Global warming is caused by heat-trapping gases like carbon dioxide and methane that are emitted through human activities like burning fossil fuels and deforestation. These gases trap heat in the atmosphere and cause Earth's surface temperature to rise, disrupting climate patterns. Effects of global warming include extreme heat, rising sea levels, more intense storms, droughts, and declining crop yields. International efforts to address global warming include the UN Framework Convention on Climate Change and its Kyoto Protocol that aim to reduce greenhouse gas emissions. Individual actions like conserving energy and planting trees can also help mitigate the problem.
3. WHAT IS GLOBAL
WARMING ???
an average increase in near the Earth’s surface and in
the troposphere, which can contribute to changes in
global climate patterns
Global warming is A rise in temperature of the Earth caused by
emissions of carbon dioxide and other heat-trapping gases that
are emitted primarily by the burning of fossil fuels and the
clearing of forests. These gases remain in our atmosphere for
decades or even centuries.
The atmosphere around us is made up of gases. Some of these gases
function like the panes of a greenhouse: they let some radiation from
the sun in but also retain heat in the atmosphere, that is: they don't
let all radiation back out. As a result of this natural effect, it is warmer
on Earth than it would be without these heat-trapping gases.This is
called the greenhouse effect.
4. Causes of global warming
• Ozone hole
• heat-trapping-gases
• aerosol emissions
• over population
• overuse of energy
• economic growth
• land use changes
• Burning of fossil fuels
• Cement manufacture
• Deforestation
OZONE HOLE
Each year for the past few decades
during the Southern Hemisphere spring,
chemical reactions involving chlorine
cause ozone in the southern polar
region to be destroyed rapidly and severely.
This depletion is known as the “ozone hole”.
5. EFFECT OF GLOBAL WARMING
extreme heat
drought,
rising sea levels,
higher-intensity tropical storms
risk with our coastal property and resources,
questionable livability of our cities in summer,
Lower productivity of farms, forests, and fisheries.
Changing climate conditions
severe stress on forests
6. Changing climate conditions
The ranges and abundance of plants and animals
could change dramatically under changing
climate conditions, and some of them are
likely to be unable to adapt or migrate
to new locations.
Drought Flood
severe stress on forests
Possible severe stress on forests
due to rapid and greater warming
7. serious human health impacts
Increasing heat stress, Worsening air pollution,
Declining water quality, Spread of infectious diseases
Sunburn poor people suffer from sun stroke
Sea level rise
Sea level could rise by 3.5 to 34.6 inches between 1990 and 2100,
making coastal groundwater saltier,endangering wetlands, and
inundating valuable land and coastal communities
8. Agricultural shift and decline in crop yeild:
AN INCREASE IN SURFACE TEMPERATURE BY 1 DEGREE CENTIGRADE
MAY ADVERSELY AFFECT THE WORLD FOOD PRODUCTION BECAUSE
OF AGRICULTURAL SHIFT AND LOWER CROP PRODUCTIVITY
LOSS IN BIODIVERSITY:TEMPERATURE RANGE.THE PREDICTED
WARMING IS MORE LIKELY TO SHIFT THE TEMPERTURE CHANGES.THE PLANTS
AND ANIMALS FAILED TO ADJUST WITH MIGRATION AND ADAPTATION STRESSES
AND LEADS TO LOSS IN BIODIVERSITY MOST PLANT AND ANIMAL SPECIES THRIVE
AND GROW ON A SPECIFIC
9. GREEN HOUSE
EFFECT
A GREEN HOUSE IS A HOUSE WITH ROOF AND WALLS MADE OF
TRANSPARENT GLASS.GREENHOUSE ARE CONSTRUCTED IN COLD REGIONS
TO GROW PLANTS,VEGETABLES,AND FLOWERS IN THEM WHICH WOULD
OTHERWISE NOT SURVIVE IN THE SEVERE COLD .
10. THE WORKING MECHANISM OF THE
GREENHOUSE EFFECT
THE EARTHS ATMOSPHERE PERMITS ABOUT 70 -75% OF RADIATION THAT HITS
IT TO REACH THE EARTH’S SURFACE THE REST BEING REFLECTED BACK INTO SPACE BY
CLOUDS,SNOW,AND ICE,THE RADIATION THAT REACHES THE EARTHS SURFACE HITS
BACK AND RISES,THE RADIATION ABSORBED BY GREENHOUSE GASES IS PARTLY
REFLECTED TO EARTHS SURFACE WHICH GETS HEATED UP.
11. Solar radiation at the frequencies of visible light largely passes through the atmosphere
to warm the planetary surface, which then emits this energy at the lower frequencies of
infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in
turn re-radiate much of the energy to the surface and lower atmosphere. The
mechanism is named after the effect of solar radiation passing through glass and
warming a greenhouse, but the way it retains heat is fundamentally different as a
greenhouse works by reducing airflow, isolating the warm air inside the structure so that
heat is not lost by convection . If an ideal thermally conductive blackbody was the same
distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C.
However, since the Earth reflects about 30% of the incoming sunlight, this idealized
planet's effective temperature (the temperature of a blackbody that would emit the same
amount of radiation) would be about −18 °C. The surface temperature of this
hypothetical planet is 33 °C below Earth's actual surface temperature of approximately
14 °C. The mechanism that produces this difference between the actual surface
temperature and the effective temperature is due to the atmosphere and is known as
the greenhouse effect.
GREEN HOUSE GASES
Carbon dioxide
Carbon dioxide (CO2) is one of those heat-trapping (greenhouse) gases
that have increased significantly in atmospheric concentration since
pre-industrial times and thus has raised the greatest concern.
Methane
Methane clathrate –compound containing large amounts of methane trapped in
crystals of ice
Nitrous oxide
12. Chlorofluoro-carbons(CFCs)
Tetrafluromethan
hexafluroethan
Sulphur hexafluoride (SF6)
Nitrogen trifluoride(NF3)
PREVENTION OF GLOBAL WARMING
• Save Electricity
Whenever we use electricity, we help put greenhouse gases into the air. By
turning off lights, the television, and the computer when you are through
with them, you can help a lot.
• Bike, Bus, and Walk
You can save energy by sometimes taking the bus, riding a bike, or walking.
• Talk to Your Family and Friends
Talk with your family and friends about climate change. Let them know
what you've learned.
• Plant Trees
Planting trees is fun and a great way to reduce greenhouse gases. Trees
absorb carbon dioxide, a greenhouse gas, from the air.
13. • Recycle
Recycle cans, bottles, plastic bags, and newspapers. When you recycle, you
send less trash to the landfill and you help save natural resources, like
trees, oil, and elements such as aluminum.
• When You Buy, Buy Cool Stuff
There are lots of ways we can improve the environment. One of the ways to
reduce the amount of greenhouse gases that we put into the air is to buy
products that don't use as much energy. By conserving energy, we help reduce
climate change and make the Earth a better place. Some products – like certain
cars and stereos – are made specially to save energy.
INTERNATIONAL EFFORTS
FEBRUARY 12-23,1979: The first World Climate Conference was held in
Geneva, Switzerland which concluded that anthropogenic carbon dioxide
could have a long term adverse impact in the global climate.
NOVEMBER 1988: An International Panel On Climate Change(IPCC) was
created by the United Nations Environment Programme(UNEP) and the
World Meteorological organisation(WMO).
NOVEMBER 1-7,1990: The second World Conference was held in Geneva.
137 participating countries agreed to negotiate a world climate treaty.
MAY 9, 1992: United Nations Framework Convention on climate
change(FCCC) was adopted at UN headquarters in New York, USA.
14. Montreal Protocol
• Treaty to limit the production and use of CFCs (signed in 1987)
• Signs of ozone depletion slowing down since then
Kyoto Protocol
• Treaty for developed countries to reduce emission of GHG
• Note that many countries did not accede due to profits from industries and
jobs for people
CONCLUSION
The world is temporarily affected by hot and cold climate periods.
The industrial revolution which started in 1875 changed weather
conditions. The world has a tendency to warm up. The
industrialisation and the increasing population density are forcing
governments to consume more fossil fuels and are affecting the
artificial green house gases’ fluctuation. Even if the usage of fossil
fuels could be prohibited, greenhouse gases extent in the
atmosphere is going to remain for hundred years. The emission of
greenhouse gases can’t be stopped, but some precautions must be
taken.
15. We can’t avoid all the consequences of global warming, but
committing ourselves to action today can help ensure our
children and grandchildren inherit a healthy world full of
opportunity…