This document discusses climate change, defining it as changes in long-term weather patterns caused by both natural and human factors that increase greenhouse gases. It outlines the main greenhouse gases, their sources, and their effects on trapping heat. Deforestation is another significant cause of climate change. Evidence of climate change includes rising global temperatures, melting glaciers and rising sea levels, increased ocean acidification, and changes to rainfall patterns and extreme weather events. Preventing further climate change will require both reducing greenhouse gas emissions through mitigation efforts as well as adapting to the changes already occurring through climate adaptation strategies.

1. By: Mohd Ali(PhD Scholar),
Centre for Applied Geology
Gandhigram Rural Institute,
Tamil Nadu

2. OVERVIEW
Difference between climate and
weather.
Definition of climate change.
Causes :
Green house gases.
Deforestation.
Mechanism.
Evidences
Effects.
Preventive measures.

3. • WEATHER
• Short term
• Limited area
• Can change rapidly
• Difficult to predict
Weather is what's happening
outside our window right now
• CLIMATE
• Long term
• Wide area
• Seasonal change
• Measured over long span of time
Climate is the average of
many years of weather
observation.

4. CLIMATE CHANGE
DEFINITION

5.  When the incoming energy from the sun is
absorbed by the earth system, earth is
warmed .
 when the sun’s energy is reflected back into
space , earth cools.
 Both natural and anthropogenic factors can
cause changes in earth’s balance.

6. Causes
1. GREEN HOUSE GASES
AND CLIMATE CHANGE
The main greenhouse gases include:
 Water vapour
 Carbon dioxide(Co2)
 Methane
 Nitrous oxide
 Chlorofluorocarbons (CFCs)
GHS keep the average surface temperature of
earth around 14ºC.
Without the natural greenhouse effect, the
Earth’s average surface temperature would be
around -19°C.
 As the human activity has increased due to onset of
industrial revolution, the emission of huge amount of
Green House Gases is also increased which led to
more absorption of heat being retained in the
atmosphere thus an increase in global Temperature.

9. METHANE
The large sources of Methane
come from the decomposition
of organic matter e.g. in
landfills and in agriculture and
from the digestion of
ruminants (cows, goats etc.)
 It is a stronger GHG than CO2
because it can absorb more
heat.
However it is much less
abundant in the atmosphere.

11. Nitrous oxide
 It is considered as a very
powerful greenhouse gas which
is abundantly produced in the
agriculture sector, specifically in
the production and use of organic
fertilizers.
 It is also produced when
burning fossil fuels.

12. Chlorofluorocarbons (CFCs)
These man-made compounds
were produced for industrial use,
mainly in refrigerants and air
conditioners.
They are now regulated under
the Montreal Protocol due to
their adverse effect on the Ozone
Layer.

13. DEFORESTRATION
Deforestation is the second leading cause of global warming and produces
about 24% of global greenhouse gas emissions
Cutting down forests led to changes in the amount of sunlight reflected
from the ground back into space (the surface albedo).
High Latitudes region is largely affected due to deforestation as the albedo
of snow-covered land, previously forested, has increased. This is because
snow on trees reflects only about half of the sunlight falling on it, whereas
snow-covered open ground reflects about two-thirds. Overall, the increased
albedo over agricultural regions has had a cooling effect.

14. Tropical deforestation which changes evapotranspiration rates (the amount of water
vapour put into the atmosphere through evaporation and transpiration from trees),
desertification, which increases surface albedo, and the general effects of agriculture
on soil moisture characteristics.

15. GLOBAL WARMING AND CLIMATE
CHANGE(mechanism)

16. EVIDENCE OF CLIMATE CHANGE
(EFFECTS)

17. HIGH TEMPERATURE
Green House gases release by power plants, automobiles, deforestation and other sources
are heating up the planet.
Increased temperatures are to blame for an increase in heat-related deaths and illness,
rising seas, increased storm intensity, and many of the other dangerous consequences of
climate change.
average surface temperatures could increase by 3 to 10 degrees Fahrenheit by the end of
the century.
MELTING GLACIERS/RISING SEAS LEVEL
As the Earth heats up, sea levels rise up because warmer water takes up more area than
colder water, a process known as thermal expansion.
 Melting glaciers compound the problem by dumping even more fresh water into the
oceans.
Rising seas threaten the populated low-lying areas, islands and dense coastal
populations, erode shorelines, damage property and destroy ecosystems such as
mangroves and wetlands that protect coasts against storms.

18. OCEAN ACIDIFICATION
The increased concentration of carbon dioxide (CO2) in the
atmosphere has increased the absorption of CO2 in the ocean, which
reduces the pH and makes the oceans more acidic. A more acidic
ocean would adversely affect the health of many marine species,
including plankton, molluscs, and other shellfish. In particular, corals
can be very sensitive to rising acidity, as it is difficult for them to
create and maintain the skeletal structures needed for their support and
protection.
INCREASED RISK OF DROUGHT, FIRE AND FLOODS
Higher temperatures increase the amount of moisture that evaporates
from land and water, leading to drought in many areas. Lands affected
by drought are more vulnerable to flooding once rain falls.
Hot temperatures and dry conditions also increase the likelihood of
forest fires.

19. RAINFALL PATTERNS
Rainfall patterns are changing around the world. Research shows the
global water cycle is intensifying with a warming climate, which
means wet areas are likely to get wetter and dry regions are likely to
be drier in response to climate change.
OTHERS EFFECTS
 Wildlife/Ecosystem at Risk
 Changing Landscapes
 Intensified Storms and Increased Storm Damages
 Illness and Disease
 Economic Losses
 Agriculture Productivity/Food Security

20. Dealing with Global Climate Change-
Relationship Between Mitigation and
Adaptation