Unit19: Global Warming

By : An Jiasheng (23) Andrew Lam (24) Chong Kai Xiang (26) Class: 203

What is global Warming?

Due to recent human activities , there is an increase in air pollutants in our atmosphere.

These air pollutants are keeping excess heat within the earth’s atmosphere.

These “enhanced Green house effect” caused by pollutants traps more infra-red radiation and cause Earth’s climate to heat up.

Extent of global warming

Global Warming affects the whole world.

Example ,due to global warming ,mean surface area of the world went up. Most places in the world have higher temperature than usual.

Causes of global warming

Greenhouse gases present in the atmosphere.Methane(CH4) Nitrous Oxide(N2O)Carbon Dioxide(CO2)Chlorofluorocarbons(CFCs)

Methane(10% of greenhouse gases in atmosphere)

Natural by-product of bacterial actions in the stomach of livestock and in the water of rice field.

In keeping with the effort to increase food supply, more methane will be released into the air.

Nitrous oxide (5% of greenhouse gases in atmosphere)

Emitted through burning of fuels and use of chemical fertilizers containing nitrogen.

Carbon dioxide (72% of the greenhouse gases in atmosphere.

Released when any form of burning takes place.

Burning of fossil fuels and large-scale destruction of forests (deforestation)are main cause of increase of carbon dioxide.

CFCs(13% of the greenhouse gases in atmosphere

Man-made chemicals used in manufacturing of aerosols, air-con and refrigerator.

Consequences of global warming (the Environment)

Scientists predict that average world temperature will rise by 0.5 Celsius every 10 years over the next 100 years. After the increase of more than 6 degrees, we shall die.

Due to increase in evaporation More rain will likely to fall in tropical

regions Temperate regions will experience

longer and drier summer, shorter and wetter winter.

There will be more droughts in the interior of north America and Russia and more storms in Asia.

Environment

Polar ice caps and glaciers will melt and shrink.

This may cause … Sea level to rise by 3

meters Low-lying regions will be

flooded There will be more storms

and land slides and increased river flooding.

Effects of climate change

In tropical regions where floods or droughts are expected, crop yields will decline.

Present arable lands in temperate regions will also suffer due to a longer and drier summer season.

However, present dry places will experience more rain causing their yields to increase.

Effects of sea level changes by the year 2050

Islands in South Pacific Ocean could be submerged

Settlements, port facilities and coastal structure might be damaged

Countries like Venice and London will sink.

Water supply to coastal settlements will be affected when salt water seeps into groundwater due to flooding making the water to saline.

River Delta will be flooded, affecting people living there.

Wildlife in salt marshes and coral reefs will be threatened.

Mangrove swamps with its species will be destroyed.

Measures to reduce the impact of global warming

Reduce CO2 emission On the world scale

Earth summit 1992, 154 countries pledge to stabilize emission by 2000

On the country scale Impose carbon tax Introduce energy substitutes like

solar energy. Retain trees to absorb carbon

dioxide Introduce measures to save

electricity Individual scale

Switch off electric appliances when not in use.

Continue …

Reduce nitrous oxide emission World scale

NIL

Country scale Improve public transport Reduce use of chemical

fertilizer containing nitrogen

Individual scale Use public transport rather

than private owned transport.

Continue…

Reduce methane emission World scale

Stop cows from farting. Reduces 10kg of methane every year

Country scale Reduce demand for meat &

rice product. Individual scale

Find food substitutes for meat and rice.

Continue…

Reduce CFCs emission World scale

Montreal Protocol signed by 92 countries in 1992.

Country scale Ban the use of CFCs

Individual scale Buy only non-CFC products

Adjusting to the effect of global warming

Rising sea level Country scale

Limit the no. of buildings built along the coast.

Provide coastal protection such as dykes.

Individual scale Develop right attitude and help

reduce any form of heat increase to the atmosphere.

Switch off any unused fans or lights.

Reduce comforts of energy consuming appliances like dishwasher and air-con.

Continue..

More frequent drought conditions Country scale

Initiate research to produce new crops which can grew in dry conditions.

Introduce efficient irrigation system

Individual scale Adopt right attitude towards

using water Consciously save water

Continue….

Extinction of wildlife and plant species Country scale

expand and create wildlife reserves

Create a global network of corridors of natural vegetation to allow for free movement of species.

Individual scale Aware of ecological problems and

solutions Respect natural habitat Decision makers and profit making

developers should conserve rather than recreate.

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