Climate change and Water resources

Changes are being seen around the world

Upsala glacier, Patagonia Source: Greenpeace

Pederson Glacier (Alaska)

Larsen B ice shelf, West Antarctica Source: NASA 3250 square km of ice 220 m thick broke off

Sea levels are rising Source:

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 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 CO 2 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 years Source: IPCC (2007)

We’re blanketing the Earth with more and more of these gases and the ‘ball is going warm’ Source:

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 C 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: Philippe Rekacewicz, UNEP/GRID-Arendal Changing lifestyles More methane generated by anaerobic decomposition of wastes in landfills

Changing lifestyles

Increasing industrialization to meet our growing demands

Increased demand for electricity From domestic consumers From industries From the agriculture sector

Electricity generation Source: International Energy Agency 0.82 kg of CO 2 produced for every unit of electricity generated from coal. That’s approx. 1 kg of CO 2 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 C (best estimates) Global mean sea level could rise by 0.18 – 0.59 m

How will this affect our water resources

In the short term, the increased melting of glaciers can cause floods. In the long term, these glaciers will disappear, causing rivers to dry up and droughts to occur.

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

The scarcity of water has given rise to many conflicts between nations and states. This can lead to rioting, causing… Loss of life Loss to public goods Loss to the economy

Sea level will be a minimum of 40 cm higher than today by the end of 21st century Source: TERI % 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. Entire ecosystems, such as the mangroves, can be wiped out.

Burning fossil fuels, among other activities, raise the level of carbon dioxide in the atmosphere. This carbon dioxide dissolves in the oceans and decreases the pH of the oceans.) Many species can survive in only a narrow band of pH levels, they may become extinct. 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 Kelkar Ms Neha Rathi