FACTORS AFFECTING CLIMATE CHANGEBy: Aiman and Vaishnavi

WHAT IS CLIMATE CHANGE?

Change in average ‘weather’ Everything

associated to weather

Temperature Precipitation

Referred to on a global scale

NATURAL CAUSES

Solar output Ocean variability Continental drift Earth’s tilt Comets, meteorites Orbital modifications Volcano (dust and gas) Less snow and ice cover on

Earth

VOLCANOES

Large volumes of sulphur dioxide, water vapour, dust, ash in the atmosphere

Over the years: sulphur dioxide can reach higher levels of atmosphere Block sun rays leads to

cooling Sulphur dioxide combines

with water Forms droplets of sulphuric

acid Small droplets can stay in air

for several years

EARTH’S TILT

Causes seasons Controls severity of the

seasons More tilt = warmer

summers and cooler winters

Less tilt = cooler summers and milder winters

Earth’s axis not fixed Changes approx. half a

degree a century Causes changes in climate

OCEAN CURRENTS

Oceans cover approx. 71% of the Earth Absorb twice as much of sun’s radiation than

land Move a lot of heat across the planet Can change direction and slow down Escaped heat usually in the form of water

vapour (most abundant greenhouse gas) Forms on clouds shading the Earth’s surface

Has a cooling effect

CO

NTIN

EN

TAL

DR

IFT

•NEW ICE SHEETS•NEW VOLCANOES•NEW OCEANS

ANTHROPIC CAUSES

Increase in fossil fuel use (Industrial Revolution) Natural resources overused

(construction, industries, transport, consumption)

Clearing of land for houses Increases in dust and smog Changes in land use Increase in C02 emissions

and other green house gases Changes since industrial era

30% increase in C02

145% increase in CH4

15% increase in N20

GREENHOUSE EFFECT

Natural system regulates Earth’s temperature

When sun rays hit Earth’s atmosphere, some reflected, others absorbed and later radiated into atmosphere

Some heat radiated to atmosphere does not escape to space Absorbed and trapped by atmospheric

gases (GHG’s)

Certain human activities disrupt balance of the system

More heat trapped in the atmosphere increase in Earth’s temperature

GREENHOUSE GASES

Produced by combustion of fossil fuels Energy-production Transportation Industry

Study of carbon flow through carbon cycle ½ of human-produced

C02 in atmosphere

ANTHROPOGENIC SOURCES OF GREENHOUSE GASES

CO2 (Carbon Dioxide) Methane (CH4) Nitrous Oxide (N2O) Chlorofluorocarbons (CFCs)

CARBON DIOXIDE

Most important Burning of fossil fuels Uses of fossil fuels

Energy in transportation & manufacturing

Heating Electricity generation Industry

Rising emissions of C02 due to Land use Deforestation Land clearing agriculture

METHANE

Sources Rice farming Cattle ranching Decaying organic materials Sewage treatment plants Coal mining Natural gas extraction Deforestation

Slow smouldering of trees combustion reaction Released from landfills, waste dumps, oil drilling,

coal mining

NITROUS OXIDE

2/3 comes from management of livestock feed and waste

Nitrogen fertilizer usage Certain industrial

processes Fossil fuel use Emission partly from

fertilizers , leguminous plants such as beans and pulses

nitrogen to the soil.

CHLOROFLUOROCARBONS

Refrigerator agents Atmospheric levels

now decreasing due to international treaties Montreal Protocol on

Substances that Deplete the Ozone Layer

Sources of Greenhouse Gases in Canada

Sources of Greenhouse Gases in Agriculture

Bibliography

http://www.ccse-swcc.nb.ca/climat/CCAF/PEISCIA.pdf http://www.tutorvista.com/ks/factors-affecting-climate-chan

ge http://web.viu.ca/sc403/Global_Warming/page3.htm