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LEARNING MODULE IN TRENDS, NETWORKS, AND CRITICAL THINKING

GRADE 12 HUMSS
FOURTH QUARTER, WEEK 2
MODULE NO. 2
CLIMATE CHANGE: ITS NATURE AND CAUSES
TITLE

LEARNING COMPETENCY

Explain the effects of consumption and production patterns on climate change (HUMSS_MCT12-Ih-i-2)

OVERVIEW / TO DO LISTS
LEARNER – In this module, you will be able to examine the primary causes of climate change. For you to be
able to do the activity correctly, read the instruction on every activity. Ask the guidance of your parent in
doing the activity if there are things you can’t understand on the module.
FACILITATOR – Please facilitate your child upon answering or completing this module. Let them do
the task independently.
INTRODUCTION TO THE LESSON
Climate change is an inevitable natural phenomenon that we are all experiencing at the present time.
Droughts and severe typhoons are just few of the manifestations of climate change. But it is important to ask,
what is climate change? What are its causes? How did it happen? This lesson will help you answer these
questions.

LEARNING OBJECTIVES
 Understand the nature of climate change
 Explain how the effects of human consumption and production patterns contribute to the climate
change problem
 Examine the primary causes of climate change
WHAT I KNOW
Instructions: What words can you associate when you hear the word “climate change?” Write your answers
using the concept map below.

Climate Change

LESSON PROPER
REVIEW
Globalization is the keyword for the rise of global networks. But what is globalization? How does
globalization relate to global networks? Globalization is rooted from the word global which means that actions
occur "across political and cultural boundaries," which creates intensive as well as spatially extensive
interconnections between a range of institutions, and actors; and develops " transnational processes,
institutions, and ways of interpreting the world as a single space" (Holton, 2008, 6). Globalization is the
process in which the economies of different countries around the world become increasingly assimilated over
time. This process of interaction and integration among the people, companies, and governments happens as
technological advancements accelerate.
WHAT I NEED TO KNOW
THE NATURE OF CLIMATE CHANGE
Climate refers to average weather in a particular place. It includes precipitation temperature, humidity, wind,
and seasons. Climate patterns play an important part in the formation of natural ecosystems. Human economies and
cultures also depend on climate. However, in recent times, our climate has changed drastically with disturbing impacts.
It is observed that the change in our climate is progressing faster in the last 2,000 years. Since 1900, the global average
temperature has risen by 0.7°C while the northern hemisphere is noticeably warmer than at any point during
the past one thousand years. These small changes in the Earth's average temperature can lead to great and
potentially dangerous changes in climate and weather patterns. Many places throughout the world have
experienced changes in the amount of rainfall which resulted to more floods, intense rains or droughts, and
severe heat waves. The oceans and glaciers have also experienced some significant changes. The oceans
become warmer and more acidic, ice caps started to melt; and sea levels began to rise. These changes in our
environment in recent times are big challenges to human society. These phenomena is referred to as climate
change. Climate change refers to a significant change in the climate conditions and measures that usually lasts
for an extended period of time. It involves major changes in temperature, precipitation, or wind patterns that
can occur over a particular length of time. Global warming, on the other hand, is caused by an ongoing rise in
global average temperature near Earth's surface. It is due to an increasing concentrations of greenhouse gases
in the atmosphere. Global warming causes changes in climate patterns. It represents an aspect of climate
change.
CAUSES OF CLIMATE CHANGE
Humans can live and survive on earth because of the sufficient heat that we receive from the Sun.
Some of the solar radiation bounces back into space but a small portion of it is trapped by the delicate balance
of gases that make up our atmosphere. Without this coating of insulation, the Earth would become a frozen
rock. Carbon dioxide or CO, is considered as the most important gas in the Earth's layer of insulation. Carbon
dioxide is released into the atmosphere through different human activities such as fossil fuel (e.g., coal, oil and
gas) burning and cutting down trees. Because of this, our atmosphere contains about 42% more carbon
dioxide than during the industrial era. The increasing release of carbon dioxide and other greenhouse gases,
namely water vapor, and smaller amounts of carbon dioxide, methane, and nitrous oxide, made the Earth's
atmosphere into a thick, heat-trapping blanket. Because of the disruption of the atmospheric balance that
maintains the stability of the Earth's climate, our planet is now experiencing the effects of climate changes.
Human changes in land use and land cover have altered the Earth's reflectivity or the ability of the Earth to
absorb or reflect the amount of sunlight. Deforestation or the destruction of forest: desertification or the
process of land degradation in arid or dry, semiarid and subhumid regions of the world, and urbanization or
the movement of people to the cities contributes to changes in climate.

Climate scientists believe that the main cause of the current global warming trend is the human
expansion of the greenhouse effect. What is greenhouse effect?
When sunlight reaches the surface of the Earth, it can either reflect the light back into the space or it
can be absorbed by the Earth. Once it is absorbed, the Earth releases some of the energy back into the
atmosphere as heat or infrared radiation Greenhouse gases or GHGs include water vapor (HO), carbon dioxide
(CO), and methane (CH) and they absorb energy which slows or prohibits the loss of heat to space. In this way,
greenhouse gases serve like a blanket that makes the Earth warmer than it would otherwise be. This process is
commonly known as the "greenhouse effect.

Gases that contribute to the greenhouse effect are the following:

1. Water vapor (H20) - The water vapor is considered as the most abundant greenhouse gas. It serves as a
feedback to the climate. It usually increases as the Earth's atmosphere warms.
2. Carbon dioxide (CO2) - Carbon dioxide is the principal greenhouse gas that contributes to climate change. It is
released through natural processes such as respiration, volcanic eruptions, and through human activities such as
deforestation, land use changes, and fossil fuel burning Humans have increased atmospheric carbon dioxide
concentration by one third since the beginning of the Industrial Revolution Currently, human activities release over 30
billion tons of CO, into the atmosphere annually. This is the most important cause of climate change.
3. Methane (CH4) - Methane is a hydrocarbon gas produced by natural sources and human activities which include the
decomposition of wastes in landfills, rice cultivation, ruminant digestion, and domestic livestock manure management.
Methane is a more active greenhouse gas than carbon dioxide but it is much less abundant in the atmosphere.
 4. Nitrous oxide (N2O) - Nitrous oxide is a powerful greenhouse gas produced due to soil cultivation practices, especially
the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning. NO
concentrations have risen by approximately 20% since the start of the Industrial Revolution, and has rapidly increased by
the end of the 1900s.
5. Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs),
perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), or F-gases
6.Sulfur hexafluoride (SF6) or F-gases - are used as coolants, foaming agents, fire extinguishers, solvents,
pesticides, and aerosol propellants. Unlike water vapor, F-gases have a long atmospheric lifetime, and
emissions of these can affect the climate for long period of time.
Greenhouse Gas Emissions and Economic Activities

Since the Industrial Revolution began in 1750, human activities have contributed tremendously to
climate change by adding carbon dioxide and other heat-trapping gases to the atmosphere. These greenhouse
gas emissions increased the greenhouse effect and resulted to an increase in the temperature of the Earth's
surface. The emission of greenhouse gas from fossil fuel burning is the primary human activity that affects the
rate of climate change.
Global Greenhouse Emissions
Greenhouse Gas Percentage of Emission
Carbon Dioxide (Fossil fuel processes) 65%
Methane 16%
Carbon dioxide (Forestry and other land use) 11%
Nitrous Oxide 6%
F-gases 2%

At the global scale, carbon dioxide released from fossil fuels burning and industrial processes are mostly
emitted in the atmosphere (65%). It is followed by methane emission (16%) which comes from agricultural
activities, waste management, energy use, and biomass burning. Carbon dioxide emission from forestry and
other land use (11%) places third. Nitrous oxide emission (N 2O) is fourth with 6% emission rate. Nitrous oxide
emission comes from fertilizer use, and biomass burning. F-gases placed fifth with 2% emission rate. The
emission of F-gases come from industrial processes, refrigeration, and the use of a variety of consumer
products which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF 6).
Global Emission by Economic Sector
Economic Sector Percentage of Greenhouse Gas Emission
Electricity and Heart Production 25%
Agriculture, Forestry, and other Land use 24%
Transportation 14%
Industry 21%
Other energy 14%
Buildings 6%

The global greenhouse gas emissions can also be explained by looking at the percentage of its omission in
different consumption and production activities. The electricity and heat production sector emits 25% of
greenhouse gases in 2O10, sources of which come from the burning of coal, natural gas, and oil for electricity
and heat. The Industry sector constitutes about 21% of 2010 global greenhouse gas emissions. Emissions from
the industry sector are derived from the burning of fossil fuels in energy facilities. This sector also includes
emissions from chemical, metallurgical, and mineral transformation processes that are not associated with
energy consumption It also emitted due to waste management activities. The third sector with e forestry the
highest greenhouse gas emission percentage is the agriculture, and other land use sector which is about 24%
of the global greenhouse gas emissions. The greenhouse gas emissions from this sector originate from the
cultivation of crops, livestock domestication, and deforestation. The transportation sector emits 14% of
greenhouse gases and it primarily originates from fossil fuels burned for road, rail, air, and marine
transportation. Almost 95% of the world's transportation energy comes from petroleum based fuels, largely
gasoline and diesel; Buildings release 6% of greenhouse gas. The greenhouse gas emissions from this sector
are derived from on-site energy generation and burning fuels for heat in buildings. Other energy sectors
constitute 10% of greenhouse gas emissions. These ten percent refer to all emissions from the energy sector
which is not directly connected to electricity or heat production. These include fuel extraction, refining
processing, and transportation.
 In 2011, China, the United States, the European Union, India, the Russian Federation, Japan, and
Canada are the top carbon dioxide emitters of the world. These data include carbon dioxide emissions from
fossil fuel combustion, cement manufacturing, and gas flaring. Together, these sources represent a large
proportion of total global carbon dioxide emissions.

Global Carbon Dioxide Emissions from Fossil Fuel Combustion

and Some Industrial Processes in 2011

Country Percentage of Carbon Dioxide Emissions

China 28%
United States 16%
European Union 10%
India 6%
Russia 6%
Japan 4%
Other countries 30%

Which countries have the highest percentage of carbon dioxide emission?

GREENHOUSE GAS EMISSIONS AND TRENDS
Human activities also contributed to climate change. The largest known contribution comes from the
burning of fossil fuels, which releases carbon dioxide gas to the atmosphere. Greenhouse gases and aerosols
affect climate by altering incoming solar radiation and outgoing infrared (thermal) radiation that are part of
Earth's energy balance. The changes in the atmospheric abundance or properties of these gases and particles
can lead to the warming or cooling of the climate system. Since the start of the Industrial Revolution, the
overall effect of human activities on climate has been alarming. The human impact on climate during this era
greatly exceeds changes caused natural processes, such as solar changes and eruptions. Human by e omit four
principal greenhouse gases, namely, carbon dioxide (CO 2) methane (CH4), nitrous oxide (N2O) and the
halocarbons, a group of gases made up of fluorine, chlorine, and bromine. These gases gather in the
atmosphere and cause concentrations to increase with time.
The increase in emission of greenhouse gases are attributed to different The economic e activities.
Carbon dioxide omission increased due to the use of rules in transportation and in cement manufacture.
Deforestation releases carbon dioxide and reduces its intake by plants. Carbon dioxide is also released when
plant matter decays, Methane emission risen as a result of human activities related to agriculture, natural gas
distribution, and landfills. Methane is also released from natural processes that occur in wetlands. Nitrous
oxide is emitted due to fertilizer use and fossil fuel burning Natural processes in soil and the oceans also
release nitrous oxide.
Halocarbon gas concentrations have increased as a result of human activities Principal halocarbons
include the chlorofluorocarbons (e.g. CFC 11 and CFC-12), which were used mainly as refrigeration agents and
in other industrial processes. The presence of these gases in the atmosphere was discovered to cause the
depletion of the stratospheric ozone layer. Fortunately, the abundance of chlorofluorocarbon gases is
decreasing due to International regulations implemented to protect the ozone layer.
Ozone is a greenhouse gas that is repeatedly produced. Human activities have increased ozone
emission through the release of carbon monoxide, hydrocarbons, and nitrogen oxide which react chemically to
create ozone. These halocarbons destroy the ozone layer in the stratosphere.
Aerosols are small particles present in the atmosphere that have varying sizes, concentration, and chemical
compositions. Some aerosols are directly released into the atmosphere while others are formed from emitted
compounds. Aerosols are made up of naturally occurring compounds and particles emitted due to human
activities. Fossil fuel and biomass burning have increased aerosols containing sulfur compounds, organic
compounds, and black carbon or soot.
In the Philippines, greenhouse gas emissions have increased from 1994 1o 2000. Energy related
industries emitted the largest amount of carbon dioxide (CO 2) from 1994 to 2000. From 50,040.33 kilotons in
1994, it has eased to 69,667 kilotons six years later. It is followed by agriculture which released 37,002 kilotons
of CO in 2000 compared to about 33,128.57 kilotons in 1994. Waste and industrial processes placed third and
fourth in the list respectively. In the 2000 statistics, waste released 11,599 kilotons of CO, while industrial
processes released 7,094.78.
Since 1990, greenhouse gas emissions have increased by about seven percent in the United States.
Annually, the emissions can rise and fall due to economic changes, fuel prices, and other factors. In 2014, the
greenhouse gas emissions of the United States increased compared to its 2013 level. The increase was due to
a number of factors, namely, the cold winter conditions resulting to an increase in fuel demand in residential
and commercial sectors: an increase in transportation emissions resulting from a rise of vehicle miles traveled;
and an increase in industrial production across multiple sectors. All of these factors resulted to increases in the
industrial sector's gas emissions.

WHAT I HAVE LEARNED

Direction: Define the following terms in 2-3 sentences.
1. Greenhouse effect
2. Global warming
3. Climate Change
4. Carbon dioxide
5. Methane
6. Aerosols
7. Ozone
8. F-gases
9. Greenhouse gases
10. Fossil fuel

LEARNING ACTIVITY SHEET

Name:__________________________________________________________________________________
Grade and Section:__________________________________________________Date:__________________
Direction: Write a short editorial essay or position paper that will explain your stand on how the
consequences of one’s action affect the lives of others and the environment. Relate your answer to
the issue of climate change.
Criteria
Organization of thought - 15 points
Creativity - 10 points
Readability of handwriting - 5 points
Total - 30 points

REFLECTION
How would you explain the source of the different greenhouse gases? How do they contribute to climate
change?

REFERENCES
MELC (Most Essential learning Competency)
Trends, networks, and Critical Thinking in 21st Century Culture by Arliegh Ross D. Dela Cruz
Cecile C. Fadrigon and Napoleon M. Mabaquiao