Global warming is caused by an increase in greenhouse gases from human activities like burning fossil fuels and deforestation. This traps heat in the lower atmosphere and increases Earth's temperature. Some impacts of global warming include rising sea levels submerging coastal areas, more extreme weather events, wildfires increasing, and threats to plants and animals as temperatures rise. Global warming will have widespread health, environmental, and economic effects around the world if left unaddressed.

1. Global Warming
Lecture on
Md. Abdullah-Al-Mahbub
 Assistant Professor
 Assistant Proctor
 Director, External Affairs (Former)
 Assistant Provost (Former)
Dept. of Disaster Management
Begum Rokeya University, Rangpur
Course code: 4202
Title: Global Warming and Climate Change

3. The term “greenhouse effect” & “global warming” is not the same thing. Some
definitions of global warming are given below.
1.1 What is global warming?
1. Global
Warming
An increase in the concentration of greenhouse gases
leads to an increase in the magnitude of the
greenhouse effect called enhanced greenhouse effect
and this result is global warming. Global warming is
caused by an increase in the greenhouse effect.
Global Warming is the increase of Earth's average
surface temperature due to effect of greenhouse gases,
such as carbon dioxide emissions from burning fossil
fuels or from deforestation, which trap heat that would
otherwise escape from Earth.
Global warming is the name given to an expected
increase in the magnitude of the greenhouse effect,
whereby the surface of the Earth will amost inevitably
become hotter than it is now.

4.  volcanoes,
1. 2 Global Warming
Causes of anthropogenic GHE & GW
(A) natural causes
 change in sun’s energy output,
 water vapor and cloud

5. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
 Overpopulation
 Burning of fossil fuels (natural gas, coal and oil)
 Transportation
 Electricity generation
 Deforestation
 Paper consumption
 Synthetic fertilizer
 Mining activities

6. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
Most man-made causes of global warming result from an increase in greenhouse
gases that trap or absorb infrared radiation emitted from the planet.
As the population on earth increases, food, clothes, housing and other demands
also increase. Because, more people use more fossil fuels for heating, transportation
and manufacturing. So, as more farming occurs to fulfill the demands of millions of
new people, the level of greenhouse gases continues to increase. Besides, manure
from cattle also contributes to methane gas in the atmosphere.
1.
Overpopul
ation

7. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
Carbon dioxide is the most significant cause of global warming, and most
carbon dioxide emissions result from the burning of fossil fuels. Carbon
dioxide levels in the atmosphere increase with the burning of fossil fuel that
absorbs infrared energy emitted from the earth and preventing it from
returning to space.
2. Burning of fossil fuels (natural
gas, coal and oil)

8. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
Cars, buses, and trucks are the principal vehicles by which goods and people
are transported in most of our cities. These are run mainly on fossil fuels i.e.,
petrol, diesel, or natural gas.
3.
Transportat
ion

9. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
Electricity is the main source of power in urban areas.
All industries, factories, offices, household appliances (light, TV, computer,
etc.) run on electricity. The electricity generated mainly from thermal power
plants. These thermal power plants are run on fossil fuels (mostly coal) and
are responsible for the emission of huge amounts of greenhouse gases and
other pollutants. Coal is the largest producer of carbon dioxide emissions,
giving off nearly twice as much carbon per energy unit as natural gas.
4. Electricity
generation

10. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
Timber is used in large quantities for construction of houses, which means
that large areas of forest have to be cut down. All living plants have
capabilities of storing carbon, but as the number of plants declines, the
amount of carbon dioxide free to build up in the atmosphere increases.
Moreover, decaying plants give off stored carbon into the air during the
clearing of forests or grasslands for building purposes.
5. Deforestation

11. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
We use a huge quantity of paper in our work at schools and in offices. These
papers are made from wood. More paper means cutting down more trees,
which is also a cause of global warming and climate change. Have we ever
thought about the number of trees that we use in a day?
6. Paper
consumption

12. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
We use a huge quantity of paper in our work at schools and in offices. These
papers are made from wood. More paper means cutting down more trees,
which is also a cause of global warming and climate change. Have we ever
thought about the number of trees that we use in a day?
6. Paper
consumption

13. 1. 2 Global Warming
Causes of anthropogenic GHE & GW
(B) man-made or anthropogenic causes or Human’s contribution to global warming
A growing population has meant more and more mouths to feed. That’s why
high-yielding varieties of crops require large quantities of fertilizers; and more
synthetic fertilizer means more emissions of nitrous oxide into the
atmosphere.
So, use of fertilizer in farming is one of the leading causes of global warming.
Because, nitrogen oxides trap 300 times more heat per volume than carbon
dioxide.
7. Synthetic
fertilizer

14. (B) man-made or anthropogenic causes or Human’s contribution to global warming
Mining oil and coal allows methane, a greenhouse gas, to escape from the
earth. Any time the soil is disturbed, stored gases make their way into the
environment.
Ultimately, more greenhouse gases means more infrared radiation trapped
and held which gradually increases the temperature of the earth's surface
and the air in the lower atmosphere.
8. Mining
activities
1. 2 Global Warming Causes of anthropogenic GHE & GW

15. The effects of global warming can already be seen. The IPCC's `Third
Assessment Report’ finds that in the last 40 years, the global average sea
level has risen, ocean heat content has increased, and snow cover and ice
extent have decreased, which threatens to inundate low-lying island
nations and coastal regions throughout the world. The effects of global
warming already being felt on plants and animals worldwide such as, birds
are laying eggs earlier than usual, plants are flowering earlier and
mammals are breaking hibernation sooner.
Environmental scientists inform that if only 3% average global temperature
is increased, 40 crore tones of crop-production will be obstructed and 40
crore of population will be hunger of food. The impacts of the
anthropogenic greenhouse effect and global warming can be categorized
into worldwide general impacts and particularly impacts on Bangladesh.
1. 2 Global Warming Impacts of anthropogenic GHE & GW

16. The general impacts global warming that will happen in the future are
categorized into :
(A) health impact,
(B) environmental impact and
(C) economic impact
1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts

17. 1. Ultraviolet (UV-B) radiation causes skin cancer, cataracts and immune
suppression in both animals and humans. Thus, human beings would be
more prone to infectious disease. UV-B also damages plants including
hardwood forests, and phytoplankton (an algae is a type of
phytoplankton which is the building block of the oceanic food chain).
1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts 1. Health impact
2. The most common heat-related illness is heat exhaustion, whose
symptoms include intense thirst, heavy sweating, anxiety, dizziness,
fainting, nausea or vomiting, and headache.
3. The urban heat island also absorbs heat during the daytime and
radiates it out at night, raising nighttime minimum temperatures, which
has been linked epidemiologically with excess mortality.
4. Higher temperatures combined with extended periods of drought and
decreased soil moisture raises the risk of wildfires and the death and
damage they inflict.
5. Another health-related impact from more frequent and larger fires: the
increase in fine particulate air pollution, both in the immediate vicinity
of fires and in areas downwind.
6. Migration of diseases such as malaria, dengue to new, now warmer,

18. 1. Wildfires are increasing due to higher temperature. Again forest fires
create more global warming. Because, trees normally serve as a reserve
or “sink” of carbon, absorbing and holding carbon in place. When they
burn, instead of acting as carbon sinks, trees release their carbon to the
atmosphere, increasing the greenhouse effect and ultimately influence
global warming.
1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts 2. Environmental impact

19. 1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts
2. Significant melting of old
glaciers and ice caps are already
observed, causes loss of habitat
near the poles. Polar bears are
now thought to be greatly
endangered by the shortening
of their feeding season due to
dwindling ice packs.
3. Increase in the flow of rivers causes flooding of low lying coastal areas
and water pollution.
2. Environmental impact

20. 4. Rising sea levels submerse coastal low-lying cities and islands and also
pollute fresh groundwater supplies with salt water.
1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts 2. Environmental impact
5. More extreme weather, occurrence of more intense rainstorms,
cyclones and hurricanes will have severe impacts on the environment
and on society. Droughts and fires in some areas, flooding in other areas
will have observed. Agricultural crops will damage and animal’s
populations will extinct.
6. Bleaching of coral reefs due to warming seas and acidification due to
carbonic acid formation. About one third of coral reefs now appear to
have been severely damaged by warming seas.
7. Expansions of deserts into existing rangelands.
8. Refugee problems will increase. Not all long-term effects can be
determined.

21. Global warming also affects our economy. Warmer temperature is helpful
for growing certain types of pests which can attack and kill the plants.
Increasing temperature creates water shortage and drought problem that
also kill the food and cash crops. Moreover it can also increase forest fires,
cyclones that can cause billions of dollars of damage, raising health care
and insurance costs.
1. 2 Global Warming Impacts of anthropogenic GHE & GW
A. General Impacts 3. Economic impact

22. Bangladesh is less responsible for global warming, but will be one of the
most victim countries for her geographical location. Bangladesh is
concerned for the following impacts of global warming:
 Because of global warming, average temperature of earth and
atmosphere is rising. As a result the Himalayan and polar Ice (Glacier) is
melting. The melting water will flow onto low-lying areas and ultimately
come into ocean via river and low lying flood plain will go under water.
 Rising sea level.
 The coastal area of Bangladesh will go under the Bay of Bengal.
 Change of precipitation (rainfall pattern) and local climate conditions.
 Bangladesh will have to face critical food crises and refugee problems.
 The largest mangrove forest in the world will be destroyed.
 Total environmental balance will be destroyed.
1. 2 Global Warming Impacts of anthropogenic GHE & GW
B. Impact of Bangladesh

23. 1. 2 Global Warming Impacts of anthropogenic GHE & GW
B. Impact of Bangladesh