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Global Environmental
Problems and
Global Efforts
ByN.S.Srinidhi, Asst. Professor, Vidya Jyothi Engineering College, RR - Telangana
GREEN HOUSE EFFECT
55% contributor to Global
Warming & 500 yrs life span
18% contributor to
Global Warming
(GW) and 7-10 yrs
life span
6% contributor
and 140-190 yrs
life span
1000 yrs life span
CFC’S24% Contributor &
life span of 110 yrs
GLOBAL WARMING Presences of GHE, avg. global
temperature is 15°C.
In absences of them it would be -18°C.
Therefore GHE, contributes 33°C temperature rise.
Two Important GHG’s are Water Vapour & CO2.
BCoz of excess GHG’s, scientist worry about incraese in avg temp. more than 15°C.
Causes due to Deforestration, Anthropogenic activities like fossil fuel burning.
This leads to Sea Level Rise.
SEA LEVEL RISE
In the last century 15-20 cm rise in se level has been witnessed.
IPCC projected rise in between 18 and 59cms.
Reasons:
1)Thermal Expansion2)Melting of Ice
End of 21st Century, rise is expected to be between 0.56 and 2m.
Melting of Greenlands & West Antarctica – 6m rise.
Causes:
Flooding of Coastal areas like Bangladesh, Mumbai, Lakshadweep
Disturb Spawning grounds.
Disturb Coastal Fisheries.
Flooding agriculture lands & low land.
Increases Soil Erosion
Increases Salinity of aquifers & Estuaries.
Inundate large areas of Wetlands.
CLIMATE CHANGE1. Climate is the average weather of an area.
2. The Intergovernmental panel of Climate Change (IPCC) – 1990 & 1992 published the best available evidence about past climate change, GHE and Global Warming during the geological times.
3. Anthropogenic activities – Upset Hydrological Cycle, Results in flood and Drought, causes sea level rise, changes in agriculture productivity, famines, death of humans & livestock.
4. The global changes in temperature will not be uniform everywhere and will fluctuate in different regions.
5. Poles experience 2 to 3 times more warming than the global average, while warming in the tropics may be only 50 to 100% on an average.
Earth’s Temperature will rise in between 1.5°C to 5.5°C by 2050.
Impact on Human Environment
1. Global Temperature Increase:
2. Rise in Sea Level:Expanding of water due to
increase in temperature.
•Melting of Polar Ice Caps.
•Increase in Global Sea
Level by 0.2-1.5 metres
over the next 50-100 years.
•One meter rise will
inundate Sydney, Bangkok,
Cairo etc, Agricultural
Lands of Bangladesh, India,
China will effect rice
production.
•Lives of many people living
near these cities.
3. Effects on Human
Health:
Spread of Diseases like
Filariasis, Elephantiasis,
Malaria etc.
As the Vectors spreading
these diseases will be
increase in no. due to
stagnation of water and
high temperature to
survive(Mosquitoes, Snails
Etc).
Increase in Respiratory and
Skin Diseases due to high
temp. & Humidity.
4. Effect on
Agriculture:
•Soil Moisture will
decrease & evapo-
transpiration will
increase – affecting
wheat and maize
production.
•Increase in pest no.
due to high temp. &
Humidity.
•To cope up this pest,
heat and drought
resistant varieties to be
developed.
OZONE LAYER DEPLETION
Ozone Formation
Atmospheric Ozone measured using Dobson
Spectrophotometer and expressed in Dobson
Units(DU).
Temperate Latitudes = 350 DU
Tropics = 250 DU
Sub- Polars = 450 DU
Ozone Hole:
An undeniable problem in Antarctica
Researcher Joseph Farman had been collecting
atmospheric data at Halley Bay, Antarctica since
1957. Every year he sent a team of research
assistants to measure ozone levels and
concentrations of trace gases like CFCs.
In 1982, his ozone reading showed a dramatic dip
— around 40%. Rather than being alarmed, he was
skeptical of the data and thought it must be an
instrument malfunction.
Ozone Hole over the Anatartica
OZONE DEPLETING SUBSTANCES1. CFC’s2. Halon3. Carbon Tetrachloride(CCl4), Methyl Chloroform(CH3CCl3)4. Hydrobromofluorocarbons (HBFC’s)5. Hydrochlorofluorocarbons(HCFC’s)6. Methyl Bromide(CH3Br)7. Bromochloromethane(CH2BrCl)
Effects of Ozone Depletion1. Mutation in the DNA – Hereditary Problems.2. Skin Cancer.3. UV absorbed by lens and Cornea – Cataract.4. Melanin in skin destroyed by the UV.5. Decrease in Phytoplankton Population – Later impacting the ecosystem.6. Yield of crops like corn, rice, soyabean, cotton etc are decreased.7. Degradation of Paints, Plastics and other polymer material will result in economic loss due to UV rays.
Deforestation
Facts: Forest Cover in Total World in 1900 was 7000 Million
Hectares, but in 1975 – 2980 Million Hectares and in 2000 – 2300 Million Hectares.
Due to global efforts in 2010 it increased to 4033 Million Hectares.
In next 60 years about 90% of the tropical forests will be destroyed.
India’s Forest cover is 21.02%.(2009 Forest Report)
Major Causes of Deforestation Shifting Cultivation
Fuel Requirement
Raw Material for Industrial Use
Developmental Projects.
Growing Food Needs.
Over Grazing
Forest Fires.
Consequences
Extinction of Species due to habitat loss.
Hydrological Cycle effected thereby effecting rainfall.
Soil Erosion and loss of soil fertility.
Landslides in hilly areas.
Moe Carbon is added into the atmosphere, thereby enhancing Global Warming.
Desertification
Productive Potential of Arid & Semi-Arid lands falls by 10% or more.Moderate Desertification – 10-25% drop in productivity.Severe – 25 – 50%Very Severe – more than 50%
Consequences:Loss of VegetationGround water depletionSalinization and severe soil erosion
Causes of Desertification
Natural Phenomena – Climate Change
Anthropogenic Factors
1. Deforestation
2. Over Grazing
3. Mining and Quarrying.
Thank You