never earth

8/14/2019 Never Earth

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NEVERBEFOREHASTHE EARTHBEENSOTHREATENEDTHAN IT ISTODAY. THE

EARTH HAS SURVIVED COUNTLESS NATURAL DISASTERS SUCH AS VOLCANIC

ERUPTIONS AND VIOLENT EARTHQUAKES, BUT EVEN THEN, NONE OF THESE

CATASTROPHES HAS HAD SUCH A GREAT IMPACT ON THE EARTH AS THE

ACTIVITIES OUT BY HUMAN THEMSELVES. IN THEIR ATTEMPT TO FULFIL THE

GROWING NEEDS OF AN EVER-INCREASING POPULATION, MANKIND DESTROYS

NATURAL HABITATS THAT HOUSE MILLIONS OF FLORA AND FAUNASPECIES AND

AT THE SAME TIME POLLUTES THE ENVIRONMENT. HUMAN ACTIVITIES OFTEN

HAVE A WIDESPREAD IMPACT ON ECOSYSTEMS. WITH GREATER ADVANCES INMEDICINE, MODERN FARMING TECHNIQUES AND BETTER INFRASTRUCTURE, THE

WORLDS POPULATION HAS GROWN TO OVER SIX BILLION TODAY. CONFLICTS

THEREFORE ARISE BETWEEN FULFILLING IMMEDIATE HUMAN NEEDS AND THE

NECESSITY TO PROTECT THE ENVIRONMENT FROM LONG-TERM DAMAGE. MANY

OFTHEPROBLEMSRELATEDTOTHEENVIRONMENTARETHERESULTSOFHUMAN

ACTIVITIES AND HUMAN INTERFERENCE IN THE WAY ECOSYSTEMS FUNCTION.

EVERYYEAR, VAST AREAS OF FORESTS ARE CLEARED TO PROVIDE SPACE AND

CULTIVATION.

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Air pollution is the introduction of chemicals, particulate matters, or biological materials

that cause harm or discomfort to humans or other living organisms,or damages the natural

environment, into the atmosphere. Stratospheric ozone depletion due to air pollution has

long been recognized to treat human health as well as to the Earths ecosystems. About four

percent of deaths in the United States attributed to air pollution, according to the

Environmental Science Engineering Program at the Harvard School of Public Health

Health.

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Carbon dioxide is one the main pollutants that causes air pollution. This is because,

although living beings do exhale carbon dioxide, this gas is harmful when emitted

from other sources, which are caused due to human activity. An additional release

of carbon dioxide happens due to various such activities. Carbon dioxide gas is used

in various industries such as the oil industry and the chemical industry. The

manufacturing process of most products would require the use of this gas. Thereare various human activities that add to the increased proportions of carbon dioxide

in the atmosphere. The combustion of fossil fuels and the harmful effects of

deforestation have all contributed towards the same. show that amongst the

various gasses emitted during a volcanic eruption, carbon dioxide remains to be at

least 40% of the emission. Scientists have now therefore identified carbon dioxide

as one of those elements that have contributed to global warming.

Causes of air pollution are not limited to this. The combustion of fuels in

automobiles, jet planes etc all cause the release of several primary pollutants into

the air. The burning of fossil fuels in big cities which is seen at most factories,

offices and even a large number of homes, it is no wonder that air pollution is

increasing at an alarming rate. The release of other harmful gases all adds to the

state that we see today. Although carbon dioxide plays an important role in various

other processes like photosynthesis, breathing an excess of the same also causes

harmful effects towards ones health.

The various causes of air pollution that releases harmful gases into the atmosphere

are caused due to the increasing number of power plants and manufacturing units

or industries that mostly have activities related to the burning of fuels. Besides, as

mentioned earlier, most automobiles, marine vessels, activities that involve the

burning of wood, fumes that are released from aerosol sprays, military activitiesthat involve the use of nuclear weapons, all are the numerous causes of air

pollution.

Carbon monoxide is another such gas which, although was present in the

atmosphere earlier, is now considered to be a major pollutant. An excess of the

same has a harmful effect on our system. There are many reasons why carbon

monoxide can be released into the atmosphere as a result of human activities. This

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is also produced due to any fuel burning appliance and appliances such as gas

water heaters, fireplaces, woodstoves, gas stoves, gas dryers, yard equipments as

well as automobiles, which add to the increased proportion of this gas into the

atmosphere.

Sulfur dioxide is yet another harmful pollutant that causes air pollution. Sulfurdioxide is emitted largely to the excessive burning of fossil fuels, petroleum

refineries, chemical and coal burning power plants etc. Nitrogen dioxide when

combined with sulfur dioxide can even cause a harmful reaction in the atmosphere

that can cause acid rain.

Nitrogen dioxide is one more gas that is emitted into the atmosphere as a result of

various human activities. An excess of nitrogen dioxide mainly happens due to most

power plants seen in major cities, the burning of fuels due to various motor vehicles

and other such sources, whether industrial or commercial that cause the increase in

the levels of nitrogen dioxide.

The World Health Organization states that 2.4 million people die each year from

causes directly attributable to air pollution, with 1.5 million of these deaths

attributable to indoor air pollution. "Epidemiological studies suggest that more than

500,000 Americans die each year from cardiopulmonary disease linked to breathing

fine particle air pollution. . ." A study by the University of Birmingham has shown a

strong correlation between pneumonia related deaths and air pollution from motor

vehicles. Worldwide more deaths per year are linked to air pollution than to

automobile accidents. Published in 2005 suggests that 310,000 Europeans die from

air pollution annually. Direct causes of air pollution related deaths include

aggravated asthma, bronchitis, emphysema, lung and heart diseases, andrespiratory allergies.The US EPA estimates that a proposed set of changes in diesel

engine technology (Tier 2) could result in 12,000 fewer premature mortalities,

15,000 fewer heart attacks, 6,000 fewer emergency room visits by children with

asthma, and 8,900 fewer respiratory-related hospital admissions each year in the

United States.

The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.

Leaked industrial vapors from the Union Carbide factory, belonging to Union

Carbide, Inc., U.S.A., killed more than 2,000 people outright and injured anywhere

from 150,000 to 600,000 others, some 6,000 of whom would later die from their

injuries. The United Kingdom suffered its worst air pollution event when theDecember 4Great Smog of 1952 formed over London. In six days more than 4,000

died, and 8,000 more died within the following months. An accidental leak of

anthrax spores from a biological warfare laboratory in the former USSR in 1979 near

Sverdlovsk is believed to have been the cause of hundreds of civilian deaths. The

worst single incident of air pollution to occur in the United States of America

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occurred in Donora, Pennsylvania in late October, 1948, when 20 people died and

over 7,000 were injured.

The health effects caused by air pollutants may range from subtle biochemical and

physiological changes to difficulty in breathing, wheezing, coughing and

aggravation of existing respiratory and cardiac conditions. These effects can resultin increased medication use, increased doctor or emergency room visits, more

hospital admissions and premature death. The human health effects of poor air

quality are far reaching, but principally affect the body's respiratory system and the

cardiovascular system. Individual reactions to air pollutants depend on the type of

pollutant a person is exposed to, the degree of exposure, the individual's health

status and genetics.]

A new economic study of the health impacts and associated costs of air pollution in

the Los Angeles Basin and San Joaquin Valley of Southern California shows that

more than 3800 people die prematurely (approximately 14 years earlier than

normal) each year because air pollution levels violate federal standards. Thenumber of annual premature deaths is considerably higher than the fatalities

related to auto collisions in the same area, which average fewer than 2,000 per year

.

Diesel exhaust (DE) is a major contributor to combustion derived particulate matter

air pollution. In several human experimental studies, using a well validated

exposure chamber setup, DE has been linked to acute vascular dysfunction and

increased thrombus formation. This serves as a plausible mechanistic link between

the previously described association between particulate matter air pollution and

increased cardiovascular morbidity and mortality.

Water pollution is a major problem in the global context. It has been suggested that

it is the leading worldwide cause of deaths and diseases, and that it accounts for

the deaths of more than 14,000 people daily.In addition to the acute problems of

water pollution in developing countries, industrialized countries continue to struggle

with pollution problems as well. In the most recent national report on water quality

in the United States, 45 percent of assessed streammiles, 47 percent of assessed

lake acres, and 32 percent of assessed bay and estuarinesquare miles were

classified as polluted.Water is typically referred to as polluted when it is impaired by

anthropogenic contaminants and either does not support a human use, like serving

as drinking water, and/or undergoes a marked shift in its ability to support its

constituent biotic communities, such as fish. Natural phenomena such as volcanoes,

algae blooms, storms, and earthquakes also cause major changes in water quality

and the ecological status of water. Water pollution has many causes and

characteristics.Surface water and groundwater have often been studied and

managed as separate resources, although they are interelated. Sources of surface

water pollution are generally grouped into two categories based on their origin.Point

source pollution refers to contaminants that enter a waterway through a discrete

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conveyance, such as a pipe or ditch. Examples of sources in this category include

discharges from a sewage treatment plant, a factory, or a city storm drain. The U.S.

Clean Water Act (CWA) defines point source for regulatory enforcement

purposes.Non-point source (NPS) pollution refers to diffuse contamination that does

not originate from a single discrete source. NPS pollution is often a cumulative

effect of small amounts of contaminants gathered from a large area. Nutrient runoffin stormwater from "sheet flow" over an agricultural field or a forest are sometimes

cited as examples of NPS pollution.Contaminated stormwater washed off ofparking

lots, roads and highways, called urban runoff, is sometimes included under the

category of NPS pollution. However, this runoff is typically channeled into storm

drain systems and discharged through pipes to local surface waters, and is a point

source. The CWA definition of point source was amended in 1987 to include

municipal storm sewer systems, as well as industrial stormwater, such as from

construction sites.Interactions between groundwater and surface water are

complex. Consequently, groundwater pollution, sometimes referred to as

groundwater contamination, is not as easily classified as surface water pollution. By

its very nature, groundwater aquifers are susceptible to contamination from sources

that may not directly affect surface water bodies, and the distinction of point vs.

nonpoint source may be irrelevant. A spill of a chemical contaminant on soil, located

away from a surface water body, may not necessarily create point source or non-

point source pollution, but nonetheless may contaminate the aquifer below.

Analysis of groundwater contamination may focus on soil characteristics and

hydrology, as well as the nature of the contaminant itself.

The specific contaminants leading to pollution in water include a wide spectrum of

chemicals, pathogens, and physical or sensory changes such as elevated

temperature and discoloration. While many of the chemicals and substances that

are regulated may be naturally occurring (calcium, sodium, iron, manganese, etc.)

the concentration is often the key in determining what is a natural component of

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water, and what is a contaminant.Oxygen-depleting substances may be natural

materials, such as plant matter (e.g. leaves and grass) as well as man-made

chemicals. Other natural and anthropogenic substances may cause turbidity

(cloudiness) which blocks light and disrupts plant growth, and clogs the gills of

some fish species.Many of the chemical substances are toxic. Pathogens can

produce waterborne diseases in either human or animal hosts. Alteration of water'sphysical chemistry include acidity (change in pH), electrical conductivity,

temperature, and eutrophication. Eutrophication is the fertilization ofsurface water

by nutrients that were previously scarce.A manhole cover blown off by a sanitary

sewer overflow.Coliform bacteria are a commonly-used bacterial indicator of water

pollution, although not an actual cause of disease. Other microorganisms

sometimes found in surface waters which have caused human health problems

include:

Cryptosporidium parvum

Giardia lamblia

Salmonella

Novovirus and other viruses

Parasitic worms (helminths).[8][9]

High levels of pathogens may result from inadequately treated sewage discharges.[10] This can be caused by a sewage plant designed with less than secondary

treatment (more typical in less-developed countries). In developed countries, older

cities with aging infrastructure may have leaky sewage collection systems (pipes,

pumps, valves), which can cause sanitary sewer overflows. Some cities also have

combined sewers, which may discharge untreated sewage during rain

storms.Pathogen discharges may also be caused by poorly-managed livestockoperations.Contaminants may include organic and inorganic substances.

Organic water pollutants include:

Detergents

Disinfection by-products found in chemically disinfecteddrinking water, such as

chloroform

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Food processing waste, which can include oxygen-demanding substances, fats and

grease

Insecticides and herbicides, a huge range oforganohalides and other chemical

compounds

Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil)

and lubricants (motor oil), and fuel combustion byproducts, from stormwater

runoff[12]

Tree and brush debris from logging operations

Volatile organic compounds (VOCs), such as industrial solvents, from improper

storage. Chlorinated solvents, which are dense non-aqueous phase liquids

(DNAPLs), may fall to the bottom of reservoirs, since they don't mix well with water

and are denser.

Various chemical compounds found in personal hygiene and cosmetic products

Inorganic water pollutants include:

Acidity caused by industrial discharges (especially sulfur dioxide from power plants)

Ammonia from food processing waste

Chemical waste as industrial by-products

Fertilizers containing nutrients--nitrates and phosphates--which are found in

stormwater runoff from agriculture, as well as commercial and residential use[12]

Heavy metals from motor vehicles (via urban stormwater runoff)[12][13] and acid

mine drainage

Silt (sediment) in runoff from construction sites, logging, slash and burn practices or

land clearing sites

Macroscopic pollution--large visible items polluting the water--may be termed

"floatables" in an urban stormwater context, or marine debris when found on theopen seas, and can include such items as:

Trash (e.g. paper, plastic, or food waste) discarded by people on the ground, and

that are washed by rainfall into storm drains and eventually discharged into surface

waters

Nurdles, small ubiquitous waterborne plastic pellets

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Shipwrecks, large derelict ships

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There are various effects of water pollution.

Spread of disease: Drinking polluted water can cause

cholera or typhoid infections, along with diarrhea.

Affects body organs: The consumption of highly

contaminated water can cause injury to the heart and

kidneys.

Harms the food chain: Toxins within water can harm

aquatic organisms, thus breaking a link in the food chain.

Causes algae in water: Urea, animal manure and vegetable

peelings are food for algae. Algae grow according to how

much waste is in a water source. Bacteria feed off the

algae, decreasing the amount of oxygen in the water. The

decreased oxygen causes harm to other organisms living

in the water.

Flooding: The erosion of soil into waterways causesflooding, especially with heavy rainfall.

Harms animals: Birds that get into oil-contaminated water

die from exposure to cold water and air due to feather

damage. Other animals are affected when they eat dead

fish in contaminated streams.

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The effects of water pollution are not always immediate.

They are not always seen at the point of contamination.

They are sometimes never known by the person

responsible for the pollution. However, water pollution

has a huge impact on our lives. With knowledge,consideration and preparation, water pollution can be

decreased. It doesn't take much effort -- just a little

thought.

The broadest definition of thermal pollution is the

degradation of water quality by any process that changes

ambient water temperature. Thermal pollution is usually

associated with increases of water temperatures in a

stream, lake, or ocean due to the discharge of heated

water from industrial processes, such as the generation of

electricity. Increases in ambient water temperature also

occur in streams where shading vegetation along the

banks is removed or where sediments have made the

water more turbid. Both of these effects allow more

energy from the sun to be absorbed by the water and

thereby increase its temperature. There are also

situations in which the effects of colder-than-normal water

temperatures may be observed. For example, the

discharge of cold bottom water from deep-water

reservoirs behind large dams has changed thedownstream biological communities in systems such as

the Colorado River.

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The production of energy from a fuel source can be direct, such as the burning of

wood in a fireplace to create heat, or by the conversion of heat energy into

mechanical energy by the use of a heat engine. Examples of heat engines include

steam engines, turbines, and internal combustion engines. Heat engines work on

the principal of heating and pressuring a fluid, the performance of mechanical work,

and the rejection of unused or waste heat to a sink. Heat engines can only convert

30 to 40 percent of the available input energy in the fuel source into mechanical

energy, and the highest efficiencies are obtained when the input temperature is ashigh as possible and the sink temperature is as low as possible. Water is a very

efficient and economical sink for heat engines and it is commonly used in electrical

generating stations.

The waste heat from electrical generating stations is transferred to cooling water

obtained from local water bodies such as a river, lake, or ocean. Large amounts of

water are used to keep the sink temperature as low as possible to maintain a high

thermal efficiency. The San Onofre Nuclear Generating Station between Los Angeles

and San Diego, California, for example, has two main reactors that have a total

operating capacity of 2,200 megawatts (MW). These reactors circulate a total of

2,400 million gallons per day (MGD) of ocean water at a flow rate of 830,000 gallonsper minute for each unit. The cooling water enters the station from two intake

structures located 3,000 feet offshore in water 32 feet deep. The water is heated to

approximately 19F above ambient as it flows through the condensers and is

discharged back into the ocean through a series of diffuser-type discharges that

have a series of sixty-three exit pipes spread over a distance of 2,450 feet. The

discharge water is rapidly mixed with ambient seawater by the diffusers and the

average rise in temperature after mixing is less than 2F.

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The primary effects of thermal pollution are direct thermal shock, changes in

dissolved oxygen, and the redistribution of organisms in the local community.

Because water can absorb thermal energy with only small changes in temperature,

most aquatic organisms have developed enzyme systems that operate in only

narrow ranges of temperature. These stenothermic organisms can be killed bysudden temperature changes that are beyond the tolerance limits of their metabolic

systems. The cooling water discharges of power plants are designed to minimize

heat effects on local fish communities. However, periodic heat treatments used to

keep the cooling system clear of fouling organisms that clog the intake pipes can

cause fish mortality. A heat treatment reverses the flow and increases the

temperature of the discharge to kill the mussels and other fouling organisms in the

intake pipes. Southern California Edison had developed a "fish-chase" procedure in

which the water temperature of the heat treatment is increased gradually, instead

of rapidly, to drive fish away from the intake pipes before the temperature reaches

lethal levels. The fish chase procedure has significantly reduced fish kills related toheat treatments.

Small chronic changes in temperature can also adversely affect the reproductive

systems of these organisms and also make them more susceptible to disease. Cold

water contains more oxygen than hot water so increases in temperature also

decrease the oxygen-carrying capacity of water. In addition, raising the water

temperature increases the decomposition rate of organic matter in water, which

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also depletes dissolved oxygen. These decreases in the oxygen content of the water

occur at the same time that the metabolic rates of the aquatic organisms, which are

dependent on a sufficient oxygen supply, are rising because of the increasing

temperature.

The composition and diversity of communities in the vicinity of cooling waterdischarges from power plants can be adversely affected by the direct mortality of

organisms or movement of organisms away from unfavorable temperature or

oxygen environments. A nuclear power-generating station on Nanwan Bay in

Taiwan caused bleaching of corals in the vicinity of the discharge channel when the

plant first began operation in 1988. Studies of the coralAcropora grandis in 1988

showed that the coral was bleached within two days of exposure to temperatures of

91.4F. In 1990 samples of coral taken from the same area did not start bleaching

until six days after exposure to the same temperature. It appears that the

thermotolerance of these corals was enhanced by the production of heat-shock

proteins that help to protect many organisms from potentially damaging changes

in temperature. The populations of some species can also be enhanced by the

presence of cooling water discharges. The only large population of sea turtles in

California, for example, is found in the southern portion of San Diego Bay near the

discharge of an electrical generating station.

Noise Pollution or Sound Pollution, exposure of people or animals to levels ofsound

that are annoying, stressful, or damaging to the ears. Although loud and frightening

sounds are part of nature, only in recent centuries has much of the world become

urban, industrial, and chronically noisy.

Sound intensity is measured in units called decibels. The decibel scale is logarithmic

and climbs steeply: An increase of about three decibels is a doubling of sound

volume. In the wilderness, a typical sound level would be 35 decibels. Speech runs

65 to 70 decibels; heavy traffic generates 90 decibels. By 140 decibels, soundbecomes painful to the human ear, but ill effects, including hearing loss, set in at

much lower levels.

Most noise pollution comes from machines, especially automobiles, trucks, and

aircraft. Construction equipment, farm machines, and the din of machinery inside

factories can be dangerously loud. Some home appliances, shop tools, lawnmowers,

and leaf blowers can also be noisy, as are guns, firecrackers, and some toys. Even

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music, when played at very high volume, particularly through personal headphones,

is as damaging to the ears as a roaring chain saw.

Hearing loss can also occur in the workplace, where individuals may be unable to

avoid loud sounds and where exposure may continue for years. Factory workers,

construction workers, farmers, military personnel, police officers, firefighters, andmusicians all have reason to be concerned about their occupational exposure to

noise.

While there are many different sources of noise pollution, there are some main

culprits that have been researched and found to have a negative impact on health.

They include the following:

AirplanesIts been well-documented that noise pollution from airplanes has a

significant negative impact on the health and wellbeing of those who live close to

airports. This can include heart disease, high blood pressure and chronic stress.

Cars--One of the complaints of those who live in big cities or on busy streets is the

disruption from the sounds of traffic. Interestingly, though, even low levels of traffic

noise can be damaging to people, and traffic noise is one of the most commonly

experienced contributors to noise pollution.

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Workplace NoiseMost of us may think of loud assembly lines or construction sites

when we think of noise pollution in the workplace, and while these examples

definitely apply, regular offices are not immune. With more people packed into busy

office spaces, office noise is a common complaint. Co-workers who talk, drum their

fingers on the desk, or offer other distracting noises can decrease the productivity

of those around them without realizing it.

Home Sound--Many people dont think of their homes as noisy, but if theres a lot

of activity in the home, including a constantly running television, this overall noise

level can actually be a threat to concentration and a cause of stress. In fact,

children from more noisy homes do suffer ill effects from this type of sound

pollution that include less cognitive growth, delayed language skills, increased

anxiety, and impaired resilience, according to a Purdue University professor in a

related press release.

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Many studies have been conducted to study the effects of noise pollution on health

and wellness, and the results have shown that noise pollution can negatively impact

you in the following ways:

Productivity: We all know that noise can be distracting, and research proves this.

One study examined children exposed to airport noise and found that their readingability and long-term memory was impaired. Those working in noisy office

environments have also been found to be less cognitively motivated, and to have

higher stress levels, according to a Cornell University study.

Health: Perhaps the most serious problem created by sound pollution is the impact

it has on our health. Because sound pollution can trigger the bodys stress

response, one of its major health effects is chronic stress and the high levels of

stress hormones that go with it. As a result, noise pollution has also been linked

with health problems such as heart disease, high blood pressure, and stroke. Its

also been linked with musculoskeletal problems, as a Cornell University study on

office noise found that those working in noisy office environments can also be lesslikely to ergonomically adjust their workstations for comfort, which can contribute to

physical problems. Noise pollution can also impact sleep quality by preventing sleep

and disrupting sleep cycles. And, perhaps most significantly, because chronic stress

can lower your immunity to all disease, noise pollution is a general threat to health

and wellness.

Greenhouse Effect, the capacity of certain gases in the atmosphere to trap heat

emitted from Earths surface, thereby insulating and warming the planet. Without

the thermal blanketing of the natural greenhouse effect, Earths climate would be

about 33C (about 59F) coolertoo cold for most living organisms to survive.

The greenhouse effect has warmed Earth for over 4 billion years. Now scientists are

growing increasingly concerned that human activities may be modifying this natural

process, with potentially dangerous consequences. Since the advent of the

Industrial Revolution in the 1700s, humans have devised many inventions that burn

fossil fuels such as coal, oil, and natural gas. Burning these fossil fuels, as well as

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other activities such as clearing land for agriculture or urban settlements, releases

some of the same gases that trap heat in the atmosphere, including carbon dioxide,

methane, and nitrous oxide. These atmospheric gases have risen to levels higher

than at any time in at least the last 650,000 years. As these gases build up in the

atmosphere, they trap more heat near Earths surface, causing Earths climate to

become warmer than it would naturally.

Scientists call this unnatural heating effect global warming and blame it for an

increase in Earths surface temperature of about 0.6C (about 1F) over the last 100

years. Scientists project global temperatures to continue rising during the 21st

century. Warmer temperatures could melt parts of polar ice caps and most

mountain glaciers, causing a rise in sea level that would flood coastal regions.

Global warming could also affect weather patterns causing, among other problems,

prolonged drought or increased flooding in some of the worlds leading agricultural

regions.

Life on earth depends on energy from the sun. About 30

percent of the sunlight that beams toward Earth is deflected

by the outer atmosphere and scattered back into space. The

rest reaches the planets surface and is reflected upward again

as a type of slow-moving energy called infrared radiation.

As it rises, infrared radiation is absorbed by greenhouse

gases such as water vapor, carbon dioxide, ozone and

methane, which slows its escape from the atmosphere.

Although greenhouse gases make up only about 1 percent of

the Earths atmosphere, they regulate our climate by trapping

heat and holding it in a kind of warm-air blanket that

surrounds the planet.

This phenomenon is what scientists call the "greenhouse

effect." Without it, scientists estimate that the average

temperature on Earth would be colder by approximately 30

degrees Celsius (54 degrees Fahrenheit), far too cold to

sustain our current ecosystem.

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Heatwaves associated with land temperature increase and

thousands of people will die through future heatwaves. (In the

2003 heatwaves in France over 20,000 people died).

Droughts will become more prolonged and be even moredevastating than anything we have experienced. This is

because higher temperatures evaporate water from the land,

which will also give rise to more wildfires.Agriculture and food

crops will be devastated in some regions and diseases like

malaria and dengue fever will increase as conditions

favourable to these diseases spread.

Higher ocean temperatures increase the power in cyclones and

hurricanes, (stimulating more tornadoes ) and we will see ahigher frequency of severe storms (like Hurricane Katrina)and

associated flooding that will do extraordinary damage to

infrastructure, and destroy houses, towns and villages. This is

already driving up insurance costs.

Rising sea levels will displace millions of people, (already on

some Islands people are being moved off due to rising seas)

and the geography of the land will change dramatically, with

millions needing to be relocated along with loss of buildings.

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Ozone Layer, a region of the atmosphere from 19 to 48 km

(12 to 30 mi) above Earth's surface. Ozone concentrations

of up to 10 parts per million occur in the ozone layer. The

ozone forms there by the action of sunlight on oxygen.

This action has been taking place for many millions ofyears, but naturally occurring nitrogen compounds in the

atmosphere apparently have kept the ozone concentration

at a fairly stable level.

The ozone layer of the atmosphere protects life on Earth

by absorbing harmful ultraviolet radiation from the Sun. If

all the ultraviolet radiation given off by the Sun were

allowed to reach the surface of Earth, most of the life onEarths surface would probably be destroyed. Short

wavelengths of ultraviolet radiation, such as UV-A, B, and

C, are damaging to the cell structure of living organisms.

Fortunately, the ozone layer absorbs almost all of the

short-wavelength ultraviolet radiation and much of the

long-wavelength ultraviolet radiation given off by the Sun.

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The Antarctic ozone hole is an area of the Antarctic stratosphere in which the recentozone levels have dropped to as low as 33% of their pre-1975 values. The ozone

hole occurs during the Antarctic spring, from September to early December, as

strong westerly winds start to circulate around the continent and create an

atmospheric container. Within this polar vortex, over 50% of the lower stratospheric

ozone is destroyed during the Antarctic spring.[15]

As explained above, the overall cause of ozone depletion is the presence of

chlorine-containing source gases (primarily CFCs and related halocarbons). In the

presence of UV light, these gases dissociate, releasing chlorine atoms, which then

go on to catalyze ozone destruction. The Cl-catalyzed ozone depletion can take

place in the gas phase, but it is dramatically enhanced in the presence ofpolar

stratospheric clouds (PSCs).[16]

These polar stratospheric clouds form during winter, in the extreme cold. Polar

winters are dark, consisting of 3 months without solar radiation (sunlight). Not only

lack of sunlight contributes to a decrease in temperature but also the polar vortex

traps and chills air. Temperatures hover around or below -80 C. These low

temperatures form cloud particles and are composed of either nitric acid (Type I

PSC) or ice (Type II PSC). Both types provide surfaces for chemical reactions that

lead to ozone destruction.

The photochemical processes involved are complex but well understood. The key

observation is that, ordinarily, most of the chlorine in the stratosphere resides in

stable "reservoir" compounds, primarily hydrochloric acid (HCl) and chlorine nitrate

(ClONO2). During the Antarctic winter and spring, however, reactions on the surface

of the polar stratospheric cloud particles convert these "reservoir" compounds into

reactive free radicals (Cl and ClO). The clouds can also remove NO2 from the

atmosphere by converting it to nitric acid, which prevents the newly formed ClO

from being converted back into ClONO2.

The role of sunlight in ozone depletion is the reason why the Antarctic ozone

depletion is greatest during spring. During winter, even though PSCs are at their

most abundant, there is no light over the pole to drive the chemical reactions.

During the spring, however, the sun comes out, providing energy to drive

photochemical reactions, and melt the polar stratospheric clouds, releasing the

trapped compounds.

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Most of the ozone that is destroyed is in the lower stratosphere, in contrast to the

much smaller ozone depletion through homogeneous gas phase reactions, which

occurs primarily in the upper stratosphere.

Warming temperatures near the end of spring break up the vortex around mid-

December. As warm, ozone-rich air flows in from lower latitudes, the PSCs aredestroyed, the ozone depletion process shuts down, and the ozone hole closes.

Effects of ozone layer depletion on humans

UVB (the higher energy UV radiation absorbed by ozone) is generally accepted to be

a contributory factor to skin cancer. In addition, increased surface UV leads to

increased tropospheric ozone, which is a health risk to humans.The increased

surface UV also represents an increase in the vitamin D synthetic capacity of thesunlight.

The cancer preventive effects of vitamin D represent a possible beneficial effect of

ozone depletion. In terms of health costs, the possible benefits of increased UV

irradiance may outweigh the burden.

1. Basal and Squamous Cell Carcinomas -- The most common forms of skin

cancer in humans, basal and squamous cell carcinomas, have been strongly linked

to UVB exposure. The mechanism by which UVB induces these cancers is well

understood absorption of UVB radiation causes the pyrimidine bases in the DNA

molecule to form dimers, resulting in transcription errors when the DNA replicates.These cancers are relatively mild and rarely fatal, although the treatment of

squamous cell carcinoma sometimes requires extensive reconstructive surgery. By

combining epidemiological data with results of animal studies, scientists have

estimated that a one percent decrease in stratospheric ozone would increase the

incidence of these cancers by 2%.

2. Malignant Melanoma -- Another form of skin cancer, malignant melanoma, is

much less common but far more dangerous, being lethal in about 15% - 20% of the

cases diagnosed. The relationship between malignant melanoma and ultraviolet

exposure is not yet well understood, but it appears that both UVB and UVA are

involved. Experiments on fish suggest that 90 to 95% of malignant melanomas maybe due to UVA and visible radiationwhereas experiments on opossums suggest a

larger role for UVB.Because of this uncertainty, it is difficult to estimate the impact

of ozone depletion on melanoma incidence. One study showed that a 10% increase

in UVB radiation was associated with a 19% increase in melanomas for men and

16% for women. A study of people in Punta Arenas, at the southern tip ofChile,

showed a 56% increase in melanoma and a 46% increase in nonmelanoma skin

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cancer over a period of seven years, along with decreased ozone and increased UVB

levels.

3. Cortical Cataracts -- Studies are suggestive of an association between ocular

cortical cataracts and UV-B exposure, using crude approximations of exposure and

various cataract assessment techniques. A detailed assessment of ocular exposureto UV-B was carried out in a study on Chesapeake Bay Watermen, where increases

in average annual ocular exposure were associated with increasing risk of cortical

opacity In this highly exposed group of predominantly white males, the evidence

linking cortical opacities to sunlight exposure was the strongest to date. However,

subsequent data from a population-based study in Beaver Dam, WI suggested the

risk may be confined to men. In the Beaver Dam study, the exposures among

women were lower than exposures among men, and no association was

seen.Moreover, there were no data linking sunlight exposure to risk of cataract in

African Americans, although other eye diseases have different prevalences among

the different racial groups, and cortical opacity appears to be higher in African

Americans compared with whites.

4. Increased Tropospheric Ozone -- Increased surface UV leads to increased

tropospheric ozone. Ground-level ozone is generally recognized to be a health risk,

as ozone is toxic due to its strong oxidant properties. At this time, ozone at ground

level is produced mainly by the action of UV radiation on combustion gases from

vehicle exhausts.

Effects on crops

An increase of UV radiation would be expected to affect crops. A number of

economically important species of plants, such as rice, depend on cyanobacteria

residing on their roots for the retention ofnitrogen. Cyanobacteria are sensitive to

UV light and they would be affected by its increase.

Effects on plankton

Research has shown a widespread extinction ofplankton 2 million years ago that

coincided with a nearby supernova. There is a difference in the orientation and

motility of planktons when excess of UV rays reach earth. Researchers speculate

that the extinction was caused by a significant weakening of the ozone layer at that

time when the radiation from the supernova produced nitrogen oxides that

catalyzed the destruction of ozone (plankton are particularly susceptible to effects

of UV light, and are vitally important to marine food webs).

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