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Climate change and
Water resources
Changes are being seen around the world
Upsala glacier, Patagonia
1928
2004
Source: Greenpeace
Pederson Glacier (Alaska)
Larsen B ice shelf, West Antarctica
Source: NASA
3250 square km of ice 220 m thick broke off3250 square km of ice 220 m thick broke off
Sea levels are rising
Source: http://www.flickr.com/photos/go_greener_oz/3047060508/
Source: Greenpeace
Drought in Amazon river, 2005
All is not well
Why is this happening?
Source: Vital Climate Graphics, Grid Arendal / UNEP
Gases like carbon dioxide are essential for life on Earth.
They trap some of the heat (infra-red radiations) leaving the Earth. Without them, Earth’s average temperature would be -200 C
They are called
Green House Gases
(GHGs)
Source: IPCC (2007)
Some are natural
some man-made
The Earth has natural systems that heat it and other natural systems that act as cooling factors. Thus an equilibrium is maintained.
But there is an imbalance being created and the factors that heat the Earth are becoming more prominent.
Atmospheric CO2 has increased from a pre-industrial concentration of about 280 ppmv to about 367 ppmv at present
Methane and nitrous oxide fare no better
To learn more about the concentration of GHGs in the atmosphere before the era of instruments and measurements, scientists are analyzing gases trapped in ice
And we find that…….
The concentrations of greenhouse gases that we are seeing now, has not been witnessed in the past
600000 years
Source: IPCC (2007)
We’re blanketing the Earth with more and more of these gases and the ‘ball is going warm’
Source: http://www.flickr.com/photos/perryham/3577638548/
14
13.2
14.8
Eleven of the last twelve years were the warmest since thermometer records began in 1850
A hot future awaits us
Global mean surface temperature could rise between 1 - 4.5 0C by 2100
What is increasing GHGs?
Forests are becoming croplands to feed our growing millions.
Fewer trees, more carbon dioxide in the atmosphere
Intensification of agriculture to feed the growing millions
Source: IGBP
Global fertilizer consumption
More nitrous oxide released
Source: http://maps.grida.no/go/graphic/the-richer-we-get-the-more-we-discard-human-consumption-waste-and-living-standards
Philippe Rekacewicz, UNEP/GRID-Arendal
Changing lifestyles
More methane generated by anaerobic decomposition of wastes in landfills
Changing lifestyles
http://www.flickr.com/photos/lingaraj/2415084235/
Increasing industrialization to meet our growing demands
Increased demand for electricity
From domestic consumersFrom industriesFrom the agriculture sector
Electricity generation
Source: International Energy Agency
0.82 kg of CO2 produced for every unit of electricity generated from coal.
That’s approx. 1 kg of CO2 produced for every unit of electricity we use.
Energy use
Source: CDIAC
What changes do scientists predict?
By the end of the century…
• Global mean surface temperature could increase by 1.0 to 4.5 0 C (best estimates)
• Global mean sea level could rise by 0.18 – 0.59 m
How will this affect our water resources
Precipitation patterns will change
There may be more intense rainfall on rainy days, resulting in floods
and more dry days in a year, causing drought
Damages due to floods has cost India
over Rs 800 crore every year
350 million Indians have been
affected badly due to drought in past ten years
Groundwater – it’s finite!
78% of assessed groundwater units in Delhi are over-exploited
(extraction > recharge)
India will reach a state of water stress before 2025
Sea level will be a minimum of 40 cm higher than today by
the end of 21st century
Source: TERI 1996
11 % of Bangladesh's coastal land is likely go underwater, creating 7 to 10 million climate refugees
What is the impact of a rise in sea levels?
Islands at low levels, such as Lakshadweep, can be flooded.Islands at low levels, such as Lakshadweep, can be flooded.
Entire ecosystems, such as the mangroves, can be wiped out.
Entire ecosystems, such as the mangroves, can be wiped out.
This image shows the change in pH of the oceans over the past 300 years. The brighter the color, the more the decrease in pH.
The solution is in our hands
We can do many things
• Electricity
• Water
• Green buildings
• Transport
• Renewable energy
• Afforestation
• Spread awareness
Acknowledgements
Ms Ulka KelkarMs Neha Rathi
