Post on 18-Aug-2015
Welcome
P.N.Harathi
TAD/14-05
Dept. Of Entomology
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a threat?
Is Global warming
Definition Global warming is defined as an increase in the average
temperature of the Earth's atmosphere, especially a sustained increase great enough to cause changes in the global climate’.
Green House effect The global warming potential (GWP) of a gas is defined
as the "radiative forcing" ( the additional radiative power that the gas is sending back to the ground) of a given quantity of gas, cumulated over a given period, generally 100 years.
This value is actually never given as an absolute figure, but relatively to CO2. The GWP of a gas is therefore "how much more" (or how much less) it "enhances the greenhouse effect over 100 years" (that is how much additional energy it sends back to the ground) compared to a similar quantity of CO2 emitted at the same time. 3
Current greenhouse gas concentrations
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GasPre-1750
troposphericconc.
Recenttropospheric
conc.
Absolute increase
since 1750
Percentageincrease
since 1750
Increasedradiative forcing(W/m2)
Carbon dioxide
280 ppm 395.4 ppm 115.4 ppm 41.2% 1.88
Methane 700 ppb 1893 ppb 1193 ppb 170.4% 0.49
Nitrous oxide
270 ppb326 ppb 56 ppb 20.7%
0.17
Tropospheric
ozone
237 ppb 337 ppb 100 ppb 42% 0.4
Global Greenhouse Gas Emissions
Source: Intergovernmental Panel for Climate Change
Global Greenhouse Gas Emissions by source
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Important Green house gases How it’s produced Avg. Life Time
CO2 Burning of fossil fuels, solid waste, and trees and wood products. Changes in land use also play a role. Deforestation and soil degradation add carbon dioxide to the atmosphere, while forest regrowth takes it out of the atmosphere
100 years
CH4 Production and transport of coal, natural gas, and oil. livestock and agricultural practices and from the anaerobic decay of organic waste in municipal solid waste landfills.
12 Years
N2o Emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.
114 years
CFCs A group of gases that includes hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride, among other chemicals. These gases are emitted from a variety of industrial processes and commercial and household uses, and do not occur naturally. Sometimes used as substitutes for ozone-depleting substances such as chlorofluorocarbons (CFCs).
A few weeks to thousands of years
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Global warming
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How Global Warming Works
Fossil fuels (coal, oil, natural gas)
Carbon Dioxide (CO2)
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Global warming
climatic events of the past 150 years have revealed that the temperatures have risen all over the globe, with the warming occurring in two phases. The first phase was from 1919 to 1940, with an average temperature gain of 0.35°C, and the second phase was from 1970 to the present, exhibiting temperature gains of 0.55°C.
Records show that the past 25 years have been the warmest time of the past 5 centuries.
Red colour: Severe Global warming
Blue colour: < Normal temperatures9
How is global warming measured?
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An Ice core is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Green land or from high mountain glaciers else where.
when entrapped carbon dioxide levels are high, the temperature goes up too.
Scientists use the ratio of heavy to normal water in ice layers to estimate average temperatures at the time the ice was made
ICE CORE DATA
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Ice core
12Ice at the South Pole contains air bubbles that are up to
800 000 years old.
Antarctic Ice-Core Stations
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CO2 Atmospheric Measurements
CO2 Measurements Since 1958 – Mauna Loa, Hawaii14
Argo float
15Deploying a robotic Argo ocean-profiling float.
Greed is the cause of global warming
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Burning of Fossil Fuels
Pollution from coal, natural gas, and oilPollution from coal, natural gas, and oilPollution from coal, natural gas, and oil 17
Effects of Global Warming
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What’s the proof that global warming is taking place?
THE TOP FLOODS IN INDIA’S HISTORY
Year Name Death People affected
1987 Bihar 1400 people 5000 animal dead
29 millon people
2005 Maharashtra 5000 people
2005 Gujarat < 123 (11 days) 2,50,000
2007 South Asian 2000 (> 15 days) 30 million
2009 K, Ke, Ori, G, NE
200 Million homes
2010 Ladakh 255 133 crores
2011 Indian Ker, WB, Bihar, Assam
> 10 million people
2012 Northern Indian
Assam 27 9 lakh people
Ut. K, H P and Jammu, resulting in landslides, cloud bursts and flash floods.
34 Hundreds
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People evacuated from their homes due to the incessant floods in India wade in the waters, searching for a place to
make camp during 2009
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Drought
Of the total agricultural land in India, about 68% is prone to drought of which 33% is chronically drought prone, receiving rainfall of less than 750mm per year. This is particularly the states of Maharashtra, Gujarat, Rajasthan, Karnataka, Andhra Pradesh and Orissa. The World Record Of Drought Was In 2000 in Rajasthan, India. 22
Portage Glacier
1914 2004
• Alaska
Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org
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Colorado River
• Arizona
June 2002 Dec 2003
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Arctic sea ice melting away
This photograph shows the extent of sea ice in the summer of 1983.
Photo: NASA/Goddard Space Flight Center Scientific Visualisation Studio
Satellite photos show that by 2007 the extent of summer sea ice was greatly reduced
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Consequences of Global warming
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Its in our hands
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We are running out of time
Act now before its too late
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What’s being done now to reduce our emissions?
Solar Power Wind Power Fuel-Efficiency 30
Simple Things To Do
Turn off your computer or the TV when you’re not using it.
Take shorter showers. Heating water uses energy.
Keep rooms cool by closing the blinds, shades, or curtains.
Turn off the lights when you leave a room.
Use compact fluorescent bulbs.
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Simple Things To Do
Dress lightly when it’s hot. Instead of turning up
the air conditioning, use a fan.
Dress warmly when it’s cold instead of turning up the heat.
Offer to help your parents keep the air filters on
your AC and furnace clean.
Walk short distances instead of asking for a ride in the car.
Plant a tree. Recycle.32
Each one Plant one
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Thank you34