Chapter 2 Gateway 2

What is happening to

the Earth’s climate?

Global Climate Change

• The variation in global climate• Changes in the climatic patterns in the long

term• General trend has been an irregular but

significant increase in global temperature.

Global Warming• Process where

global temperatures increase over a long period of time.

Global Cooling

• Process where global temperature decrease over a long period of time.

Changes since 1880• Drastic fluctuations on annual basis.• 5-year mean still fluctuates.• Over 120 years, mean has risen significantly.• Increase in temperature is more obvious in

Africa, Parts of Asia and the Arctic.

Natural Causes of Climate Change

• There are some natural phenomena that will cause climate change.1. Variations in Solar Output2. Volcanic Eruptions

Variations in Solar Output

• Solar radiation changes as the magnetic field of the sun changes.

• Increase in magnetic activity will lead to increase in solar radiation.

• Sunspot activity leads to more solar radiation emitted.

• Solar activity cycle is linked with earth’s cycle of high and low global temperature. – High activity leads to spikes in temperature.

What are Sunspots?

Volcanic Eruptions

• During eruptions, cabon dioxide, water vapour, sulphur dioxide, dust and ash are released into the environment.

• Sulphur dioxide reacts with water to form sulphur-based particles in the atmosphere.

• These work with the dust and ash to reflect solar energy back into space, causing global dimming.

Global Dimming

• The gradual reduction in the amount of sunlight reaching the earth’s surface.

• Causes temporary cooling of the earth.• Eruption of Mt Pinatubo, 1991, lead to

lowering of temperatures in the northern hemisphere by as much as 0.6°C.

• Effect can last several years.

Greenhouse Effect

What is greenhouse effect?

• Process that sustains habitable temperature on earth.

• Shortwave radiation from the sun reaches earth as visible light.

• Longwave radiation is heat from the heated surface of the earth.– Earth’s surface is heated by the shortwave

radiation from the sun.

Process of greenhouse effect• Shortwave radiation comes from the sun.• Some of it is reflected and trapped in the

atmosphere by greenhouse gases.• Some of it passes through and heats up the earth’s

surface.• The earth’s heated surface emits (gives off) longwave

radiation.• Some longwave radiation is reflected back by the

atmosphere layer while some escapes.• The reflected radiation continues to heat up the

earth’s surface. • This maintains the optimal temperatures on earth for

life to exist.

What is enhanced greenhouse effect?

• When greenhouse gases in the atmosphere increase, the amount of radiation trapped increases.

• This causes the heat on Earth’s surface to increase.

• Key greenhouse gases are nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4).

Who causes this spike?Burning of Fossil Fuels• Industries and modern fossil-fuel burning

machines have accounted for the spike in greenhouse gases.

• Intense spike in all 3 tracked gases since 1500 to date (due to the onset of the Industrial Revolution and rapid human population growth)

Deforestation• Loss of forests due to removal and clearance

of tress.• Commercial value of timber• Enhance need for agricultural / residential /

commercial land• Loss of carbon lungs of the earth. • South America and Southeast Asia are the 2

highest areas of forest loss.

Reforestation

• Process where trees are planted to replace lost forest areas.

• China, India, Vietnam, USA has large scale reforestation programs.– When you need to reforest it means that you had

previously done deforestation.– Reforestation levels often fall short of deforestation

levels.– Reforestation also tends to be of lesser variety

compared to the original lost species.

Changing land use

Agriculture• Global increase in meat consumption leads to

increased livestocks reared.• Argentina is one of the world’s largest beef

producers.• Methane gas emitted from lifestock account for

30% of Argentina’s total greenhouse gas emissions.• Widespread use of machines in agriculture release

additional CO2 into the atmosphere.

Our new cow doesn’t release

any methane gas.

Industries

• Production of goods and services.• Secondary Industries are in manufacturing.– Conversion of fossil fuels.– Production of greenhouse gases as by-products

• Some processes or products have greater emissions.

• Carbon Dioxide emissions the key indicator of Industries.– Emerging economies contribute more due to rapid

emissions.

Urbanisation

• Process where more people live in urban areas.

• Widespread use of Fossil Fuels for energy.• High concentration of cars, buses and other

transportation.• Large emission of greenhouse gases.

Impact of Climate Change

• Changes in global climate impact humans.• Small temperature changes can lead to sea level

rising. • Melting of glacial and polar ice results in larger

volume of water in the sea.• Frequent extreme weather events and boom in

insects cause spread of disease.• In certain regions, growing season might

lenghten.

Sea Level Rise

• Increase in the mean height of the sea’s surface.

• High negative impact to humans living near coastal areas.

• 2/3 of the world’s largest cities located in coastal areas are at risk due to rising sea level.

• Island nations are especially at risk.

More Frequent Extreme Weather

• Extreme weather event is a severe and rare weather phenomenon that leads to significant economic losses and loss of lives.

• Extreme weather events have increased in the past decades.

• Rise in surface temperatures lead to disruption of the hydrological cycle.

• Increase in water vapour and latent heat causes a warmer atmosphere.

• Warmer atmosphere conducive to extreme weather events.

• Super tornadoes; Massive droughts.

Spread of infectious insect-borne diseases

• Climate change leads to increase temperatures and rainfall in some areas.

• Insects thrive in these conditions.• Insect-borne diseases will spike.–Malaria and Dengue are spread by

mosquitoes that increase due to higher rainfall, leading to more stagnant water gathering.–Warming up of temperate areas also lead

to change in disease profiles.

Lengthening the growing season

• In certain areas, rise in temperature brings benefits.• Previously cold periods stay warmer. • Growing season is extended as a

result.• Good for crops that require higher

temperatures

Shortening of growing season

• Temperate crops• Require cool climate to grow effectively. • Rise in temperature leads to shortening

of growing season.• Apples, Cherries, Strawberries.

http://www.youtube.com/watch?v=oJAbATJCugs

Responses to Climate Change

• International Level Responses– Kyoto Protocol– Copenhagen Conference

• National Level Responses– Singapore Green Plan– Green Mark Scheme Singapore– Energy Labelling Programme India– The Indian Network of Climate Change

Assessment (INCCA)

International ResponsesKyoto Protocol 1997

• Agreement to reduce greenhouse gases emission levels

• Developed countries had greater responsibility on reducing greenhouse gas

• Not all nations in the United Nations signed the protocol.

Kyoto Protocol Successes

• Many countries met targets set–Greece, Finland, Ireland, etc

• Successfully encouraged the development of sustainable development

• Countries earned carbon credits by helping developing countries develop sustainably.

Kyoto Protocol Limitations

• Not all countries met targets.• No compulsion to help developing

countries develop sustainably.• Countries that did not sign continue

to contribute significantly to global emissions.

Home / BYOD Task

• Go online and search for the following information.1. What is the difference between countries

signing the Kyoto protocol and those that ratified it?

2. Which country(s) have not signed the protocol and which ones have not ratified it?

• Complete the handout and submit it the next lesson.

Copenhagen Conference 2009

• Discussion of issue of climate change coping measures by important political figures.

• Copenhagen Accord drafted.• Long-term goal of keeping increases in

global mean maximum temperature to within 2°C of global temperatures before 1850.

Copenhagen Accord Success

• Successfully setting of targets for greenhouse gas emissions

• Developed countries committed to reduction by 2020.

• Provision of US$30Billion to aid LDCs between 2010-2012.

• Long term aid of US$100Billion a year by 2020.

Copenhagen Accord Limitations

• Greenhouse gas reduction targets unable to create the desired temperature reduction.

• No concrete plans on how to reduce greenhouse gas emissions.

• Many Developed countries refused to sign.

• Targets are taken as guidelines, many countries do not adhere.

Why is it so difficult to get countries to adhere to the

Copenhagen Accord?

What could be more important than the

Earth?

National Level Responses

• Policies that individual countries implement.

• Work towards the international goal of reducing greenhouse gas emissions.

• Each country has different economies and issues so their national level responses will be different.

Singapore1. Singapore Green Plan 20122. Green Mark Scheme3. Plant-A-Tree programme4. National Urban Transport Policy

(NUTP)

Pg 115- 116

1. Energy Labelling Programme2. The Indian Network of Climate

Change Assessment (INCCA)

India Pg 117

Possible Question

“Explain with the aid of examples you have studied, why national level responses to climate change are important and how they may or may not be effective.” [8m]

How to answer?

• 1m for the difference between International and National level responses.

• 1m for purpose of National Level response• 1m for Describing the 1st example.• 1m for the Successes of 1st example• 1m for the Limitations of 1st example• 1m for Describing the 2nd example.• 1m for the Successes of 2nd example• 1m for the Limitations of 2nd example

10 minsTry it!

Use the info in your

textbook

Homework

• Complete Qn 7 and 8 (a,b &c) of Checkpoint Pg 118.

• Write your answers on foolscap paper and submit at the end of the next lesson.