3. IT GIVES US IMMENSE PLEASURE TO BE ASSOCIATED WITH THE
GROUP DISSCUTION ON GLOBAL WARMING , ACID RAIN , AIR
POLLUTION. WITH THEIR CONSEQUENCES . THEIS GROUP
DISSCUTION WAS A JOYOUS LEARNING PROCESS AND HELPED
US IN LEARNING OUR THEORITICAL AND PRACTICAL
KNOWLEDGE THE PROJECT HAS BEEN COMPLETED UNDER THE
SUPERVISION OF Ms. KABITA MAM WE ARE HIGHLY THANKFUL
TO HER FOR HER GUIDANCE DURING THE COURSE OF THIS
WALK.WE ALSO EXPRESS OUR PRINCIPAL SIR V.S. RAI, VICE
PRINCIPAL MAM DR. REENA RAJPUT, HEAD MISTRESS MAM
AMRITA MOTWANI AND MANAGEMENT MEMBERS OF OUR
SCHOOL FOR THEIR MORAL SUPPORT. LAST BUT NOT THE
LEAST WE ARE EXTREMELY GRATEFUL TO OUR PARENTS AND
FRIENDS FOR THEIR VALUABLE SUGGESTIONS TO COMPLETE
THIS GROUP DISSCUTION
ACKNOWLEDAGEMENT
4.
5.
6. Climate model projections summarized in the latest IPCC
report indicate that the global surface temperature is
likely to rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during
the 21st century.[2] The uncertainty in this estimate
arises from the use of models with differing sensitivity to
greenhouse gas concentrations and the use of differing
estimates of future greenhouse gas emissions. An
increase in global temperature will cause sea levels to
rise and will change the amount and pattern of
precipitation, probably including expansion of
subtropical deserts.[4] Warming is expected to be
strongest in the Arctic and would be associated with
continuing retreat of glaciers, permafrost and sea ice.
Other likely effects include changes in the frequency and
intensity of extreme weather events, species extinctions,
and changes in agricultural yields. Warming and related
Global warming
Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-
20th century and its projected continuation. According to the 2007 Fourth Assessment Report by the
Intergovernmental Panel on Climate Change (IPCC), global surface temperature increased 0.74 ± 0.18 °C
(1.33 ± 0.32 °F) during the 20th century.[2][A] Most of the observed temperature increase since the middle of the
20th century was caused by increasing concentrations of greenhouse gases, which results from human activity
such as the burning of fossil fuel and deforestation.[3] Global dimming, a result of increasing concentrations of
atmospheric aerosols that block sunlight from reaching the surface, has partially countered the effects of
greenhouse gas induced warming.
changes will vary from region to region around the globe, though the nature of these regional variations is
uncertain.[5] Another major[6][7] worldwide concomitant of global warming, and one which is presently happening
as well as being predicted to continue, is ocean acidification, which is likewise a result of contemporary increases
in atmospheric carbon dioxide.
13. Each year from 1998 through 2007 ranks
among the top 25 warmest years on record for
the United States, according to the National
Oceanic and Atmospheric Administration.
Scientists say that the earth could warm by an
additional 7.2 degrees Fahrenheit during the
21st century if we fail to reduce emissions from
burning fossil fuels, such as coal and oil. This
rise in average temperature will have far-
reaching effects on the earth's climate patterns
and on all living things. Many of these changes
have already begun.
14. Hot, dry weather led to a record-setting 2006 wildland fire
season with close to 100,000 fires reported and nearly 10
million acres burned, 125 percent above the decade's
average.
In July 2006, severe heat waves in North America contributed to
the deaths of at least 225 people.
In 2005, scientists reported that some polar bears are
drowning because they have to swim longer distances to
reach ice floes - they're now being considered for listing under
the Endangered Species Act.
At the current rate of retreat, all of the glaciers in Glacier
National Park will be gone by 2070.
15.
16. Acid rain is a rain or any other form of precipitation that is unusually acidic, i.e.
elevated levels of hydrogen ions (low pH). It can have harmful effects on plants,
aquatic animals, and infrastructure through the process of wet deposition. Acid rain is
caused by emissions of compounds of ammonium, carbon, nitrogen, and sulfur which
react with the water molecules in the atmosphere to produce acids. Governments
have made efforts since the 1970s to reduce the production of sulfur dioxide into the
atmosphere with positive results. However, it can also be caused naturally by the
splitting of nitrogen compounds by the energy produced by lightning strikes, or the
release of sulfur dioxide into the atmosphere by volcano eruptions
Definition
"Acid rain" is a popular term referring to the deposition of wet (rain, snow, sleet, fog,
cloudwater, and dew) and dry (acidifying particles and gases) acidic components. A
more accurate term is “acid deposition”. Distilled water, once carbon dioxide is
removed, has a neutral pH of 7. Liquids with a pH less than 7 are acidic, and those
with a pH greater than 7 are Alkaline. “Clean” or unpolluted rain has a slightly acidic
pH of about 5.2, because carbon dioxide and water in the air react together to form
carbonic acid, but unpolluted rain also contains other chemicals.[1]
H2O (l) + CO2 (g) → H2CO3 (aq)
Carbonic acid then can ionize in water forming low concentrations of hydronium and
carbonate ions:
2 H2O (l) + H2CO3 (aq) CO32− (aq) + 2 H3O+ (aq)
Acid deposition as an environmental issue would include additional acids to H2CO3
Acid rain
17.
18.
19.
20.
21.
22.
23.
24.
25.
26. Acidification of rain-water is identified as one of the most serious environmental
problems of transboundary nature. Acid rain is mainly a mixture of sulphuric and
nitric acids depending upon the relative quantities of oxides of sulphur and
nitrogen emissions. Due to the interaction of these acids with other constituents
of the atmosphere, protons are released causing increase in the soil acidity
Lowering of soil pH mobilizes and leaches away nutrient cations and increases
availability of toxic heavy metals. Such changes in the soil chemical
characteristics reduce the soil fertility which ultimately causes the negative
impact on growth and productivity of forest trees and crop plants. Acidification of
water bodies causes large scale negative impact on aquatic organisms including
fishes. Acidification has some indirect effects on human health also. Acid rain
affects each and every components of ecosystem. Acid rain also damages man-
made materials and structures. By reducing the emission of the precursors of
acid rain and to some extent by liming, the problem of acidification of terrestrial
and aquatic ecosystem has been reduced during last two decades
27.
28. Air pollution is the introduction of chemicals, particulate matter, or biological materials
that cause harm or discomfort to humans or other living organisms, or damages the
natural environment into the atmosphere.
The atmosphere is a complex dynamic natural gaseous system that is essential to
support life on planet Earth. Stratospheric ozone depletion due to air pollution has long
been recognized as a threat to human health as well as to the Earth's ecosystems.
Indoor air pollution and urban air quality are listed as two of the world's worst pollution
problems in the 2008 Blacksmith Institute World's Worst Polluted Places report.[1]
An air pollutant is known as a substance in the air that can cause harm to humans and
the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases.
In addition, they may be natural or man-made.[2]
Pollutants can be classified as either primary or secondary. Usually, primary pollutants
are substances directly emitted from a process, such as ash from a volcanic eruption,
the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from
factories.
Secondary pollutants are not emitted directly. Rather, they form in the air when primary
pollutants react or interact. An important example of a secondary pollutant is ground
level ozone — one of the many secondary pollutants that make up photochemical smog.
Air pollution
29.
30.
31.
32.
33.
34. Carbon dioxide emissions
Most Polluted World Cities by PM[29]
Particulate
matter,
μg/m³ (2004)
City
169 Cairo, Egypt
150 Delhi, India
128 Kolkata, India (Calcutta)
125 Tianjin, China
123 Chongqing, China
109 Kanpur, India
109 Lucknow, India
104 Jakarta, Indonesia
101 Shenyang, China
Total CO2
emissions
35. Countries with the highest CO2
emissions
Country
Carbon dioxide emissions per
year (106
Tons) (2006)
Percentage of global total
China 6,103 21.5%
United States 5,752 20.2%
Russia 1,564 5.5%
India 1,510 5.3%
Japan 1293 4.6%
Germany 805 2.8%
United Kingdom 568 2.0%
Canada 544 1.9%
South Korea 475 1.7%
Italy 474 1.7%
36. Countries with the highest per capita CO2
emissions
Country
Carbon dioxide emissions per year
(Tons per person) (2006)
Qatar 56.2
United Arab Emirates 32.8
Kuwait 31.2
Bahrain 28.8
Trinidad and Tobago 25.3
Luxembourg 24.5
Netherlands Antilles 22.8
Aruba 22.3
United States 19
Australia 18.1
37. Air pollution can have disastrous consequences on agriculture close to pollutant
sources. Research at the Stockholm Environment Institute at York (SEI-Y) is assessing
the link between air pollution, agricultural production and subsequent food security. Dr
Lisa Emberson of SEI-Y, who is co-editor of a recently published book entitled Air
Pollution Impacts on Crops and Forests, says that studies conducted in the Hunan
Province of China found that sulphur dioxide originating from coal-burning power
stations resulted in 100% yield losses for sensitive crop species; similarly in India,
crops grown in the vicinity of power plants recorded yield reductions of up to 50%.
However, it is the regional pollutant ozone that is perceived as the biggest threat
to future agricultural productivity since levels reach high concentrations over remoter
rural agricultural areas. Ozone is a secondary pollutant that is formed by the effect of
sunlight on other pollutants, and filtration studies conducted in Pakistan illustrate the
dramatic growth reductions caused by ambient ozone levels. Such impacts on
agricultural productivity can have serious implications where problems of food
scarcity exist; studies in India have found that vulnerable sectors of society such as
the poor and malnourished as well as those depending on sustainable agriculture for
their livelihoods are more severely affected. The book has collated key studies in an
attempt to assess the consequences of current and future global air pollutant
concentrations on agricultural systems. The Asian region was identified as that facing
the most serious risks to agricultural productivity both now and in the future