dr. muhammad razzaq malik. global environment environment of our planet is changing in ways that...

Dr. Muhammad Razzaq Malik


GLOBAL ENVIRONMENT

• Environment of our planet is changing in ways that could have serious consequences for human health.

• Planet provides us– Food– Air– Water– And every thing that sustains life


EARTH

• Planet presents us:

–Earth quacks

–Drought

–Climate changes

–Destroy our life

–Disrupt society


ENVIRONMENT

• COMMUNICABLE DISEASES

• CHRONIC DISEASES

• TECHNOLOGICAL ADVANCES

• RAPID POPULATION GROWTH


WATER SHORTAGES

• Rapid population growth• Ground water pumping• Diversion of water from lakes and rivers-irrigation• Shortage of water---shortage of foods

– Long distance transfers– Conservation of water– Recycling of some water

• WHO=35% of world’s people- adequate water supply

less than 1 % of the world’s fresh water on earth is readily accessible for direct human use.


WORLD POPULATIONPOPULATION GROWTH (WORLD)

0.51

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

10

y-1600 y-1804 y-1927 y-1960 y-1974 y-1987 y-1999 y-2013 y-2026 y-2045

YEAR

PO

PU

LA

TIO

N IN

BIL

LIO

NS


Protection of Water supply

• Take showers, not bath• Do not let water run, when it is not being used

actively• Install sink faucet aerators & water efficient showers• Use less water in toilets in each flush• Fix any leaky faucets in your house• Use organic rather chemical fertilizer• Do not pour toxic materials in the drain• Plant your lawn with plants requiring less water• Avoid watering lawn during hottest part of the day.


EARTH

• BIOSPHERE– Troposphere 6-10 Km in which

temperature falls with increasing height– Stratosphere 11-50 Km– OZONE layer 12-24 Km


GREEN HOUSE EFFECT

• To stabilize earth’s temperature• These gases permit the passage of visible and

UV radiations from the sun• These warm the earth’s surface• Block the escape back into space. • Green house effect maintains the biosphere

within the temperature range that sustains life.• The surface temp. falls if solar radiation is

blocked by dust in the stratosphere.


GREEN HOUSE EFFECT

• Rise in conc. Of green house gases• Rise in temperature of biosphere• GASES:

– Carbon dioxide, oxides of nitrogen, methane, chlorofluorocabons (CFCs), ozone, others

• All are due to human activity– Internal combustion– Motor vehicles– Electric power generators– Industrial processes– Respiration by increasing population– Agricultural and other sources like rotting of vegetations


SOURCES OF GREEN HOUSE GASES


THE PREENHOUSE EFFECT


GREEN HOUSE EFFECT

• Conc. of these gases has increased in the troposphere sharply

• Accumulation of green house gases are beginning to raise global temp.

• Estimated 0.5 to 1 Cº from 1980-1990 more rapidly in the last 10 years.

• Estimated 3 to 4 Cº in next 50 to 100 years.


SMOKING


HAZARDS OF SMOKING


CIGAR


GLOBAL WARMING

• Local, regional & global ecosystems• Sea levels and ocean currents due to smelting of

glaciers • Prevailing winds -------alter distribution of rain fall• Fresh water supplies• Agriculture• Forests• Fisheries• Industries• Transport• Urban planning• Demographic and human health.


GLOBAL WARMING

• Six out of ten hottest summers since record keeping occurred in 1980s

• 1988 summer was unusually very hot

–Bad season for grain crops

–Drastic reduction in world grain reserves.


GLOBAL WARMING

1. Grass lands and prairies get hotter, they dry out and become even hotter,

• Self correcting effects of vegetation on microclimates is lost

• Decline in soil moisture and impaired grain production2. Altered habitat of insects, pests---disease3. Forests are disappearing because of human depredation

like to increase agricultural land and to cut to gather for hardwood trees.

4. Increase in carbon dioxide due to decrease in vegetation that can lead to loss of many species of animals & plants


GLOBAL WARMING

5. Global warming could thaw (melt) permafrost releasing long frozen vegetation to arctic ponds and bogs. This will lead to emission of methane - a green house gas.

6. Violent weather disturbances due to oceanic upwelling and thermal air currents

e. g. hurricanes, cyclones etc


GLOBAL WARMING

• Rise in sea level due to thermal expansion of sea water mass and to melting of ice caps. In a worst case scenario, entire Antarctic ice shelf would break and melt, causing a sea level rise to 5-7 meters.

• 1-1.5 M rise is predicted in next 50-100 years. This will cause submerge of coastal areas

7. Monsoon floods due to deforestation on Himalaya can lead to deluge of run off rains in Bangladesh.


GLOBAL WARMING

8. Coastal wetlands due to flooding –depletion of fish stock

- Drowning of coastal communities

- Ecological disasters like spilling of oil increases the danger

- Food shortages

9. Fresh water supplies are threatened by salination to coastal estuaries


GLOBAL WARMING

• 10. Changes in the distribution of vegetation. Areas now devoted to grains crops will become drier, desertified, top soil is lost in dust storms.

• 11. distribution of insect vectors of diseases


HEAT ISLANDS

• This makes cities warmer than surrounding rural areas will lead to longer and more severe heat waves than we are accustomed now.

• This will strain utilities and other essential services.

• Heat waves increase the demand for air conditioning, extra consumption of fossil fuels will add burden of green house gases.


OZONE DEPLETION

• Stratospheric ozone is located at an altitude of 12 to 24 km.

• This layer protects against harmful biological effects of UV radiations.

• It causes DNA damage proportional to the amount of exposure.


OZONE LEVEL


RADIATIONAL HAZARDS

dr. muhammad razzaq malik. global environment environment of our planet is changing in ways that...

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