutting the Tress and Forests.Our Environment also changed like that one.so pollution Increases.

Present Pollution:
Last month was the hottest May in terms of global surface temperature in a historical record that extends back 130 years, according to NASA, and with an El Niño forecast for the end of the year, we could see more records fall.
But there are some more hopeful signs about the longer term. CO2 emissions fell by about 12% in both USA and EU between 2007 and 2012, for reasons including the global recession, rising gas use and a shift to renewable energy sources President Obama's recent announcement of pollution controls on coal-fired power generation is also an important step.But by far the most important may well be the accelerated changes in energy structure - from coal and oil to renewable, nuclear and natural gas - that China is seeking to bring about, in response to really serious levels of air pollution in most of China's cities. I and other colleagues recently discussed the issue in an article in Nature Climate Change.

IN INDIA:

Delhi has the highest level of the airborne particulate matter, PM2.5 considered most harmful to health, with 153 micrograms. Not far behind is another Indian city, Patna with 149 micrograms. These figures are six times what the WHO considers a "safe" limit -- which is 25 micrograms.Half of the top 20 cities in the world with the highest levels of PM2.5 were in India, according to the pollution data released by the WHO, which included 1,600 cities. Other cities with high levels were located in Pakistan and Bangladesh.

PM2.5 refers to the diameter measured in microns of particulates such as ammonia, carbon, nitrates and sulfate -- which are small enough to pass into the bloodstream and cause diseases such as emphysema and cancer.The WHO data echoes an earlier study this year which found that air pollution in New Delhi is now worse than Beijing.

No Chinese cities ranked in the top 20 most polluted cities, despite thick, gray smog filling its cities and millions of residents commuting behind surgical masks. Beijing reported 56 micrograms of PM2.5. This year, Chinese leaders have declared "war on pollution."Beijing's emergency measures amid fog of pollution.Delhi has been described as having weak enforcement of pollution controls by India's Center for Science and Environment, a public interest group "Originally designed as compact entities to reduce the length of travel ... (Indian cities) are becoming victims of killer pollution, congestion ... and a crippling car-dependent infrastructure," according to the group.It may seem an academic argument when you're wiping sulphate-saturated tears from your eyes or coughing up a lung while sightseeing at the Forbidden City or the Red Fort, but a new study says New Delhi has outstripped Beijing and gained the inglorious title of the world's most polluted major city.At its worst, air pollution in New Delhi this winter was 60 times higher than the level considered safe, the research from India's Center for Science and Environment (CSE) reveals.The most harmful airborne pollutants, categorized innocuously enough as PM2.5, averaged 575 micrograms per cubic meter in the Indian capital from November to January.That compared with a -- still dangerous -- concentration of 400 micrograms at peak levels in Beijing over the same period.

.Air pollution has spread by increasing reliance on fossil fuels, coal-fired power plants, cars and the use of biomass for cooking and heating.Cities with the lowest level of pollution were located in Canada, the United States, Finland, Iceland and Sweden.

the ozone that shields Earth from the Sun's radiation is found in the stratosphere, a layer of the upper atmosphere found 9–30 mi above ground. This ozone layer is maintained as follows: the action of ultraviolet light breaks O ₂ molecules into atoms of elemental oxygen (O). The elemental oxygen then attaches to other O ₂ molecules to form O ₃ . When it absorbs ultraviolet radiation that would otherwise reach Earth, ozone is, in turn, broken down into O ₂ + O. The elemental oxygen generated then finds another O ₂ molecule to become O ₃ once again.

In 1974, chemists F. Sherwood Rowland and Mario J. Molina realized that chlorine from chlorofluorocarbon (CFC) molecules was capable of breaking down ozone in the stratosphere. In time, evidence began to accumulate that the ozone layer was indeed being broken apart by these industrial chemicals, and to a lesser extent by nitrogen oxide emissions from jet airplanes as well as hydrogen chloride emissions from large volcanic eruptions.

When released into the environment, CFCs slowly rise into the upper atmosphere, where they are broken apart by solar radiation. This releases chlorine atoms that act as catalysts, breaking up molecules of ozone by stripping away one of their oxygen atoms. The chlorine atoms, unaltered by the reaction, are each capable of destroying ozone molecules repeatedly. Without a sufficient quantity of ozone to block its way, ultraviolet radiation from the Sun passes through the upper atmosphere and reaches Earth's surface.

When damage to the ozone layer first became apparent in 1974, propellants in aerosol spray cans were a major source of CFC emissions, and CFC aerosols were banned in the United States in 1978. Production of CFC-12 (also known by R-12 or the trade name Freon), used in cooling and refrigeration, ended in 1995, although use is allowed until supplies are depleted. However, CFCs have since remained in widespread use in thermal insulation, as cleaning solvents, and as foaming agents in plastics, resulting in continued and accelerating depletion of stratospheric ozone.The most dramatic evidence of the destruction of the ozone layer has occurred over Antarctica, where a massive "hole" in the ozone layer appears each winter and spring, apparently exacerbated by the area's unique and violent climatological conditions. The destruction of ozone molecules begins during the long, completely dark, and extremely cold Antarctic winter, when swirling winds and ice clouds begin to form in the lower stratosphere. This ice reacts with chlorine compounds in the stratosphere (such as hydrogen chloride and chlorine nitrate) that come from the breakdown of CFCs, creating molecules of chlorine.

When spring returns in August and September, a seasonal vortex—a rotating air mass—causes the ozone to mix with certain chemicals in the presence of sunlight. This helps break down the chlorine molecules into chlorine atoms, which, in turn, react with and break up the molecules of ozone. A single chlorine, bromine, or nitrogen molecule can break up literally thousands of ozone molecules.

During December, the ozone-depleted air can move out of the Antarctic area, as happened in 1987, when levels of ozone over southern Australia and New Zealand sank by 10% over a three-week period, causing as much as a 20% increase in ultraviolet radiation reaching Earth. This may have been responsible for a reported increase in skin cancers and damage to some food crops.

The seasonal hole in the ozone layer over Antarctica has been monitored by scientists at the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center outside Washington, D.C. NASA's NIMBUS-7 satellite first discovered drastically reduced ozone levels over the Southern Hemisphere in 1985, and measurements are also being conducted with instruments on aircraft and balloons. Some of the data that has been gathered is alarming.

In October 1987, ozone levels within the Antarctic ozone hole were found to be 45% below normal, and similar reductions occurred in October 1989. A 1988 study revealed that since 1969, ozone levels had declined by 2% worldwide, and by as much as 3% or more over highly populated areas of North America, Europe, South America, Australia, and New Zealand.

In September 1992, the NIMBUS-7 satellite found that the depleted ozone area over the southern polar region had grown 15% from the previous year, to a size three times larger than the area of the United States, and was 80% thinner than usual. The ozone hole over Antarctica was measured at approximately 8.9 million mi ² , as compared to its usual size of 6.5 million mi ² . The contiguous 48 states are, by comparison, about 3 million mi ² , and all of North America covers 9.4 million mi ² . Researchers attributed the increased thinning not only to industrial chemicals but also to the 1991 volcanic eruptions of Mount Pinatubo in the Philippines and Mount Hudson in Chile, which emitted large amounts of sulfur dioxide into the atmosphere.ozone layer depletion is spreading at an alarming rate. In the 1980s, scientists discovered that an ozone hole was also appearing over the Arctic region in the late winter months, and concern was expressed that similar thinning might begin to occur over, and threaten, heavily populated areas of the globe. These fears were confirmed in April 1991, when the Environmental Protection Agency (EPA) announced that satellite measurements had recorded an ominous decrease in atmospheric ozone, amounting to an average of 5% over the mid-latitudes (including the United States), almost double the loss previously thought to be occurring.

The data showed that ozone levels measured in the late fall, winter, and early spring over large areas of the United States, Europe, and the mid-latitudes of the Northern and Southern Hemispheres had dropped by 4–6% over the last decade—twice the amount estimated in earlier years. The greatest area of ozone thinning in the United States was found north of a line stretching from Philadelphia to Denver to Reno, Nevada. One of the most alarming aspects of the new findings was that the ozone depletion was continuing into April and May, a time when people spend more time outside, and crops are beginning to sprout, making both more vulnerable to ultraviolet radiation.

The new findings led the EPA to project that over the next 50 years, thinning of the ozone layer could cause Americans to suffer some 12 million cases of skin cancer, 200,000 of which would be fatal. Several years earlier, the agency had calculated that over the next century, there could be an additional 155 million cases of skin cancers and 3.2 million deaths if the ozone layer continued to thin at the then current rate. Another EPA projection made in the 1980s was that the increase in radiation could cause Americans to suffer 40 million cases of skin cancer and 800,000 deaths in the following 88 years, plus some 12 million eye cataracts.

s evidence of the critical threats posed by ozone layer depletion has increased, the world community has begun to take steps to address the problem. In 1987, the United States and 22 other nations signed the Montreal Protocol, agreeing, by the year 2000, to cut CFC production in half, and to phase out two ozone-destroying gases, Halon 1301 and Halon 1211. Halons are human-made bromine compounds used mainly in fire extinguishers, and can destroy ozone at a rate 10 to 40 times more rapidly than CFCs. Fortunately, these restrictions appear to already be having an impact. In 1992, it was found that the rate at which these two Halon gases were accumulating in the atmosphere had fallen significantly since 1987. The rate of increase of levels of Halon 1301 was about 8% per year during 1989–1992, about half of the average annual rate of growth over previous years. Similarly, Halon 1211 was increasing at only 3% annually, much less than the previous growth of 15% a year.

Since the Montreal Protocol, other international treaties have been signed limiting the production and use of ozone-destroying chemicals. When alarming new evidence on the destruction of stratospheric ozone became available in 1988, the world's industrialized nations convened a series of conferences to plan remedial action. In March 1989, the 12-member European Economic Community (EEC) announced plans to end the use of CFCs by the turn of the century, and the United States agreed to join in the ban. A week later, 123 nations met in London to discuss ways to speed the CFC phase-out. The industrial nations agreed to cut their own domestic CFC production in half, while continuing to allow exports of CFCs, in order to accommodate Third World nations.

The large industrial nations, which have created the CFC problem, are now much more willing to take effective action to ban the compounds than are many developing nations, such as India and China. The latter nations resist restrictions on CFCs on the grounds that the chemicals are necessary for their own economic development.

After the meeting in London, leaders and representatives from 24 countries met in an environmental summit at The Hague, Netherlands, and agreed that the United Nations' authority to protect the world's ozone layer should be strengthened.

In May 1989, members of the EEC and 81 other nations that had signed the 1987 Montreal Protocol decided at a meeting in Helsinki, Finland, to try to achieve a total phase-out of CFCs by the year 2000, as well as phase-outs as soon as possible of other ozone-damaging chemicals like carbon tetrachloride, halons, and methyl chloroform. In London in June 1990, most of the Montreal Protocol's signatory nations formally adopted a deadline of the year 2000 for industrial nations to phase out the major ozone-destroying chemicals, with 2010 being the goal for developing countries.

Finally, in November 1992, 87 nations meeting in Copenhagen, Denmark, decided to strengthen the action agreed to under the Montreal Protocol and move up the phase-out deadline from 2000 to January 1, 1996 for CFCs, and to January 1, 1994 for halons. A timetable was also agreed to for eliminating hydrochlorofluorocarbons (HCFCs) by the year 2030. HCFCs are being used as substitutes for CFCs even though they also deplete ozone, albeit on a far lesser scale than CFCs. The conference failed to ban the production of the pesticide methyl bromide, which may account for 15% of ozone depletion by the year 2000, but did freeze production at 1991 levels.

Environmentalists were disappointed that stronger action was not taken to protect the ozone layer. But Environmental Protection Agency (EPA) Administrator William K. Reilly, who headed the United States delegation, estimated that the reductions agreed to could, by the year 2075, prevent a million cases of cancer and 20,000 deaths.

Although the restrictions apply to developed nations, which produce most of the ozone-damaging chemicals, it was also agreed to consider moving up a phase-out of such compounds by developing nations from 2010 to 1995. A month after the Copenhagen conference, the nations of the European Community agreed to push bans on the use of CFCs and carbon tetrachloride to 1995 and to cut CFC emissions by 85% by the end of 1993.

The private sector has also taken action to reduce CFC production. The world's largest manufacturer of the chemicals, DuPont Chemical Company, announced in 1988 that it was working on a variety of substitutes for CFCs, would phase out production of them by 1996, and would partially replace them with HCFCs. Environmentalists charge that DuPont has been moving too slowly to eliminate production of these chemicals.

There are many ways that individuals can help reduce the release of CFCs into the atmosphere, mainly by avoiding products that contain or are made from CFCs, and by recycling CFCs whenever possible. Although CFCs have not generally been used in spray cans in the United States since 1978, they are still used in many consumer and industrial products, such as styrofoam. Other products manufactured using CFCs include solvents and cleaning liquids used on electrical equipment, polystyrene foam products, and fire extinguishers that use halons.

Refrigerants in cars and home air conditioning units that still use CFCs must be poured into closed containers to be cleaned or recycled, or they will evaporate into the atmosphere. Using foam insulation to seal homes also releases CFCs. Many alternatives to foam insulation exist, such as cellulose fiber, gypsum, fiberboard, and fiberglass.

Unfortunately, whatever steps are taken in the next few years, the problem of ozone layer depletion will continue even after the release of ozone-destroying chemicals is limited or halted. It takes six to eight years for some of these compounds to reach the upper atmosphere, and once there, they will destroy ozone for another 20–25 years. Thus, even if all emissions of destructive chemicals were stopped, compounds already released would continue to damage the ozone layer for another quarter century.