BY MEDIDA SUNIL KUMAR

Evidences of Climate Change and Drought

What is mean by climate?

What is mean by climate change?

What is mean by climatic variability?

Past Climate of Earth

1. Earliest Atmosphere:

Primarily H2, water vapor, CH4 and  NH4 like Jupiter and Saturn.

2. Second Atmosphere:

Consisting largely of N2 plus CO2 and inert gases, was produced by volcanism

Early Sun put out 30% lower solar radiance associated one cold glacial phase about 2.4

billion years ago

Late Archaean eon O2 containing atmosphere began to develop, apparently produced by

photosynthesizing cyanobacteria

3. Third Atmosphere:

 Movement of plate tectonics and volcanism released CO2

Free oxygen did not exist in the atmosphere until about 2.4 billion years ago

The amount of oxygen in the atmosphere has fluctuated over the last 600 million years,

significantly higher than today's 21%.

Evolution of Earth’s Atmosphere

Causes of Climate Change

Natural Causes

Volcanoes

Solar Output

Earth's Orbit around the Sun

Anthropogenic Causes

Fossil Fuels

Industrial Revolution

Change in Land use

Solar activity vs temperature

Greenhouse GasPre-1750

Tropospheric Concentration

Recent Tropospheric

Concentration

Change in Tropospheric

Concentration

Carbon dioxide (CO2) 280 ppm 400 ppm 40%

Methane (CH4) 700 ppb 1874 ppb 168%

Nitrous oxide (N2O) 270 ppb 324 ppb 20%

Chlorofluorocarbons (CFCs)

0 21-529 ppb NA

Ozone (O3) 25 ppb 34 ppb 36%

We Have Also Altered the Atmosphere

Evidence of Changing Climate Evaporation & rainfall are increasing

Coastal glaciers are retreating

Mountain glaciers are disappearing

Permafrost is thawing

Sea ice is shrinking

Greenland is melting

Sea level is rising

Species are moving

Evaporation & Precipitation are increasing

NCDC, 2000

Effect is not uniform; most places getting wetter, some getting drier.

Muir Glacier, Alaska, 1941-2004

NSIDC/WDC for Glaciology, Boulder, compiler. 2002, updated 2006. Online glacier photograph database. Boulder, CO: National Snow and Ice Data Center.

August 1941 August 2004

Coastal Glaciers Retreating

Glacier Retreating

1875 2004

Courtesy Lonnie Thompson

Mountain glaciers are disappearing

Permafrost melts when T ≥ 0°C ACIA 2004

Permafrost is ThawingAverage annual ground temperature, Fairbanks, AK

°C

                           

NASA photograph

North Polar ice cap is sea ice -- it’s floating and so does not change sea level when it melts.

But the reduced reflectivity when the ice is replaced by water amplifies the warming effect of greenhouse gases.

Arctic Summer Ice is Shrinking

1979 2003

Greenland is melting

ACIA, 2004

Summer surface melting on Greenland, 1979-2002

Greenland melting (continued)

2005 broke the 2002 record

Sea Level

Data source: Coastal tide gauge records. Credit: CSIRO. 2012. Data source: Satellite sea level observations. Credit: CLS/Cnes/Legos. 2012

Sea-level from satellites: 4 cm rise in last 10 years

Rise in global ocean heat content 1955-2005

Some ups and downs, but clear overall increaseLevitus et al., 2005, GRL

Extreme weather events

Image Credit: http://www.grida.no/graphic.aspx?f=series/et-common/trends_L.gif

Global surface temperature 1855-2010

Observed surface temperature trend

Trends significant at the 5% level indicated with a ‘+’. Grey: insufficient data

Vulnerability of India to Climate Change

WHAT WILL HAPPEN IN THE CASE SEA LEVEL RISE ??

DROUGHT

Drought is one of the most widespread complex and complicated

disasters.

Extended period of deficient rainfall relative to normal's

68% of the country’s geographical area is prone to drought in varying

degrees

Chronically drought prone areas: – @ 33% (RF: <750 mm)

Drought prone area: – @ 35% (750-1125 mm)

Drought onset: Total rainfall deficiency is > 10 percent of normal's

Severe drought: Total rainfall deficiency is > 25 percent of normal‘s

Period No Region affected by famines/droughts

5th century BC 1 Kashmir , Ayodhya (eastern UP), Rajasthan, Gujarat,Maharashtra & Punjab

1st century BC 1 Kashmir9th century AD 1 Kashmir10th century AD 2 Kashmir , Punjab, large parts of northern India11th century AD 2 Delhi, Bihar , Bengal, Orissa, Rajasthan & Kashmir13th century AD 4 Orissa, Bihar , Assam, Bengal, Rajasthan, Maharashtra & Gujarat14th century AD 5 Delhi, Rajasthan, Maharashtra, Mysore, Karnataka & Gujarat 15th century AD 5 Rajasthan, Maharashtra, Orissa, Assam & most parts of India,

especially the areas along the rivers Ganga & Yamuna16th century AD 6 Most of the then Bombay presidency, Punjab, Maharashtra, Delhi,

Rajasthan, Kutch & central India17th century AD 6 Gujarat, Maharashtra, Rajasthan & Bengal18th century AD 24 Bombay presidency , Gujarat, Maharashtra & Madras19th century AD 38 Rajasthan, Gujarat, Orissa, Maharashtra, Andhra Pradesh,

Kashmir , Himachal Pradesh & Bihar 20th century AD 60 Rajasthan, Gujarat, Orissa, Andhra Pradesh, Kashmir, Himachal

Pradesh, Bihar , Maharashtra, Jammu &KashmirSource ‘Drought of Relief’, Down to Earth, May 2001

Chronology of drought and famine in India

Typical Effects of drought Failure or loss of crops.

Loss of dairy and fishery production.

Reduced energy production.

Increased unemployment

Soil erosion.

Acute shortage of drinking water.

Health hazards and loss of life.

Widespread poverty.

Prices of all commodity shoot up.

Strategies adopted before drought at household level

• Crop diversification on/ crop variety diversification

• Livelihood diversification

• Staggering of seedling periods

• Early migration

• Keeping land fallow

• Limited re-sowing

Early warning and response mechanisms

Close monitoring of drought

Augmentation of water supply and conservation

Proper and scientific expansion of irrigation facilities

Land use

Inter-basin transfer of river waters

Promoting Water-shed programmes

Main mitigation strategies