Global warming and Climate change

Prepared by: Veereshgouda. M. Police Patil

Contents

• What is global warming?• Science behind Global Climate Change • Green house effect• GHG’s concentration • Present and future trends in Global Climate Change • Sources of Green House Gases • Trends in Co2 emission • Consequences of global climate change: World and India

What is global warming?

Global warming: Regular increase in

mean annual temperature of the

earth.

This is mainly because of increase in

concentration of GHGs in the

atmosphere (especially CO2)

78% nitrogen

20.6% oxygen

< 1% argon

0.4% water vapor

0.036% carbon dioxide

traces gases:Ne, He, Kr, H, O3

Methane, Nitrous Oxide

Science behind global warming Green house effect

The green house gases - CO2 , methane, N2O, CFC, SF6, O3 (3-7%)

etc., absorb less of the insolation in atmosphere and much of the outgoing long wave radiations. Thus, they retain the heat in the atmosphere.

Results in

Uncomfortness

Diseases and deaths (Cancer, skin diseases etc)

The Green house gases (GHGs) provide a blanketing effect in the lower strata of the earth’s atmosphere, and this blanketing effect is being enhanced because of the human activities like burning of fossil fuels etc.

Greenhouse Effect & Global Warming

• The “greenhouse effect” & global warming are not the same thing. – Global warming refers to a rise in the temperature of the

surface of the earth. • An increase in the concentration of greenhouse gases leads to

an increase in the the magnitude of the greenhouse effect. (Called enhanced greenhouse effect) – This results in global warming.

Green House Gas Inventory

Carbon di-oxideCO2

Methane – CF4 Nitrous Oxide – N20

Perfluoromethane –CF4

Sulphur Hexafluoride – SF6

HCFC

CFC - 12

Emission trend of global green house gases

(www.unfccc.int)

Global warming potentials (GWP ) of Green House Gases

The main greenhouse gasesGreen house

gasesChemical formula

Pre-industrical

concentration

Conc. in 1994

Atm. life time

(years)

GWP

Carbon-dioxide

CO2 278000 ppb 358000 ppb Variable(Apprx.500)

1

Methane CH4 700 ppb 1721 ppb 12,2 +/- 3 21

Nitrous oxide N2O 275 ppb 311 ppb 120 310

CFC-12 CCL2F2 0 0503 ppb 102 6200- 7100

HCFC-22 CHCLF2 0 0105 ppb 121 1300 –1400

Tetrachlorofluoromethane

CF4 0 0070 ppb 50000 6500

Hexafluoride SF6 0 0032 ppb 32000 23900

UNITED NATIONS ENVIRONMENT PROGRAMME

320 ppb380

ppm

1775 ppb

520 ppb

250 ppb

GHG’s concentration in atmosphere

Global Carbon Dioxide (CO2) emissions from fossil-fuels 1900-2008

Global carbon emissions from fossil fuels have significantly increased since 1900. Emissions increased by over 16 times between 1900 and 2008 and by about 1.5 times between 1990 and 2008.

Sl. No.

GHG Concentration Remark

1 Atm. CO2 390.5 ppm 40% greater than in 1750.

2 Atm. nitrous oxide (N2O) 324.2 ppb increased by 20% since 1750.

3 Atm. methane (CH4) 1803.2 ppb 150% greater than before 1750.

4 Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6)

------ increased relatively rapidly but their contributions to radiative forcing are less than 1% of the total by well-mixed GHGs

Present status of Direct GHG’s concentration (2011)

IPCC Assessment report 2013

Anthropogenic sources for GHG’s emissionGreenhouse gases Anthropogenic sources

Carbon-dioxide Fossil fuel combustionLand use conversion Cement production

Methane Fossil fuelsRice paddiesWaste dumps

Livestock

Nitrous oxide Fertiliser industrial processes combustion

CFC-12 Liquid coolants, FoamsHCFC-22 Liquid coolantsTetrachlorofluoromethane Production of aluminiumHexafluoride Dielectric fluid

Fossil fuel combustion Cement production

Land use conversion

Paddy field

Waste dumps

Livestock

Vehicular carbon emission

Global Greenhouse Gas Emissions by Source

1st

2nd

Land use change &

(www.unfccc.int)

Emission trend of global green house gases along regions

Highest carbon emitter(@ 1600 m MT of C/yr)

5th place, emits (@ 700 m MT of ‘C’/yr)

(www.unfccc.int)

2008 Global CO2 Emissions from Fossil Fuel Combustion and some Industrial Processes of top countries

Consequences of global warming

• Melting of polar region• Rise of sea level• Effect on agriculture• Human and animal Health

Impact of Global Warming on India• Unseasonal rains• Increasing Water Scarcity• Lower Wheat Yields• Increased incidence of heat waves• Shrinking of Himalayan Glaciers

Consequences…

Effect on natureEffect on societyEffect on glaciers Effect on agriculture and faunaEffect on forests

Consequences …

Effect on nature

In India 5 to 25% decline in winter rain fall, leading to

droughts during dry summer months

Increase in average summer monsoon rainfall over the

Indian subcontinent is only 10 to 15 per cent.

(Singh and Sonatakke,

2002)

Death of animals due to scarcity of water

Consequences contd…

Effect on society

Collapse of Maya civilization, (around 3000 years ago) on

Meso-America due to climate deterioration.

(Webster, 2002)

Collapse of Subir, (Around 300 AD agriculture civilization) of

Northern Mesopotamia in Syria.

(Weiss,

1993)

Consequences contd…

Indian Scenario

Almost all 335 glaciers in the Sutlej, Beas and Spiti river basins of Himachal pradesh are receding because of global warming.

(Sharma, 2001)

Overall prediction

By 2050, sea level throughout the world will rise by 21 cm.

(Anon, 1999)

Sea will rise by 18 cm in the year 2020 and 58 cm by the year 2090.

( Kumar, 2002)

Effect on glaciers

•Scary pictures of the northern polar regions in 1979 & 2005

•Polar ice has been decreasing by 1% per year since 1979.

1979 2005

Polar bear in struggle

Effect on Agriculture

Indian Scenario

At 0.5 o C increase in mean

temperature in Punjab,

Haryana and Uttar Pradesh

there would be a reduction in

productivity of wheat crop

by 10%.

(Samara and Sharma, 2002)

Overall prediction Decline in yield of crop in

Latin America, from Mexico to Argentina.

Predicted effects of climate change on agriculture by 2050

Climatic element Expected changes by 2050’s

Effects on agriculture

CO2 Increase from 360 ppm to 450 - 600 ppm

Good for crops: increased photosynthesis; reduced water use

Sea level rise Increased in south and offset in north by natural subsistence/rebound

Loss of land, coastal erosion, flooding, salinisation of groundwater

Temperature Rise by 1-2oC. Winters warming more than summers. Increased frequency of heat waves

Faster, shorter, earlier growing seasons, range moving north and to higher altitudes, heat stress risk, increased evapotranspiration

Precipitation Seasonal changes by ± 10% Impacts on drought risk' soil workability, water logging irrigation supply, transpiration

Storminess Increased wind speeds, especially in north. More intense rainfall events.

Lodging, soil erosion, reduced infiltration of rainfall

Source: Climate change and Agriculture, MAFF (2000)

Possible benefits and drawbacks of global warming on agriculture, based on an illustration in Scientific American, March, 1994

Consequences contd…

Indian Scenario

The Bengal tiger could

vanish

Effect on Fauna

Overall prediction

Central American Quetzal bird could disappear.

Other animals that could vanish around the world are Polar Bear, Penguins and the central African Mountain Gorilla.

(Anon, 2001)

Effect on fauna contd…

Polar bear

Penguin

Bengal tiger

American Quetzal bird African Mountain Gorilla

Consequences contd…

Effect on forests

Shift of species: 1oC rise in temperature will displace the limits

of tolerance of land species some 125 km towards the pole

or 150 m vertically on mountains.

(Anon, 1999)

Consequences contd…

Effect on insect-pest incidence:

Increase in temperature leads to:

• Accelerate to breeding population of insects resulting in more

generation per year

(Hedden, 1987)

Impacts of global warming on climate of India

• India is already a disaster prone area, with the statistics of 27 out of 35 states and Union territories being disaster prone, with most disasters being water related.

• According to surveys, in the year 2007-2008, India ranked the third highest in the world regarding the number of significant disasters, with 18 such events in one year, resulting in the death of 1103 people due to these catastrophes.

Catastrophes of climate change in India

• Floods• Droughts• Cyclones• Effects on the sea and coastal areas

Floods in India

• Approximately 40 million hectares of the land is vulnerable to floods, with 8 million hectares affected by it.

• A temperature increase of 2 °C in India is projected to displace seven million people, with a submersion of the major cities of India like Mumbai and Chennai.

Droughts

• 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.

• The World Record Of Drought Was In 2000 in Rajasthan, India.

Cyclones

• As a result of global warming, the average number of hurricanes per year has increased over the past 30 years.

• The notable cyclones in Indian history include the 1737 Calcutta cyclone and 1970 Bhola cyclone, which affected more than a million people.

Effects on the sea and coastal areas

• A one meter sea level rise is projected to displace approximately 7.1 million people in India and about 5,764 Km2 of land area will be lost, along with 4200 Km of road.

• The effects of global warming have also caused damage to coastal infrastructure, aquaculture and coastal tourism. The aquatic ecosystems such as mangroves, coral reefs and grass lands have also been affected by the climatic change.