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Introduction to Global warming

The average facade temperature of the globe has augmented more than 1 degree Fahrenheit

since 1900 and the speed of warming has been almost three folds the century long average since

1970. This increase in earths average temperature is called Global warming.

More or less all specialists studying the climate record of the earth have the same opinion now

that human actions, mainly the discharge of green house gases from smokestacks, vehicles, and

burning forests, are perhaps the leading power driving the fashion.

The gases append to the planet's normal greenhouse effect, permitting sunlight in, but stopping

some of the ensuing heat from radiating back to space. Based on the study on past climate shifts,

notes of current situations, and computer simulations, many climate scientists say that lacking of

big curbs in greenhouse gas discharges, the 21st century might see temperatures rise of about 3

to 8 degrees, climate patterns piercingly shift, ice sheets contract and seas rise several feet. With

the probable exemption of one more world war, a huge asteroid, or a fatal plague, global

warming may be the only most danger to our planet earth.

Earth has seen a violent past and has seen life forms disappearing from its surface, but that

was due to natural forces. But now, humans are creating a catastrophe known as global warming

that will wipe out all the life forms in future if it is not stopped now. Global warming definition

can be understood by following the average temperature of earths surface in the last hundred

years. An average temperature has risen dramatically since the industrial revolution clearly

showing that global warming is not a natural phenomenon but is a manmade disaster.


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To understand global warming definition one must understand clearly the

cause of global warming. Root cause of global warming is the emission of carbon dioxide due to

burning of fossil fuels. The main culprits are the power plants that burn coal to produceelectricity and in the process emit huge amounts of carbon dioxide. This carbon dioxide envelops

earth and does not allow heat of the sun to escape into the atmosphere, giving rise to the

temperature.

Thermal power plants emitting CO2


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1. Increase in temperature

The effects could be far greater than we imagine. Global warming does not occur evenly across

the world. Temperature changes have been, and will be, much more extreme in the Arctic and

Antarctic. A 5 degree Fahrenheit warming for the whole world means only 1 degree at the

equator, but 12 degrees at the poles.

Global temperatures have already risen about 0.8 degrees Celsius, or 1.4 degree Fahrenheit.

From 1961 to 2003, the global ocean temperature has risen by 0.10 C from the surface to a

depth of 700 m. The temperature of the Antarctic Southern Ocean rose by 0.17 C (0.31 F)

between the 1950s and the 1980s, nearly twice the rate for the world's oceans as a whole.

2. Increasing levels ofGreen House Gases


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Greenhouse gases:-

Greenhouse gases are the ingredients of the atmosphere that add to the greenhouse effect. Some

greenhouse gases are present naturally in the atmosphere, whereas few green house gases are a

consequence of human activity. The greenhouse gases that are present in the atmosphere

naturally include:

i. Water vaporii. Carbon dioxide

iii. Nitrous oxideiv. Methanev. Ozone.

There are a few human activities, which increase the levels of most of these naturally occurring

gases. The concentration of various green house effect gases has substantially increased in the

recent times.

Greenhouse gases, which are the major cause of global warming, trap heat in the earth's

atmosphere. Since the middle of the 19th century, human agriculture and industrialization

have dispensed an enormous quantity of these green house gases into the atmosphere, where

these have trapped enough heat to begin climate change. According to the United Nations, there

has been a rise of about 0.6 degrees Celsius during the past century. More warming is expected

to occur in the coming decades.

The main reasons for the emission of gases that are a cause of green house effect are:

(a) Burning of fossil fuel like coal in the power plants for the purpose of generation of electricity.

Fossil fuel burning leads to high emissions of carbon dioxide gas.

(b) Another green house gas is methane. Methane is more than 20 times as effectual as CO2 at

entrapping heat in the atmosphere. Methane is obtained from resources such as rice paddies,

bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world,


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rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the

organic matter in the soil decays, releasing methane to the atmosphere.

(c) Nitrous oxide, which is a colorless gas with a sweet odor, is also a green house gas. The

main sources of nitrous oxide include:

1. Nylon and nitric acid production,2. Cars with catalytic converters,3. The use of fertilizers in agriculture and4. The burning of organic matter.

A greater emission of nitrous oxides in the recent decades is leading to global warming.

(d) Another jump in the category of green house gases is in the name of hydro-flouro-carbons

and per-flouro-carbons, manmade chemicals initiated as a substitute to other chemicals that

deplete the atmosphere's protective ozone layer.


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The greenhouseeffect

y Prior to the advent of the industrial age, the concentration of CO2 in the atmosphere was about280 ppm (parts per million).

y Today its over 360 ppm. Thats an increase of about 30% in less than 300 years.

There is now more CO2 in our atmosphere than ever before in human history.

For the earth, this is an unprecedented rate of change, about 10,000 years worth of change

compressed into 100 years. And there is more CO2 in our air now than at any time since humans

evolved, more than anytime over the last million years! The earth is used to slow changes, not

fast ones. Slow changes allow the biosphere and earths species time to adjust. Quick change

may cause biological chaos and disrupt agricultural production. Carbon dioxide is critical to

controlling the earths heat balance because it absorbs infrared radiation (IR), basically heat.

y Coming to earth from the sun, visible radiation passes through the clear atmosphere and hits theearth.

y A portion of it is absorbed and re-radiated back to space as IR.y CO2 traps this IR and reflects it back to the earths surface, causing further warming.

The greenhouse effect the warming of our atmosphere relies on CO2.


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This is called the greenhouse effect. Without it, water would freeze on earth. With too much

greenhouse effect, water would boil off, leaving the surface of earth a desert. This may have

been what happened on earths neighbor, Venus. There is a delicate balance between sunlight,

CO2 concentration, and heat that we must be careful not to disrupt.

The speedy increase in greenhouse gases over the past century is a matter of worry in at least

800,000 years, according to a study of the oldest Antarctic ice core. Scientists at the British

Antarctic Survey (BAS) in Cambridge have established the fact that there have been eight cycles

of atmospheric alterations in the past 800,000 years when green house gases like carbon dioxide

and methane have risen to high levels. Each time, the earth also had a comparatively high

temperatures linked with warm; inter glacial periods, which were most certainly associated with

levels of carbon dioxide and probably methane in the atmosphere.

However, present levels of green house gases are much higher than everything seen during those

previous warm periods. Although much is being done to reduce the emission of these green

house gases, but the efforts are still not enough. An international agreement called the Kyoto

Protocol has been made among the various nations to cut down the emission of these gases.

There is a dire need that each one understands the ill effects of these green house gases and does

the need full.

3. Polar ice caps melting


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The ice caps melting is a four-pronged danger.

First, it will raise sea levels. There are 5,773,000 cubic miles of water in ice caps, glaciers, and

permanent snow. According to the National Snow and Ice Data Center, if all glaciers melted

today the seas would rise about 230 feet. Luckily, thats not going to happen all in one go! But

sea levels will rise.

Second, melting ice caps will throw the global ecosystem out of balance. The ice caps are fresh

water, and when they melt they will desalinate the ocean, or in plain English - make it less salty.

The desalinization of the gulf current will "screw up" ocean currents, which regulate

temperatures. The stream shutdown or irregularity would cool the area around north-east

America and Western Europe. Luckily, that will slow some of the other effects of global

warming in that area!

Third, temperature rises and changing landscapes in the Arctic Circle will endanger several

species of animals. Only the most adaptable will survive.

Fourth, global warming could snowball with the ice caps gone. Ice caps are white, and reflect

sunlight, much of which is reflected back into space, further cooling Earth. If the ice caps melt,

the only reflector is the ocean. Darker colors absorb sunlight, further warming the Earth.

The arctic tundra is melting already, which may be causing an increase in methane levels in

the atmosphere. A mysterious spike in atmospheric methane was measured in 2007. In addition,


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the rate of carbon increase in the atmosphere is accelerating each year, which may also be related

to the thawing of arctic areas.

4. Rising Oceans

The deep ocean seafloor is often a cold, dark place, barren of life. But from time to time a large

bounty such as a whale carcass will drift down from the surface. Then sea life explodes: all

manner of worms and other invertebrates arrive in larval form to colonize the dead organic

matter and population increases dramatically for a short time. Inevitably the resource

dwindles and the population collapses.

In a similar fashion, humans now live upon the resource of dead organic matter. Weve found

our dead whale below ground, in the form of oil, gas and coal the fossil remains of plants that

lived long ago.


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Fossil energy has fueled the advent and development of the industrial age and allowed human

population to explode. The product of our industrial respiration, carbon dioxide (CO2), has

increased in the atmosphere and now threatens to spoil our nest. Humans rely heavily on fossil

fuels in this industrial age. Carbon dioxide output has accelerated with the increased use of fossil

fuels

The atmosphere does more than provide us with oxygen to breathe; it controls the heat balance

of the world. The trouble is, compared to the ocean, the atmosphere is relatively small in mass,

so human-induced changes can affect it dramatically.

Glaciers are already melting on 5 continents.

Global sea level rise is caused by two factors. One is the delivery of water to the ocean as land

ice melts, such as mountain glaciers and polar icecaps. Current evidence of global warmingincludes the widespread retreat of glaciers on 5 continents. For example:

Some animals depend on sea ice for survival, like this mother and pup ribbon seal (Histriophoca

fasciata). Sea ice is thinning at an alarming rate.

The ice cap on Mount Kilimanjaro may be gone in 20 years. About 1/3 of Kilimanjaros ice field

has disappeared in the last 12 years and 82% of it has vanished since it was first mapped in 1912.

y Sea ice in the Arctic Ocean is thinning.y Massive Antarctic ice sheets have collapsed into the sea with alarming rapidity.

The second factor is the thermal expansion of water within the oceans. As the temperature of the

waters in the oceans rises and the seas become less dense, they will spread, occupying more

surface area on the planet. Increased temperature will accelerate the rate of sea level rise.


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Since the end of the last ice age, 18,000 years ago, sea level has risen by over 120 meters.

y Geological data suggests that global average sea level may have risen at an average rate of 0.1to 0.2 mm/yr over the last 3000 years.

y However, tide gauge data indicate that the global rate of sea level rise during the 20th centurywas 1 to 2 mm/yr.

Along relatively flat coastlines, such as those of the Atlantic, or coastlines bordering fertile,

highly populated river deltas, a 1 mm rise in sea level causes a shoreline retreat of about 1.5

meters. We are already seeing evidence of shoreline retreat in the U.S.:

Coastal U.S.has seen beacherosion and dying coastal plants.

y Along the marshy Gulf Coast of Florida, the effects of sea level rise can be observed in thenumber of dead cabbage palms at the seaward edge of the salt marsh.

y Along the Atlantic Coast of the USA, erosion is narrowing beaches and washing out vacationhouses.

Land ofsome island nations is being submerged under water.(pic)

y Tuvalu comprises nine coral atolls between Australia and Hawaii. Their highest point is 5meters (15 feet) above seal level. As sea level has risen, Tuvalu has experienced lowland

flooding. Saltwater intrusion is adversely affecting drinking water and food production.

Tuvalus leaders predict that the nation will be submerged in 50 years. In March 2002, the

countrys prime minister appealed to Australia and New Zealand to provide homes for his

people if his country is washed away, but the plight of this nation is being ignored.

y Other threatened island nations include the Cook Islands and the Marshall Islands. During thelast decade, the island of Majuro (Marshall Islands) has lost up to 20 per cent of its beachfront.


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Sea Level Rise Signals Global Warming - Coasts, Ecology, Environments Threatened

Rising seas lap at coastal community walls

A major concern of global warming is sea level rise. New satellite data proposes that the sea

level is expanding much faster than previously thought.

History ofSea Level Rise

Though of concern now, the rise and fall of the sea's relative level is actually nothing new to the

planet. V. Gorniz analyzes the historical aspects of global sea level rise in his article "Earth

Surface Processes and Landform." His research indicates that the most recent geological trend in

sea level rise began sometime around 18,000 years ago. Not long after the Last Glacial

Maximum the oceans were estimated to be 130 meters lower than today. Sea level has exhibited

a steady rise ever since, gaining total altitude equal to one and a half football fields.

However, alarming recent data from new more accurate satellite technology indicates a sudden

increase in sea level rise over the past century. According to the TOPEX/Poseidon mission

launched by NASAs Jet Propulsion Laboratory, the mean sea level is rising by about 3 mm per

year-- 3 times previous measured estimates made by tide gauge data.

Global Warming and Sea Level Rise

Varied causes make up the reason for sea level rise. However, according to numerous studies

including one sponsored by the American Meteorological Society by Church et al., a process

known as thermal expansion has the greatest effect on sea level rise in recent times, and is


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theorized to have the greatest impact on future sea level rise. As water heats up due to global

warming, it expands in volume, causing the sea level to increase. Volumetric thermal expansion

will have an additional effect on sea level as glaciers, ice sheets, and ice caps melt and add water

to the ocean.

5. Changing climate

The 10 warmest years on record have been since 1983 and the 7 warmest years on record have

been since 1990. If business continues as usual, our current rate of fossil fuel consumption

indicates that the carbon dioxide content of the air will double by 2100.

y This doubling will enhance the greenhouse effect and result in a 1 to 5 degree Centigradeincrease in global temperature.

y Land areas will warm more rapidly than the global average as the temperature of oceanic areaswill be moderated by the heat capacity of water.

y Warming will also be greatest at higher latitudes, for in the past, climate change has affectedthe earths Polar Regions to the greatest extent.

y Humidity effects, included in the heat index, will exacerbate warming effects.


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6. Warming trends affecting plant distributions and animal habitats.

Increased rain variability wetter conditions: more insect pests; drier conditions: more

wildfires

Climate extremes kill plants and animals.

A Discordant Sea: Global Warming and its Effect on Marine Populations

Global warming, an increase in the earth's average atmospheric temperature that causes

corresponding changes in climate, is a growing environmental issue caused by the influx ofhuman industry and agriculture in the mid-twentieth-century to the present. As greenhouse gases

such as CO2 and methane are released into the atmosphere, a shield forms around our Earth,

trapping heat inside of our planet and therefore creating a general warming effect. One of the

most influenced territories of warming has been our oceans.

Rising air temperatures affect the physical nature of our oceans. As air temperatures rise, water

becomes less dense and separates from a nutrient-filled cold layer below. This is the basis for a

chain effect that impacts all marine life who counts on these nutrients for survival.There are two

general physical effects of ocean warming on marine populations that are crucial to consider:

A. Changes in natural habitats and food supplyB. Changing ocean chemistry/acidification


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A. Changes in Natural Habitats and Food Supply

I) Photosynthesis

Phytoplankton, one-celled plants that live at the ocean surface and algae use photosynthesis for

nutrient fulfillment. Photosynthesis is a process that removes carbon dioxide from the

atmosphere and converts it into organic carbon and oxygen that feeds almost every ecosystem.

According to a recent NASA study, phytoplankton is more likely to thrive in cooler oceans.

Similarly, algae, a plant that produces food for other marine life through photosynthesis, is

vanishing due to ocean warming. Since oceans are warmer, nutrients are blocked from traveling

upward to these suppliers that are limited to a small surface layer and therefore cannot

supplement marine life with necessary organic carbon and oxygen.

II) Yearly Growth Cycles

Various plants and animals in our oceans need both a temperature and light balance in order to

thrive. Temperature-driven creatures, such as Phytoplankton, have started their yearly growth

cycle earlier in the season due to warming oceans. Light-driven creatures start their yearly

growth cycle around the same time. Since Phytoplankton is thriving in earlier seasons, the entire

food chain is affected. Animals that once traveled to the surface for food are now finding an area

void of nutrients and light-driven creatures are starting their growth cycles at different times.

This creates a non-synchronous natural environment.

III) Migration

The warming of oceans may also lead to migration of organisms along the east and west coasts.

Heat-tolerant species, such as shrimp, will expand northward, while heat-intolerant species, such

as clams and flounder, will retreat northward. This migration will lead to a new mix of organisms

in an entirely new environment, ultimately causing changes in predatory habits. If some

organisms cannot adapt to their new marine environment, they will not flourish and die off.


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Coral bleaching, the breakdown in the symbiotic relationship between coral and algae, is also

occurring with warmer ocean temperatures. Since Zooxanthellae, or algae, give coral its

particular coloration, increased CO2 in our oceans causes coral stress and a release of this algae.

This leads to a lighter appearance. When this relationship that is so important for our ecosystem

to survive vanishes, corals begin to weaken. Consequently, food and habitats for a great number

of marine lives are also destroyed.

IV) Holocene Climatic Optimum

This drastic climate change and its effect on surrounding wildlife is not new to us. The Holocene

Climatic Optimum, a general warming period displayed in our fossil record from 9,000 to 5,000

B.P., proves that climate change can directly impact nature's inhabitants. In 10,500 B.P., younger

dryas, a plant that was once spread throughout the world in various cold climates, became near

extinct due to this warming period. Towards the end of the warming period, this plant that so

much of nature had depended on was only to be found in the few areas that remained cold. Just

as younger dryas became scarce in the past, Phytoplankton, coral reefs, and the marine life that

depend on them are becoming scarce in the present. Our environment is continuing on a circular

path that may soon lead to chaos within a once naturally balanced environment.

Future Outlook and Human Effects

The warming of our oceans and its effect on marine life has a direct impact on us. As coral reefs

die, we will lose an entire ecological habitat of fish. According to the World Wildlife Fund, a

small increase of two degrees Celsius would destroy almost all existing coral reefs. Additionally,


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ocean circulation changes due to warming would have disastrous impacts on marine

fisheries.This drastic impact is often hard to imagine. It can only be related to a similar historical

event. Fifty-five million years ago, ocean acidification led to a mass extinction of ocean

creatures. According to the fossil records, it took more than 100,000 years for the oceans to

recover. Eliminating the use of greenhouse gases and protecting our oceans will prevent this

from reoccurring.

7. Rising Ocean Temperatures

From 1961 to 2003, the global ocean temperature has risen by 0.10 C from the surface to a

depth of 700 m. The temperature of the Antarctic Southern Ocean rose by 0.17 C (0.31 F)

between the 1950s and the 1980s, nearly twice the rate for the world's oceans as a whole. As well

as having effects on ecosystems (e.g. by melting sea ice, affecting algae that grow on its

underside), warming reduces the ocean's ability to absorb CO2).

NOAA scientists have confirmed that ocean temperatures have risen in the past few decades. In

the December 2006 article Warming of the World Ocean on the NOAA 200th Celebration site,

the organization explains how the worlds oceans have warmed by 0.06 degrees Fahrenheit from

1955 to 1998. The article explains how this may sound like a small amount but when viewed in

terms of energy this rise in temperature is equivalent to detonating 100 million Hiroshima sized

atom bombs. Releasing this energy would warm the bottom 6.2 miles of atmosphere by 40

degrees Fahrenheit. Fortunately the ocean is excellent at storing heat.

8. Changes in Ocean Ecosystems

Rising temperatures have a profound impact on marine life and not just for polar bears. The

NOAA Climate Change article explains how marine creatures are adapted for certain

temperatures and as temperatures change species will migrate to the temperatures they are suited

for. Those that cant migrate fast enough, for example clams, could die out. The September 2,

2009 Associated Press article Change is seen in Atlantic from climate, fishing says that new

population distributions have already been noticed off the United States East Coast due to

climate change and human fishing practices.


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How Deforestation Affects the Ocean

Its important to remember that the worlds many ecosystems are interconnected and what

happens in one area can affect the lives of those living hundreds of miles away. One example of

this interconnectivity is how deforestation affects the ocean. Cutting down swaths of forests

certainly has an impact on the ocean, marine life, and people living on the coasts.

Ocean Problems Often Start with Runoff

Cutting down trees often leads to more runoff meaning more water flowing from the land into

the ocean. Having trees helps reduce runoff because the trees soak up rain and the tree roots help

soil stay in place. Without forests, rainwater carries soil off into rivers which eventually flow

into the oceans. This can lead to siltation and eutrophication.

Siltation refers to the addition of silt (dirt basically) into the ocean. Dirt that flows into the ocean

can end up settling on delicate coral reefs; and if theres too much, the dirt can suffocate and kill

the corals.

Eutrophication refers to the addition of nutrients in the water. Runoff carries important nutrients

that plants need to grow, and runoff into the ocean can lead to algae blooms. These blooms can

compete with coral growth inhibiting the biodiversity of coral reefs.

Its also important to keep in mind that 80% of marine pollution comes from land-based

activities including fertilizer runoff and storm-water runoff. In agricultural areas and in cities

runoff may include pollutants such as fertilizers, toxic substances, and litter. Allowing this dirty


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water into our oceans can lead to sick beach goers and beaches are sometimes closed down to

protect swimmers.

Deforestation and Ocean Acidification

Forests help counteract the large amounts of carbon dioxide that humans pump into the

atmosphere each year trees take in carbon dioxide and emit oxygen. Deforestation however

means more of that carbon dioxide remains in the atmosphere causing problems such as ocean

acidification. Trees are not the only carbon sink around the ocean also takes in a large amount

of our carbon emissions. Unfortunately this can lead to ocean acidification. The increased carbon

dioxide affects the chemistry of the ocean which in turn affects marine life. Due to ocean

acidification creatures that rely on calcium carbonate to create their skeletons, are finding it

harder to live. Such creatures include corals, mollusks, and echinoderms.

Deforestation and Sea Level

Deforestation contributes to climate change and a warming planet leads to rising sea levels.

According to The Nature Conservancy on their webpage Saving Forest to Fight Climate

Change, deforestation and land use changes contribute to 20-25% of the carbon emissions

causing climate change. Warming temperatures cause glaciers and ice caps to melt and sea waterto expand leading to rising sea levels.

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