LESSON 2.1: EARTH WEATHER AND CLIMATE
WEATHER
 refers to the short-term atmospheric conditions in a specific location over a period
of hours or a few days.
CLIMATE
 Is the average of all weather conditions of an area over a long period of time.
 It affects the world's biodiversity. Plant species, animal groups, and even the
population of insects are close to the type of climate of an area. As we all know,
each flora and fauna has its own requirements in terms of water, nutrients, and
even its habitat.
DIFFERENT TYPES OF SEASONS
SEASON – a period of the year that is distinguished by special climate condition.
1. Winter - The coldest season in the year.
2. Spring - is associated with the return of wildlife, the blooming of plants, and the start of
new growth.
3. Summer - The warmest season in the year, it is associated with hot temperature.
4. Autumn - associated with falling leaves, cooling temperatures, and the end of the
growing season.
5. Wet Season - is generally associated with rainy weather conditions.
6. Dry Season - is a time of year when there is typically very little rainfall and high
temperatures.
 In the Philippines, the wet season typically occurs from June to November, while the
dry season generally occurs from December to May.
DIFFERENT FACTORS AFFECTING CLIMATE
LATITUDE
 Is the geographic coordinate that specifies the north-south position of a point on the
surface of the earth. It is considered the single most important factor that
determines climate.
 It dictates the intensity and duration of sun exposure to the earth. Generally, the
farther away from the equator the region can be found, the lesser the energy that
reaches the ground at any point in time.
SPECIAL LINES OF LATITUDE
• EQUATOR – located at 0° latitude, divides the Earth into the Northern Hemisphere and the
Southern Hemisphere.
•TROPIC OF CANCER – located at approximately 23.5° north of the equator and represent the
northernmost point where the sun appears directly overhead at noon on the summer solstice.
•TROPIC OF CAPRICORN – located at approximately 23.5° south of the equator and marks the
southernmost point where the sun appears directly overhead at noon on the summer solstice.
•ARCTIC CIRCLE – located at approximately 66.5° north of the equator.
•ANTARCTIC CIRCLE - located at approximately 66.5° south of the equator.
THREE GENERAL CLIMATIC ZONES
CLIMATIC ZONE- refers to a specific region of the Earth’s surface with distinct climates.
1. ARCTIC (POLAR/FRIGID) ZONE
 found at 66.5°N of the North Pole
comprise the Arctic region; from 66.5°S to
the South Pole is the Antarctic.
 Places within the Arctic climate zones are
covered with permafrost. During summer,
this zone experiences continuous periods
of daylight, but the monthly temperature
struggles to rise above freezing point.
 In these regions, the sun hovers above the
horizon at midnight in the summer and
never rises at all, at times, during the
winter.
Earth’s climatic zone
2. TROPICAL (TORRID) ZONE
 refers to the zones within latitudes between 5/10° to 35°. The equatorial belt
experiences a non-arid climate with an average temperature above 18°C.
 Weather condition are hot and humid. Sunshine & rainfall are present, which allow
this zone to have a luxuriant vegetation.
THREE DISTINCTIVE TROPICAL CLIMATES:
 EQUATORIAL – are found near the equator and experience high levels of
precipitation and humidity consistently, with no clear dry or wet season.
 TROPICAL CONTINENTAL – during the wet season, these regions experience
significant rainfall, while dry season has less precipitation.
 HOT DESERTS – are known for their extremely high temperatures and very little
rainfall.
3. TEMPERATE ZONE
 refers to zones in a range of latitude between 40° and 60/70°. Unlike arctic and
tropic climates, this zone does not experience extremes of temperature and
precipitation.
TWO TYPES OF TEMPERATE CLIMATE:
 MARITIME CLIMATE is strongly affected by the oceans and has fairly steady
temperatures across the seasons.
 CONTINENTAL CLIMATE increases in land characterized by warmer summers and
colder winter due to the thermal inertia possessed by the land.
OCEAN CURRENT
 the continuous, predictable, directional movement of seawater driven by gravity,
wind (Coriolis Effect), and water density.
 Covering about 71% of the earth and with a capacity to absorb about twice as much
of the sun's radiation. World oceans are a major driving force of the climate change.
THREE MAIN PROCESSES THAT MAKES THE OCEAN CIRCULATE
1) TIDAL FORCE- caused by gravitational force or pull between the moon and earth.
2) WIND STRESS- also known as wind pattern which is affected by the rotation of earth
known as the coriolis effect.
3) DENSITY- cold and saltier water is denser than warm and salty water.
TWO CIRCULATION TYPE OF OCEAN CURRENTS
1) WIND-DRIVEN CIRCULATION
 forced by wind stress on the sea surface including a momentum exchange. It
dominates in the upper hundred meters from the sea surface.
 Wind patterns or wind stress is affected by the rotation of the earth which deflects
the direction of the wind to the right in the northern hemisphere and to the left in
the southern hemisphere which drive surface ocean currents.
2) THERMOHALINE CIRCULATION
 an overturning circulation in which water flows poleward near the surface and
subsequently converted into cold water that sinks and flows equatorward in the
interior.
 Thermohaline circulation also known as the "ocean conveyor belt" which moves a
massive current of water around the globe, from northern oceans to southern
oceans, and back again. Currents slowly turn over water in the entire ocean, from
top to bottom. It is somewhat like a giant conveyor belt, moving warm and saltier
surface waters downward and forcing cold, less salty, and nutrient-rich waters
upward to keep the surface water replenished with nutrients.
SOME THINGS TO KEEP IN MIND TO UNDERSTAND THE OCEAN CIRCULATION
•Water always flows down toward the lowest point.
•Water's density is determined by the water's temperature and salinity (amount of salt)
•Cold water is denser than warm water.
•Water with high salinity is denser than water with low salinity.
•Ocean water always moves toward an equilibrium, or balance. For example, if surface
water cools and becomes denser, it will sink. The warmer water below will rise to balance
out the missing surface water
 There is a pressing concerns that as more sea ice melts the influx of fresh water will
make the seas water less dense. In effect less denser will not be able to sink
therefore the water won't be able to circulate throughout the world, and
thermohaline circulation will stop that will drastically change the climate throughout
the world.
ALTITUDE
 Altitude is the elevation or distance above the mean sea level. Sea level is the level
of the sea at a particular time.
 Altitude affects temperature and
pressure. As altitude increases,
the corresponding temperature of
air decreases. As such, regions in
high altitudes experience low
temperatures. This observation
was verified in 1889 when C. Hart
Merriam completed his
documentary analysis dividing the
Colorado Plateau into various
levels called "life zones."
PREVAILING WIND
 are the dominant winds that consistently blow in a particular direction over a
specific region. They are influenced by global atmospheric circulation patterns and
the Earth’s rotation.
 These winds play a crucial role in shaping climate by redistributing heat and
moisture. Prevailing winds blow more often from a certain direction than from any
other Warm air can hold more moisture than cold air does. As warm air rises, it cools;
hence, it cannot hold as much moisture. The moisture that warm air cannot hold
falls back to Earth as some form of precipitation.
RELIEF
 refers to the shape of the land's surface. It includes aspects, which means the
directions in which slope faces.
 Mountains form a natural barrier that causes air masses to rise. Windward mountain
slopes, facing moisture-bearing winds, usually receive more precipitation than either
the lower, more level mountain bases. This is because air moving up a mountain
slope expands and cools, reducing the amount of moisture needed for saturation.
Air that raises from the ground cools at a dry adiabatic lapse rate (DALR) which is
equal to 10°c/1,000m.
 Air moving down a mountain
compresses and warms, increasing
the amount of moisture possible in
the air. Eventually, it will reach an
altitude where the moisture in the
air condenses, forming clouds then
cools at a saturated adiabatic lapse
rate (SALR) which is about to 4.5°c/
1,000m.
Dry adiabatic rate
PROXIMITY TO WATER
 Water on Earth exists in three phases; gaseous, liquid and frozen phases. Bodies of
water such as ocean, rivers, & lakes have damping effect on the swing in
temperatures of coastal areas. They tend to store heat in warm periods and release
it into cold periods; hence, they are called HEAT SINKS.

THERMAL INERTIA – refers to the tendency of heat to transfer more slowly to some
material bodies than others, which creates an apparent lag between temperature
change between two material bodies. SPECIFIC HEAT ENERGY is the heat (energy)
that must be transferred to a material for one gram to experience a one degree rise
in temperature.
 CONVECTIVE CURRENTS – can occur anywhere as long as there is an uneven heating
of the Earth’s surface. They are most observable in areas with a landmass directly
adjacent to a large body of water.
SEA BREEZE
 During daytime, land heats faster
than water so the air over the
land becomes warmer and less
dense. It rises and is replaced by a
cooler, dense air flowing from
over the water.
LAND BREEZE
 During nighttime, land cools
faster than water as does the
corresponding air. In this case, the
warm air over the water rises and
is replaced by the cooler, denser
air from the land creating an
offshore wind.
SOLSTICES are the longest and shortest days of the year
 SUMMER SOLSTICE- takes place on 21st June. The Northern Hemisphere experiences
its longest day and shortest night.
 WINTER SOLSTICE- takes place on 22nd December. The southern Hemisphere
experiences its longest day and shortest night.
EQUINOXES occur when the day and night are equally as long.
 VERNAL EQUINOX (SPRING EQUINOX)
- occurs about March 20 or 21 in the Northern hemisphere and Sept. 22 or 23 in
the Southern hemisphere.
- the time at which the sun crosses the plane of the equator towards the relevant
hemisphere, making day and night of equal length.
 AUTUMNAL EQUINOX (FALL EQUINOX)
- occurs about Sept. 22 or 23 in the Northern Hemisphere and March 20 or 21 in
the Southern Hemisphere
- the time at which the sun crosses the plane of the equator away from the
relevant hemisphere, making day and night of equal length.
APHELION & PERIHELION
 APHELION - is the point of the Earth's orbit that is farthest away from the Sun. It
always happens in early July, about two weeks after the June solstice. The distance is
approximately 94.5 million miles or 152 million kilometers.
 PERIHELION - is the point of the Earth's orbit that is nearest to the Sun. This always
happens in early January, about two weeks after the December solstice. The
distance is approximately 91.4 million miles or 147 million kilometers.
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LESSON 2.2: GLOBAL CLIMATE CHANGE PHENOMENON
EARTH'S ATMOSPHERE - a thin blanket of air surrounding the Earth from all sides.
 CLIMATE CHANGE
- Refers to any significant change in the measure of climate lasting for an extended
period of time. It includes major changes in temperature, precipitation, or wind
patterns, among others effect, that occur over several decades or longer.
 GLOBAL WARMING
- Refers to the recent and ongoing rise in global average temperature near the Earth’s
surface.
•EFFECTS OF GLOBAL WARMING: Heat waves, wildfire, flood, and drought.
•PREVENTION OF GLOBAL WARMING: Planting more, reducing waste generation, using
more renewable energy, reducing the use of products which generate greenhouse gases
 GREENHOUSE EFFECT- a warning that results when the atmosphere traps heat
radiating from the earth toward space.
MAIN INDICATORS OF CLIMATE CHANGE
Based on the comprehensive research conducted by National Oceanic and Atmosphere
Administration (NOAA), there are ten climate change indicators.
SEVEN INDICATORS ARE RISING: air temperature over land, sea-surface temperature, air
temperature over oceans, sea level, ocean heat, humidity, tropospheric temperature in the
active-weather layer of the atmosphere closest to the earth's surface.
THREE OTHER INDICATORS ARE DECLINING: Arctic sea ice, glaciers, and spring snow cover
in the Northern Hemisphere.
 The earth's average temperature has risen by 1.4°F over the past century and it is
projected to rise another 2° to 11.5°F over the next hundred years.
CAUSES OF CLIMATE CHANGE
GREENHOUSE GAS(GHG) is a gas in the atmosphere that absorbs and emits radiation within
the thermal infrared range. This process is the fundamental cause of the greenhouse effect.
FIVE GASES RESPONSIBLE FOR 99.5% OF THE GREENHOUSE EFFECT:
1. WATER VAPOR (H20) - is the most prevalent of the GHG.
 Source: primarily arises from natural processes like evaporation from oceans, rivers,
and lakes.
 Impact: acts as feedback to the climate; as temperature rise, it can be increase and
intensifying the greenhouse effect.
 Role in climate change: acts as a natural greenhouse gas, but its concentration is
largely influenced by atmospheric conditions.
2. CARBON DIOXIDE (CO2) - is a naturally occurring chemical compound that is released
through natural processes.
 Source: respiration, volcanic eruptions, industrialization, and rapid population
growth.


Impacts: leads to long-term global warming, climate shifts, and ocean acidification.
Role in climate change: major contributor to the enhanced greenhouse effect by
trapping outgoing infrared radiation.
3. METHANE (CH4) is a hydrocarbon gas produced through natural sources and human
activities. Remains in the atmosphere for 11-12years, less time than most other GHG.
 Source: produced by rice cultivation, cattle and sheep ranching, decaying materials
in landfill, coal mining, oil drilling, and leaky gas pipelines.
 Impact: contributes significantly to short-term warming and influencing climate
patterns.
 Role in climate change: a potent greenhouse gas and more effective at trapping heat
than carbon dioxide.
4. NITROUS OXIDE (N20) - commonly known as laughing gas, is a chemical compound used
as an oxidizer in rocketry and in motor racing to increase the power output of engines. It is
the main naturally occurring regulator of stratospheric zone.
 Source: human activities such as fossil fuel combustion, wastewater management,
and industrial processes.
 Impact: contributes to global warming and has implications for both climate and the
ozone layer.
 Role in climate change: a powerful greenhouse gas with a longer atmospheric
lifetime than methane.
5. CHLOROFLUOROCARBONS (CFCS) - are organic compounds that contain carbon, chlorine,
and fluorine. Chlorine, an active substance in this compound was introduced to the ozone
layer that unfortunately led to the depletion of the latter.
 Source: synthetic compounds used in refrigerator and freezer, air conditioner, and
aerosol propellants.
 Impact: contribute to global warming and harmful to ozone layer which affects both
climate and environmental health.
 Role in climate change: potent greenhouse gases with global warming potential.
CLIMATE CHANGE IN FOCUS: IMPACTS AND THREATS
1. Rising Temperature - Based on the Fourth Assessment Report of the Intergovernmental
Panel on Climate Change (IPCC, 2007), an increasing rate of warming has particularly taken
place over the last 25 years and 11 of the 12 warmest years have occurred in the past 12
years.
It was estimated that the earth
could warm from a minimum of
1.8°C to as much as 4°C rise in
global average temperature by
2100.
In the Philippines, the average
annual mean temperature is
projected suppose and 1.7°C by
2050.
2. Shrinking Ice Sheets - Data from NASA's Gravity Recovery and Climate Experiment
revealed that Greenland lost 150 to
250 km³ of ice per year between
2002 and 2006 while Antarctica lost
about 152 km³ during the same
period. Based on NASA's ICESat data,
they found the trend alarming.
In total, the scientists calculated
that the ice pack shrank by 57%
between 2004 and 2008, thinning by
2.2 feet.
3. Sea Level Rise - Globally, sea level rose about 17 cm in the last century Sea level is
measured relative to a land-based tide-gauge benchmark.
2 MAIN FACTORSTHAT CONTRIBUTED TO THE OBSERVED SEA LEVEL RISE:
1. thermal expansion, which can
be attributed to the fact that
warm water expands.
2. The contribution of water
level from melting of landbased glaciers in Greenland
and Antarctica
4. Biodiversity Depletion - due to rising temperature, extreme weather conditions and
changing vegetation become usual in most of the places in the world. As a result, animal
species are forced to migrate to new, cooler areas in order to survive.
5. Ocean Acidification- is caused by carbon emissions which, when not controlled, will pose
serious threat to biodiversity and marine species (coral reefs and fisheries). When there is
more CO₂ in the atmosphere, there is also an abundant amount of this compound in the
ocean. When CO₂ reacts with water it produces a weak acid called carbonic acid, changing
the seawater chemistry.
6. Extreme Weather - Scientists believe that the increased intensity and frequency of two
phenomena, namely, El Niño and La Niña, in recent years are due to global warming.
Further studies claim that higher global temperature might be increasing the rate of
evaporation from land and ocean that leads to drought in some part of the world. With a
very high evaporation rate, intensified storms and floods associated with El Niño occur.

La Niña - It is a climate pattern that describes the cooling of surface-waters along
the tropical west coast of South America.

El Niño - It is a phenomenon that occurs when unusually warm ocean water piles up
along the equatorial west coast of South America.
WAYS TO MITIGATE THE EFFECTS OF CLIMATE CHANGE
CLIMATE CHANGE MITIGATION refers to any action focused to reduce the intensity of
radiative forcing so as to lessen the effects of global warming.
1. Increasing carbon sequestration and conservation. This involves finding ways to capture
and store carbon dioxide from the atmosphere. Examples include using carbon sinks,
improving vegetation management or sustainable land management (SLM) techniques.
2. Use of bioenergy. Instead of relying on fossil fuels or wood for energy, renewable
resources can be used to produce bioenergy. This not only reduces emissions but also helps
protect endangered woodlands and forests thereby solving another problem known as land
degradation.
3. Reduced fertilizer use. Chemical fertilizer called inorganic or synthetic fertilizers are
produced synthetic mean making them nondegradable. They are composed of one or more
elements which when applied to vegetation, it may result in eutrophication, increase acidity
and loss of bacteria in the soil. To reduce these harmful effects, proper timing of fertilizer
application and utilization of notification inhibitors and existing nitrogen from organic
matter are advised.
4. Anaerobic digestion of waste. Methane (CH4) is an identified greenhouse gas that
produced through natural decay waste of water, crop waste, and animal waste. To reduce
its emissions, waters can be collected and stored in anaerobic digesters.
5. Improve energy efficiency. Utilizing domestic energy sources, making mass transit more
extensive, economical and user friendly, developing and disseminating practical energy
conservation packages for the general population and industry sectors such as agriculture,
trucking, airline and fishing etc., setting advisory guidelines for industry and consumer in
the use of Energy star qualified products and recycling items considerately are some
practices that would improve energy use efficiency.