Climate Change 2
Climate Change 2
Climate Change 2
REPRESENTING GROUP 2
BY -
Lalhruaisanga
Vanlalthlana Chawngthu
Lalhmingmawii
Lalsangkimi
K. Rosangliana
INTRODUCTION
• Climate change is the change in our weather patterns that are occurring
because of an increase in the earth's average temperature.
• Climate change may result from both natural and human causes though
the human causes appear to be increasingly responsible for climate
change over the past few decades
• Climate change is one of the most formidable developmental challenges faced by
humanity today.
• The global climate is now changing faster than at any point of time in human
civilisation.
• Climate change will affect, in profoundly adverse way, some of the most
fundamental determinants of health: food, air and water, adequate shelter and
freedom from disease.
• The Earth's climate, although relatively stable for the past 10,000 years or so, has
always been changing, mainly due to natural causes such as volcanic activity.
• But since the 1900s more rapid changes have taken place and these are thought to
be mainly man-made
• Global warming mean temperatures increased by 0.74° C during last 100 years and
by the year 2 100 best estimates predict between a 1.8° C and 4° C rise in average
global temperature. Although it could possibly be as high as 6.4°C
NATURAL CAUSES
Natural Causes
• The causes of climate change is divided into natural causes and
anthropogenic causes (Man-made).
• Natural causes:
These have been caused by many natural factors, including changes in the sun,
emissions from volcanoes, variations in Earth’s orbit and levels of
carbon dioxide (CO2).
• Anthropogenic causes:
Burning of fossil fuels, cutting down forests and farming livestock are increasingly
influencing the climate and the earth's temperature.
Strength of the sun:
Sun-Almost all of the energy that affects the climate on Earth originates
from the Sun.
Only some of the solar energy intercepted at the top of the atmosphere
passes through to the Earth, some of it is reflected back into space and
some is absorbed by the atmosphere.
The energy output of the Sun is not constant, it varies over time and this has an
impact on our climate.
Changes in earth’s orbit, axial tilt and precession:
The three changes in the Earth’s orbit around the Sun — eccentricity, axial tilt, and
precession are collectively called ‘Milankovitch cycles’.
The time period between these changes can be tens of thousands of years
Milankovitch’s three cycles:
• The Earth’s orbit around the Sun is an ellipse but it isn’t always the same shape of
ellipse. Sometimes, it is almost circular.
• The Earth moves closer and further away from the Sun in its orbit.
• When the Earth is closer to the Sun, our climate is warmer and this cycle also
affects the length of the seasons
Circular orbit(left) and Elliptical orbit(right). When the earth is closer to the
Sun, its climate is warmer
The Earth’s axial tilt:
• The Earth wobbles on its axis, much like a spinning top that is slowing down. This is
called ‘precession’ and is caused by the gravitational pull of the Moon and the Sun
upon the Earth.
• Which make changes on North pole where it points to in the sky, but over
thousands of years the axis moves around in a circle and points at different parts of
the sky.
• It impacts on the seasonal contrasts between hemispheres and the timing of the
seasons
Greenhouse Gases:
Greenhouse gases include carbon dioxide (CO2), methane (CH4) and water vapour
(H2O).
H2O stays in the atmosphere for just a few days, it is the most abundant
greenhouse gas in the atmosphere
CH4 stays in the atmosphere for about nine years until it is removed by oxidation
into CO2 and water.
CO2 stays in the atmosphere much longer, from years to centuries, contributing to
longer periods of warming.
These gases trap solar radiation in the Earth’s atmosphere, making the climate
warmer.
Changes in Ocean currents:
As the oceans absorb more heat from the atmosphere, sea surface temperature
increases and the ocean circulation patterns that transport warm and cold water
around the globe change.
The direction of these currents can shift so that different areas become warmer or
cooler.
As oceans store a large amount of heat, even small changes in ocean currents can
have a large effect on global climate.
Natural Causes
Volcanoes affect the climate through the gases and particles thrown into the
atmosphere.
The effect of volcanic gases and dust may warm or cool the Earth’s surface,
depending on how sunlight interacts with the volcanic material.
During major explosive volcanic eruptions, large amounts of volcanic gas, aerosol
droplets and ash are released.
In the present day, the contribution of volcanic emissions of CO2 into the
atmosphere is very small; equivalent to about one per cent of anthropogenic
(caused by humans) emissions.
Changes in land cover:
Vegetation absorbs CO2 and this can buffer some of the effects of global warming.
On the other hand, desertification amplifies global warming through the release of
CO2 because of the decrease in vegetation cover
ANTHROPOGENIC
CAUSES
Man made/Anthropogenic:
Air pollution is caused by fertiliser use, livestock production, and certain industrial
processes that release fluorinated gases.
Pollutants in the air can produce serious environmental issues and contribute to
climate change.
The major concerns include:
i. The ability of pollutants to trap too much heat in the atmosphere.
ii. The mixture of gases with moisture in the atmosphere which produces damaging
acid rain.
iii. The increase in unnatural ozone levels.
iv. The presence of particles in the atmosphere that block sunlight.
Fig. Air pollution
3.DEFORESTATION :
This can include clearing the land for agriculture or grazing, or using the timber for
fuel, construction or manufacturing.
The trees absorb Carbin dioxide and release Oxygen in the air. But, due to
deforestation the content of Carbondioxide has increased in the atmosphere,
leading to warm air or rise in temperature leading to global climate changes.
Fig. Deforestation
4.MINING:
Mining activities thus causes affect weather patterns and climate stability which
can affect future water supplies and is responsible for global warming
Fig. Mining
EFFECTS OF
CLIMATE CHANGE
Effects of Climate change
• Warmer temperatures over time are changing weather patterns and
disrupting the usual balance of nature, posing many risks to human
beings and all other forms of life on Earth.
• Because the Earth is a system, where everything is connected, changes
in one area often influence changes in all others. The consequences of
climate change now include:
• intense droughts
• water scarcity
• severe fires
• rising sea levels
• flooding
• Loss of species
Effects of Climate change
• Climate change disrupts weather patterns and causes extreme weather events
become more common. These include hurricane activity, droughts and floods.
Effects of Climate change
Percentage Species
2°C 1.5°C
Percentage Coral
80 70 % 15
60
Loss
10
Loss
8
40 6
5 4
20
0 0
1.5 insects plants vertebrates
Temperature Rise (°C)
From the given data if the global temperature rises And from this data we can understand how climate change
for just 1.5 C almost 70% of the coral reef will be affects the species population.. if the temperature rises for
just 1.5 C.. 6% of insect , 8% of plant and 4% of vertebrates will
lost.
be lost
. A stable climate supports this process and allows The increase in global temperatures is causing a
living things to thrive. If the climate changes reduction in sea ice. This causes problems for animals
quickly, organisms don’t have enough time to adapt that depend on the ice to hunt, mate and sleep.
to new conditions and may no longer be able to
survive.
PREVENTIVE MEASURES
OF CLIMATE CHANGE
Preventive Measures of Climate change