GLOBAL_WARMING_PRESENTATION.pptx

GLOBAL WARMING
PRESENTED BY:
Solomon T. Omitogun
(Class presentation as part of Water Resourses & Management
course, MSc Engineering Geology/Hydrogeology option.
2018/2019 University of Lagos, Akoka, Lagos Nigeria )

Outline
 Introduction
 What is global warming?
 Causes
 Effects
 Mitigating measures
 Conclusion

Introduction
 The Earth is the only known
planet habitable to living things.
 This is due to the relatively
‘conducive’ temperature range
caused by ‘the greenhouse
effect’.
 But this mechanism have been
tampered with by human
activities over the years
 This results to global warming
which have had some adverse
impacts on human lives; which
can be remediated

What is Global Warming
 To understand Global
Warming better, we
should know what the
green house effect is.
 The greenhouse effect is
how heat is retained
by the atmosphere due
to greenhouse
gases(such
as H2O, CO2,CH4,N2O,
and O3
 These gases are very
important in regulating
the Earth's temperature.

What is Global Warming?
 Global warming is the
slow increase in the average
temperature of the earth’s
atmosphere
 An increased amount of the
energy (heat) striking the
earth from the sun is being
trapped in the atmosphere
and not radiated out into
space.
 As the amount of greenhouse
gases in the atmosphere
increases, the planet
becomes warmer and warmer
on average.

 The atmosphere is a
500 km thick layer,
composed of a mixture
of gases.
 The atmosphere is
comprised of layers
based on temperature.
These are
-troposphere,
-stratosphere
-mesosphere and
- thermosphere.
 A further region at
about 500 km above
the Earth's surface is
called the exosphere.

 Solar radiation is
emitted as visible
light, UV radiation
IR radiation
 Green house
gases responsible
for global warming
are within the
troposphere and
the upper layer of
the stratosphere

Causes of Global Warming
 Human influence has
been the main cause of
global warming since the
mid-20th century.
 The concentrations of
carbon dioxide, methane
and nitrous oxide have
all increased rapidly
since 1750.
 The increase in CO2
concentration is primarily
due to burning of fossil
fuel and deforestation,
while increases in CH4
and N2O concentration
are due to agriculture.

Global Warming are generally as a
result of human activities over the
years; mostly because of:
 Fossil fuels
 Deforestation
 Intensive farming
 Waste disposal
 Oil and natural gas supply chain

 Global warming is caused by GHGs
emitted by humans such as:
 Carbon dioxide(CO2)
 Methane (CH4 )
 Nitrous oxide(N2O)
 Chlorofluorocarbons (CFCs)
 Ozone (O3)
 Water Vapour (H2O)

Carbon dioxide(CO2)
 Excess CO2 comes mainly
from burning fossil fuels —
coal, oil and natural gas
 Deforestation is another
cause of more CO2 in the
atmosphere
 Though CO2 is not the
most powerful GHG, it is
the largest contributor to
climate change because it
is so common.

Methane (CH4 )
 Methane is a strong greenhouse gas with a global
warming potential (GWP) 104 times greater than
CO2 in a 20-year time frame
 Human activities that cause the emission of
methane gas are waste disposal, waste water
treatment, biomass burning, oil and natural gas
supply chain

Nitrous oxide(N2O)
 Natural production of nitrous oxide is
from microbial activity in soils and in the
ocean
 After nitrous oxide production by the
microbes the gas goes to the
atmosphere.
 Human production of nitrous oxide is
primarily due to combustion of fossil
fuels, biomass burning, industrial
production of nitric acid, and application
of fertilizers to agricultural crops.

Chlorofluorocarbons (CFCs)
 CFCs are a group of man-made compounds containing chlorine,
fluorine and carbon.
 The production of CFCs began in the 1930s for the purpose of
refrigeration.
 Since then they have been extensively utilised as propellants in
aerosols, as blowing agents in foam manufacture and in air
conditioning. There are no removal processes or sinks for CFCs in
the lowest part of the atmosphere called the troposphere.

Ozone (O3)
 Ozone is a molecule that is made up of three oxygen
atoms linked together.
 Because of its distinct chemical properties, it serves a
dual purpose in the atmosphere- a protective layer in
the lower stratrosphere and a GHG in the troposphere
 Ozone is formed when heat and sunlight cause
chemical reactions between oxides of nitrogen (NOX )
and Volatile Organic Compounds (VOC), which are
also known as Hydrocarbons.
 This reaction can occur both near the ground and high
in the atmosphere.
 It is also mainly formed by a chemical reaction at the
lower layer of the stratosphere through the UV
radiation from the sun

Water Vapour (H2O)
 The amount of water vapor in
the atmosphere exists in direct relation to
the temperature.
 More water evaporates and becomes
vapor at increasing temperature, and
vice versa. So when something else
causes a temperature increase (such as
extra CO2 from fossil fuels), more water
evaporates.
 Then, since water vapor is
a greenhouse gas, this additional water
vapor causes the temperature to go up
even further

Effects of Global Warming
On biodiversity
 The increase of temperatures and the
climate upheavals disturb the
ecosystems, modify the conditions
and cycles of plant reproduction
 The scarcity of resources and climate
change are changing life habits and
migratory cycles of animals

On Seawater
 Ice are melting massively at the poles,
increasing the sea level at a rate never
known before.
 In a century, the increase reaches 18 cm
(including 6 cm in the last 20 years).
 It also leads to acidification of seawater,
the large amount of CO2 captured by the
oceans makes them more acidic,
arousing serious questions about the
adaptability of seashells or coral reefs.

On humans
 The scarcity of resources like food and
energy gives rise to new conflicts.
 Rising sea levels and floods are
causing population migration.
 Many are rendered homeless and
becoming refugees due to flooding

On the weather
 We are now having more droughts
and heatwaves, more precipitations,
more natural disasters like floods,
hurricanes, storms and wildfires, frost-
free season, etc.

Mitigation Measures
Renewable energies
 The first way to prevent climate
change is to move away from fossil
fuels.
 Alternatives are renewable energies
like solar, wind, biomass and
geothermal

Mitigation Measures
Energy & water efficiency
 Reducing our consumption of energy
and water by using more efficient
devices (e.g. LED light bulbs,
innovative shower system) is less
costly and equally important

Mitigation Measures
Sustainable transportation
 Promoting public transportation
 Use of electric vehicles will definitely
help reduce CO2 emissions and thus
fight global warming.

Mitigation Measures
Sustainable infrastructure
In order to reduce the CO2 emissions
from buildings - caused by heating, air
conditioning, hot water or lighting - it is
necessary both to build new low
energy buildings, and to renovate the
existing constructions

Mitigation Measures
Sustainable agriculture & forest
management
 Encouraging better use of natural
resources
 Stopping massive deforestation
 Making agriculture greener and more
efficient

Conclusion
 Global warming have been having
adverse effects on the ecosystem
within the last century
 It is therefore important and necessary
to create awareness towards putting
mitigating measures in place
 Hence, generations to come in the
next centuries are at greater risk

GLOBAL_WARMING_PRESENTATION.pptx

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