Climate is the statistics of weather over long periods of time, while climate change refers to significant long-term shifts in weather patterns. The document discusses several lines of evidence for rapid climate change, including rising global temperatures and CO2 levels from ice core data. It also outlines theories for what causes climate change such as changes in Earth's orbit, the carbon dioxide level in the atmosphere, and variations in solar activity. The impacts of climate change include rising sea levels, stronger extreme weather events, and threatened plant and animal species.

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3.  Difference between weather and climate
 What is climate change
 Climate change: How do we know?
The evidence for rapid climate change
 Theories of climate change
 Impact of climate change
 Mitigation strategiesclimate change Ankita 3

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5.  Climate is the statistics of weather over long periods of time.
 It is measured by assessing the patterns of variation in
temperature, humidity, atmospheric pressure, wind,
precipitation, atmospheric particle count and other
meteorological variables in a given region over long periods of
time.
 Climate change is any significant long-term change in the
expected patterns of average weather of a region (or the whole
Earth) over a significant period of time.
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6. Scientific evidence for warming of the climate system is
unequivocal.
- Intergovernmental Panel on Climate Change
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7. This graph, based on the comparison of atmospheric samples contained in ice cores and
more recent direct measurements, provides evidence that atmospheric CO2 has increased
since the Industrial Revolution.
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8.  The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven
cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago
marking the beginning of the modern climate era — and of human civilization. Most of these climate
changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our
planet receives.
 Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture,
collecting many different types of information about our planet and its climate on a global scale. This body
of data, collected over many years, reveals the signals of a changing climate.
 The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th
century. Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis
of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must
cause the Earth to warm in response.
 Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate
responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean
sediments, coral reefs, and layers of sedimentary rocks. This ancient, or pa leo climate, evidence reveals
that current warming is occurring roughly ten times faster than the average rate of ice-age-recovery
warming.3
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9.  Global temperature rise
 Warming oceans
 Shrinking ice sheets
 Glacial retreat
 Decreased snow cover
 Sea level rise
 Declining Arctic sea ice
 Extreme events
 Ocean acidificationclimate change Ankita 9

10.  Astronomical or Orbital Theories
 Theories Involving the Displacement of Continents
-Wegener’s Continental Drift Theory
-Plate Tectonic Theory
 Theories Involving Change in the Composition of Atmosphere
-Carbon dioxide Theory
-Volcanic Dust Theory
 Geographical Theories
 Theories Involving a Change in Solar Radiation
Variable Sun Theory
Sunspot Cycle
Variations in Solar Constantclimate change Ankita 10

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13. Alfred Wegener proposed that the continents were once united into a single supercontinent
named Pangaea, meaning all earth in ancient Greek. He suggested that Pangaea broke up long
ago and that the continents then moved to their current positions. He called his hypothesis
continental drift.
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14. PLATETECTONICTHEORY
Tuzo Wilson put forth the idea that, “Earth’s crust is divided into approximately twenty (20) rigid
slabs called tectonic plates.” These tectonic plates are in continuous slow motion relative to each
other. Motion occurs along one of three types of boundaries bordering each plate.”
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15. CO2 content of the atmosphere play dominant
role in causing worldwide climate changes. This
gas transparent to incoming solar radiation, but
absorbs outgoing long-wave terrestrial
radiation. The absorbed terrestrial radiation is
radiated back to the earth’s surface. CO2 and
water vapour contents of the atmosphere being
the most important heat absorbers produce
what is called greenhouse effect. Thus it is
clear that any appreciable change in the
CO2content would bring about changes in the
lower atmosphere.
T.C. Chamberlin
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16. Volcanic dust , because of the size of its particles,
deflects light of the short wavelengths coming
from the sun. But long-wave terrestrial
radiation can easily pass through volcanic dust
may lower down the earth’s temperature to a
certain extent. The large amount of volcanic dust
present in the atmosphere is possibly one of the
causes of the ‘Little Ice Age’.
According to this theory, the ice ages are
supposed to be initiated during epochs of
frequent volcanic eruptions.
Example: the East Indian Volcano Krakatoa
(1883)
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17. Topographical changes of vast
magnitude bring about changes in the
oceanic and atmospheric circulations.
Such changes may greatly affect the
climate.
“In Chamberlin’s view,
the elevation of the land, the
modification of the currents of the air
and the oceans, and all that goes with
elevation as a topographic agency
constitute a primary cause of climate
changes”
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18. It is based on the idea that the sun is a
variable star and its radiant energy
undergoes changes through time. It holds
that increased output of solar radiation
leads to the warming of the atmosphere,
whereas its decline would result in
reduction of the atmospheric
temperature. Even though satellite
technology has made it possible to
measure the solar output of energy.climate change Ankita 18

19. SUNSPOTTHEORY
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20. Variations in the total output of
thermal energy by the sun
seems to be one of the most
significant causes of the world-
wide climatic change. Since the
atmosphere contains numerous
self-regulating mechanisms, it
is not necessary that a minor
increase or decrease in solar
radiation would cause a general
rise or fall in global
temperatures.
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21. Global warming is likely to be the greatest cause
of species extinctions this century. The
Intergovernmental Panel on Climate Change says
a 1.5°C average rise may put 20-30% of species at
risk of extinction. If the planet warms by more
than 2°C, most ecosystems will struggle.
Many of the world’s threatened species live in
areas that will be severely affected by climate
change. And climate change is happening too
quickly for many species to adapt.
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22. Climate change is amplified in the polar regions.
The earth’s north and south extremities are crucial
for regulating our planet’s climate and are
particularly vulnerable to the impacts of global
warming, which has global consequences.
The Antarctic ice sheet is the largest single mass of
ice on earth, accounting for around 90% of all fresh
water on the earth's surface and spanning almost 14
million sq. km. Parts of the west Antarctic Peninsula
are among the fastest-warming places on earth.
Even small-scale melting is likely to have significant
effects on global sea level rise.
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23. Oceans are vital ‘carbon sinks’, meaning that
they absorb huge amounts of carbon dioxide,
preventing it from reaching the upper
atmosphere. Increased water temperatures and
higher carbon dioxide concentrations than
normal, which make oceans more acidic, are
already having an impact on oceans. Coral
reefs are projected to decline by a further 70-
90% at 1.5°C. At a warming of 2°C virtually all
coral reefs will be lost. It’s not only a tragedy
for wildlife: around half a billion people rely on
fish from coral reefs as their main source of
protein.
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24. Impacts vary in different kinds of forests.
Sub-Arctic boreal forests are likely to be
particularly badly affected, with tree lines
gradually retreating north as temperatures
rise. In tropical forests such as the
Amazon, where there’s abundant
biodiversity, even modest levels of climate
change can cause high levels of extinction.
Dying trees emit their stores of carbon
dioxide, adding to atmospheric
greenhouse gases and setting us on a
course for runaway global warming.
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25. Climate change is having serious impacts on the
world’s water systems through more flooding and
droughts. Warmer air can hold a higher water
content, which makes rainfall patterns more
extreme. In mountainous regions, melting glaciers
are impacting on freshwater ecosystems. Himalayan
glaciers feed great Asian rivers such as the Yangtze,
Yellow, Ganges, Mekong and Indus. Over a billion
people rely on these glaciers for drinking water,
sanitation, agriculture and hydroelectric power.
Climate change only exacerbates the problem and
makes this worse.
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26. Climate change affects all the three aspects of food security:
availability, access and absorption. When production
decreases, availability of food decreases. Climate change hits
poor the most. They don’t have income to buy the food, so
their access to it is affected. This, in turn, has an impact on
health and affects absorption. rice, wheat, maize and
sorghum are the worst hit by this phenomenon. By 2030, rice
and wheat are likely to see about 6-10 per cent decrease in
yields. crops like potatoes, soybean, chickpea and mustard,
on which climate change will have a neutral or positive
impact.
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28.  Carbon sequestration
 Carbon sink
 carbon credit
 Carbon offsetting
 Carbon tax
 Geo-engineering
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29. “Carbon sequestration” describes the process of capture
and long-term storage of atmospheric carbon dioxide (CO2)
in a stable state.
When carbon is sequestered directly in the soil, inorganic
chemical reactions convert CO2 into inorganic carbon
compounds such as calcium and magnesium carbonates.
Direct carbon sequestration occurs in plants as they
photosynthesize atmospheric CO2 into biomass, which
means it is stored in “sinks” instead of being released into
Earth’s atmosphere. Subsequently, some of this plant
biomass is also indirectly sequestered as soil organic carbon
(SOC) during decomposition processes.
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30. A carbon sink is anything that absorbs more carbon
than it releases as carbon dioxide. European forests
are currently a net carbon sink as they take in
more carbon than they emit.carbon sinks are natural
(oceans and forests) and artificial deposits (certain
technologies and chemicals) absorb and capture
carbon dioxide (CO2) from the atmosphere and
reduce its concentration in the air. Oceans are
considered the main natural carbon sinks, as they are
capable of absorbing about 50% of the carbon
emitted into the atmosphere. In particular, plankton,
corals, fish, algae and other photosynthetic bacteria
are responsible for this capture.
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31. The United Nations' Intergovernmental Panel on
Climate Change (IPCC) developed a carbon credit
proposal as a market-oriented mechanism to slow
worldwide carbon emissions. A carbon credit is
a permit or certificate allowing the holder, such as a
company, to emit carbon dioxide or the equivalent
amount of a different greenhouse gas (tCO2e The
credit limits the emission to a mass equal to one ton
of carbon dioxide. The ultimate goal of carbon
credits is to reduce the emission of greenhouse gases
into the atmosphere.
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32. Carbon offsetting is
the action or process of
compensating for carbon
dioxide emissions arising
from industrial or other
human activity, by
participating in schemes
designed to make
equivalent reductions of
carbon dioxide in the
atmosphere.
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33.  A carbon tax is the core policy for
reducing and eventually
eliminating the use of fossil fuels
whose combustion is destabilizing
and destroying our climate.
 A carbon tax is a way to have
users of carbon fuels pay for the
climate damage caused by
releasing carbon dioxide into the
atmosphere.
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