Global Warming & Climate Change

Global Warming & Climate Change

On line Taster Course

Welcome

Welcome to the Global Warming & Climate Change on line taster course!  This is an opportunity for you to  learn in your own time, at your own pace, and in the comfort of your own home. 

In this taster you will :

·   learn what we mean by global warming & climate change

·   read short extracts and watch short videos on causes and explanations of global warming & climate change

·   reflect on the impact of global warming and climate change

We hope you enjoy the course!


Don't forget when you get to the bottom of the page, click on the 'Older Posts' link to get to the next section.

Activity 1

We regularly see and hear the terms global warming and climate change on TV, the Internet and in the newspapers. Think about what those words mean to you, and jot down your definition of global warming and climate change here:

Answers

Answer:

Global warming refers to the phenomenon of the Earth becoming hotter.  This has been a topic of much interest and debate in recent years, both amongst scientists and within the general population. Scientists now agree that global warming is a reality. However, there is still a debate on the causes of this warming. Some have argued that changes in the Earth’s temperatures are normal and part of a pattern of the Earth having cooler and hotter cycles during its long history, but a growing number  of scientists now believe that human activity over the past 200 years has had a big effect on the Earth’s temperature.

Climate Change refers to the recent disruptions to the world’s climate -  new patterns of heat and cold, floods and droughts, for example. This is not about weather: weather describes local conditions of snow, rain, wind etc, and that, of course, can be very changeable. The fact that the UK has had two severe winters in a row with heavy snowfall does not mean that the British climate has changed. Neither does the fact that we get the occasional extremely hot summer, with temperatures over 30 degrees. These are localised weather conditions. However, if long freezing winters or  Mediterranean summers continue and become the norm over decades, then we might indeed be experiencing climate change.

Activity 2

 Look at the statements below. Do you agree or disagree with them? Or are you unsure? There are not always clear rights or wrongs, and this is still an area where there is a lot of debate with few clear cut answers.

Global warming is bad for places like Africa, but in the UK we’ll have better weather

Global warming has got nothing to do with carbon dioxide emissions

There’s nothing we can do to stop global warming

Answers

Answers:

Global warming is bad for places like Africa, but in the UK we’ll have better weather.

Scientists believe that areas that are already dry and prone to drought - like certain regions of Africa -  will get even hotter and dryer  as a result of global warming,  but it does not necessarily follow that places like the UK will get warmer.  As the Earth’s temperature rises, the polar ice caps start to melt, and the icy water flows into the oceans. As the oceans get colder (due to the ice water from the melted ice caps), the ocean currents may change.  For example, the  reason we have a mild climate in the UK is due to the Gulf Stream - a current that brings warm water from the tropics up to Britain.  But, if the oceans get colder, it is possible that the Gulf Stream will no longer bring warm water up to Britain, and we could have a climate more like Canada or Moscow, with long, freezing winters, with temperatures of  40 degrees below zero.  However, the reality is that no one knows exactly what the impact of a warmer planet will be.

Global warming has got nothing to do with carbon dioxide emissions

First of all, Carbon dioxide in the atmosphere is not bad: in fact we couldn't live without it! Carbon Dioxide is one of the gases in the atmosphere which trap the sun’s energy and keep the surface of the Earth warm ( known as the Greenhouse effect).  Without these gases to trap the sun’s energy, the heat from the sun would go back into space and the planet would be permanently frozen.  

Most accept that carbon dioxide levels in the atmosphere have risen  dramatically  since the Industrial Revolution, but how far global warming is linked to that increase is still a matter of debate.  Some believe that changes in global temperatures happen in cycles and are a natural phenomenon.  However, there is a growing consensus amongst scientists that the high carbon dioxide emissions over the past two centuries have led to a greater warming of the Earth’s surface than would have occurred naturally.

There’s nothing we can do to stop global warming

Global warming is already happening, so it is too late to think about stopping it altogether.  However,  some  scientists think that although the situation is  serious,  we can still make a difference to global warming, and stop it becoming worse - but only if all the countries in the world are prepared to take action, and reduce carbon dioxide emissions as a matter of urgency.  This is why the conference in Copenhagen in December 2009 was considered so important.  Unfortunately, the conference ended without any agreements, leaving scientists and others concerned about climate change in despair.

Activity 3

Watch the short video Science behind the Climate.  It explains a little more about greenhouse gases, ocean currents etc. Click on the link below:  

http://news.bbc.co.uk/weather/hi/climate/newsid_8338000/8338909.stm

Activity 4

Carbon Dioxide

Carbon dioxide keeps cropping up whenever we discuss global warming and climate change – so what role does it play, and why has it become such an issue?

What role does Carbon Dioxide play?  

Respiration:

All living things need oxygen to survive. They take in oxygen, use it to keep themselves alive, then release carbon dioxide into the atmosphere as a by product. This process is called respiration.  For example, we breathe in ( or take in)  oxygen from the atmosphere and when we breathe out, we release carbon dioxide in our breath.

Photosynthesis:

Plants, in addition to using carbon dioxide as part of respiration, also use it in another process.  Plants cannot move and gather or hunt for food, so they have developed an ingenious process called photosynthesis which enables them to create food from carbon dioxide. They take in carbon dioxide from the atmosphere or the soil, transform it into food,  then release oxygen into the air as a by product.

See the diagrams below

This efficient recycling of oxygen and carbon dioxide is key to life on Earth and ensures that the planet and its living organisms never run out of oxygen or carbon dioxide.  Carbon dioxide is made up of 1 part  carbon and 2 parts oxygen.  Carbon and oxygen are two chemicals that are necessary for life on Earth – and  they have both been around on the planet since life on Earth began.  An important fact about these chemicals is that there is the same amount of oxygen and carbon on Earth now as there was millions of years ago.  This means that these chemicals are recycled over and over again.

 

Carbon storage.   While much of the carbon dioxide  is in the atmosphere, to be used in processes of photosynthesis and respiration, a great deal is stored in rocks, the soil and the oceans. For example, when plants or animals die much of the carbon goes into the soil where it is stored, or in the case of sea animals the carbon goes into the ocean.

This stored carbon dioxide is slowly released into the atmosphere, for example, rocks gradually get worn away and the carbon dioxide then escapes into the atmosphere, or the carbon dioxide in sea water gradually travels to the surface and into the atmosphere. This is a cycle which is more or less in balance : the total amount going into store is roughly the same as the amount being released.

Balance  This balancing act – the carbon cycle - ensures that the overall levels of carbon dioxide in the atmosphere are kept more or less constant. And up until about 200 years ago, this balancing act worked.  However, since the Industrial Revolution we have been using fossil fuels – coal, oil  and gas - for manufacturing ( factories ), heat ( e.g. central heating ) and electricity ( e.g. power stations). And that has upset the balance.

Fossil Fuels:  Coal, oil and gas all release large amounts of carbon dioxide into the atmosphere when they are burned. Burning fossil fuels releases about 20 time more carbon into the atmosphere than would occur naturally. So where does all that extra carbon dioxide go?  The answer is in the atmosphere.   In the past the oceans stored all the excess carbon dioxide as part of the carbon cycle, but now so much carbon dioxide is being released as a result of the burning of fossil fuels that the oceans cannot absorb it. The gas now just builds up in the atmosphere.

Why is this an issue?   You read earlier in Activity 3 that carbon dioxide is one of the Greenhouse gases, and that it has the important function of keeping the Earth warm. However,  like so much in Nature, this is about balance: the right amount of carbon dioxide ensures that we trap a certain amount of the sun’s heat - sufficient to keep the surface of the Earth warm enough for life to survive. The more carbon dioxide in the atmosphere, the greater the Greenhouse effect, and the warmer the surface of the Earth. 

While there is still some debate on the exact impact higher temperatures could have on life on Earth, there is nevertheless a consensus that even a couple of degrees difference could have quite devastating consequences.

Questions:

1. What happens during respiration?
2. What is photosynthesis?
3. Some carbon dioxide is in the atmosphere but much of it is stored. Where?
4. What are fossil fuels?
5. How has the burning of fossil fuels created a problem?

Activity 5

  There  now seems little doubt that the Earth is getting warmer  – but how do we know whether this is a natural phenomenon or  whether  human activity is to blame ?

Click on the link below to see this short video:  David Attenborough: The Truth about Climate Change

http://www.youtube.com/watch?v=S9ob9WdbXx0

Activity 6

There’s been a lot to take in the first 5 activities! Before moving on, let’s recap on what’s been covered so far:

·         Global warming is a reality. How far this is due to human activity is subject to debate

·         There is a growing consensus that humans have contributed to global warming through high levels of carbon dioxide emissions in the atmosphere 

·         Carbon dioxide is an important gas which has a number of functions: it is crucial to the processes of respiration and photosynthesis, and as a ‘ Greenhouse gas’, it keeps the surface of the planet warm

·         The carbon cycle ensures that the amount of carbon dioxide in store and the amount released into the atmosphere is kept in balance. High carbon dioxide emissions through human activity over the past 200 years have upset that balance.

·         The Earth’s present climate is the result of many interactions:  of volcanoes, the sun, the tilt of the Earth , the movement of continents, as well as human activity

Activity 7

 As we heard in Peter Gibb’s video The Science behind the Climate, the Earth’s climate can be affected by any number of  things.  In this next video, Climate and the Poles , Peter talks about the importance of the polar regions to the world’s climate. Click on this link to watch the video:  

http://news.bbc.co.uk/weather/hi/climate/newsid_8338000/8338854.stm

How do the Arctic and the Antarctic polar regions differ from one another?

What according to Peter Gibbs could be the impact of higher global temperatures on each of the polar regions?

Activity 8

Extreme weather events ( hurricanes, floods, droughts ). Scientists and meteorologists stress that we cannot state that any one particular weather event is due to climate change, but where  there is a trend of those weather events occurring over years or decades, particularly in regions where they had never occurred before, it could indeed signal climate change. Let us take a closer look at a recent example.   

Here is a map of Central America – to the north of the map is Mexico and the USA; to the south is South America.

El Salvador is a small, densely populated country  ( the size of Wales) which suffered a 12 year long, brutal, civil war during the 1980s. In  the 1990s, hundreds of thousands of people who had fled persecution and massacres to live in exile returned to their homeland to start a new life once the war was over and peace accords had been signed.

One such group – a community called Nueva Esperanza  (‘New Hope’) – settled on abandoned land in the fertile, low- lying region of the Bajo Lempa, (circled below on the map ). They were all campesinos – poor peasant farmers - who despite harassment, threats and obstacles from the government and army, built villages, grew crops and established their own local councils based on participatory democracy.  The Bajo Lempa is now home to 28 poor communities who live by growing crops to eat and to sell.

 

One such group – a community called Nueva Esperanza  (‘New Hope’) – settled on abandoned land in the fertile, low- lying region of the Bajo Lempa, (circled below on the map ). They were all campesinos – poor peasant farmers - who despite harassment, threats and obstacles from the government and army, built villages, grew crops and established their own local councils based on participatory democracy.  The Bajo Lempa is now home to 28 poor communities who live by growing crops to eat and to sell.

Alirio Nunez Nunez,  the 28 year old co-ordinator of the Regional Committee for  Community Resilience  in the Bajo Lempa talks here in an interview about his work:

What is the Regional Committee for Community Resilience and why was it set up?

The basic concept behind this committee is to find ways to reduce the impact that destructive forces like floods, hurricanes, earthquakes and droughts have on our communities, and also to develop the capacity to recover quickly after violent natural events.

I have been working as co-ordinator in this committee for the past 5 years. Since 2008, when ACUDESBAL (Association for the Development of Communities in the Bajo Lempa) got funding from Christian Aid, we have been planning projects which help us to improve our ability to adapt and respond to the challenges posed by climate change.

What sort of strategies have you come up with?  We develop awareness about global warming, and we run pilot projects and research into how we can adapt to different climatic conditions.  We  have set up flood early warning systems in each community, so that as soon as we see that the river is going to flood we can mobilise everyone quickly. We have built refuges – buildings that are higher than our normal houses -  where people can go to keep dry if floods are deep, and we have practice drills so that we know what to do in the case of an emergency and can make sure that everyone gets out safely.  We are also leading a campaign to force the government to build decent roads, drainage systems and proper levees.  

Do you think floods are caused by climate change?   We have always had some flooding in the rainy season, but it seems to be getting worse. The rains are getting heavier – for example, in October we had a whole year’s rain in 10 days! Apparently it was the highest rainfall on record for over 50 years.   But it’s not just the rain falling here that causes the flooding.  The river Lempa starts in the mountains in Honduras and runs hundreds of miles to the estuary here. Heavy rains in  Honduras, and in all the places along its course, means that all the streams and rivers feeding into the Lempa get swollen, and the Lempa itself  is a raging torrent by the time it reaches us, resulting in a serious threat to local communities. So it’s the intensity of the rain that is new which we think is due to climate change. 

But there other signs of climate change, too. For example, we now have prolonged droughts of up to two months in the rainy season – that was unheard of in the past.  There is also a general increase in temperature, and more intense heat waves. Sea levels are rising, there is more salt in the ground and more sickness and disease.

As campesinos ( peasant farmers) we have traditionally planted corn in  May - the start of the rainy season - and then harvested it in August.  We have been doing that for generations. But now the weather is so unpredictable that we are having to think about different ways of doing things. We have experimented with planting crops at different times, even planting completely new crops which perhaps are more suited to these wetter conditions. For example, we have never grown rice before, but we think that might work.

How did the floods this year affect you in the Bajo Lempa?   We’ve had enormous losses here, and the most devastating has been the loss of our crops – that would have been food for thousands of people in the area.  The big problem in the short term is to help those in desperate poverty who have lost food, clothing, furniture and animals. We’ve had plenty of promises of aid from the government, but nothing concrete as yet…

Why did you go to Bangladesh?  I was invited by Christian Aid to take part in an international conference of developing countries, to learn how other countries deal with climate change and to share our experiences here in El Salvador.  It was a very positive experience – it helped me to get an overview of what is happening across the world and to share experiences with Bangladeshis who live in climatic conditions that are similar to those in the Bajo Lempa.

How do you see the future?   We know that we are experiencing irreversible climate change, and in the medium and long term  the situation will be critical, with more intense heat, heavier rains, and rising sea levels. Cuban scientists and Salvadorean environmentalists have predicted that we will lose part of the Bajo Lempa as sea levels rise.  On the plus side, here in the Bajo Lempa we are very organised and that helps us to deal with difficult situations of any sort.   We’ll keep on working to improve our living conditions, our crops and to develop community resilience in the face of climate change. 

Below is the lost of losses and damages Nueva’ Esperanza’s agricultural cooperative  suffered during the floods of 2011:

Items                                                           cost in US dollars

crops

6 acres of maize ( corn)                                12,000

8 acres of sorghum                                       10,400

15 acres of pasture                                       12,750

4 acres of sugar cane                                    10,500

50 sacks of fertilizer                                      1,900

Animals;
5 calves                                                        1,250

2 milking cows                                              900

19 pigs                                                         950

25 bags of concentrated animal food             575

Machinery/equipment damaged or lost

Repairs to tractor                                         1,100

Repairs to truck                                            575

new fridge                                                    800

new computer                                              500

furniture                                                      800

Activity 9

Climate Change - How bad is it?

Extreme weather events, such as hurricanes, tornados, droughts and flooding are often cited as evidence that our climate is changing, but scientists have always been very cautious about making bold statements on this  -  until the recent publication of the Special Report on Extreme Weather by the Intergovernmental Panel on Climate Change (IPCC).  This report contains stark warnings for developing countries in particular, as they are likely to be the worst affected, partly because of their geography but also because they are poorer. But the developed world will also be affected.

Climate scientists, using computer models to  predict different scenarios,  believe that global warming could increase the Earth’s temperature by between 2 – 6 degrees.  Two degrees sounds very little, but computer predictions show it could cause massive disruption to the Earth’s climate – a 2 metre rise in sea levels, for example, and a greater incidence of extreme weather incidents.  Whole regions or even some entire countries, such as Bangladesh, Alaska and Florida, would disappear completely  under the sea. In addition, certain animal species like the polar bear may become extinct. The greater the temperature increase, the greater the disruption to climate, and the greater the impact on countries, plants and animals.

 Computer models predict that an increase of between 2 – 5 degrees would drastically impact on climate, but humans would adapt to live in the new conditions.  However,  many scientists believe that if the temperature increase is above 5 degrees, the Earth may become inhabitable for humans and that we would die out as a species.  Most scientists believe the Earth itself would survive and that new species would evolve to inhabit a very different planet from the one we recognise today.

Activity 10:

 Is anybody doing anything?    There is growing awareness of global warming and climate change, and a greater consensus amongst scientists, politicians and the general public that we do need to act soon. There have been several world conferences on these issues , for example at Rio, Kyoto, and more recently in Copenhagen, and while these conferences ended without concrete agreements -  a source of great frustration and disappointment to scientists and activists – they have nevertheless moved the debate on.  There are now many local, national and international initiatives to cut carbon dioxide emissions, for example,  recycling of waste, the development of sustainable housing, alternatives to fossil fuel generated energy, the creation of eco towns, and campaigns to encourage individuals to use energy responsibly.

While it is too early to tell whether these initiatives will impact on global warming, there are some encouraging signs.  Since the 1990s both Poland and Germany have been actively trying to reduce carbon dioxide emissions through a  mixture of legislation, waste management and recycling, and figures suggest that this has worked

End of Course

End of course: You have come to the end of this taster course.  Well done!  You have:

• Learnt what we mean by the terms global warming and climate change
• Read about the role that carbon dioxide plays in life on Earth
• Watched short videos on the science behind global warming and climate change
• Learnt about the impact that climate change is having on a community in El Salvador
• Read short texts on how global warming might affect Earth in the future
• Read about some initiatives to reduce carbon dioxide emissions

This taster is not designed to be a full detailed course, nor claims to provide clear cut answers, but we hope it has perhaps spurred you on to explore some of these issues further.  If you are interested in learning more about any of the themes covered by this taster, there is a list of websites below which you may find helpful.

Now test yourself! How much have you learnt?

1.  Which of these statements is false?

a)  Global warming is not the same thing as climate change

b)  Changes in local weather condition is a definite sign that the climate is changing

c)  Global warming is a reality

2.  Complete the sentence. Only 1 phrase is correct.   Carbon dioxide ….

a) …  causes climate change

b) …. is made up of 2 parts carbon and 1 part oxygen

c) …  is essential for photosynthesis and respiration

3. Which of these is the correct definition of the carbon cycle?

a)  the way carbon and oxygen are recycled in photosynthesis and respiration

b) the way in which the amounts of carbon in store and carbon in the atmosphere are kept in balance

c) the way in which carbon as a greenhouse gas traps the sun’s energy

4. Complete this sentence:  “ If the Arctic ice cap melts …”

a) …  it may cause disruptions to the oceans’ currents

b) ....  it will cause massive flooding

c)  … sea levels will rise

5.  Which is the best answer to this question: “ Are extreme weather events a sign of climate change? ”

a) Yes – and it has been proved by computer tests

b) No -  there have always been floods droughts, hurricanes etc, and always will be

c) Possibly – if there is a trend of those weather events occurring over years or decades

Answers:

1.b                2.c     3.b    4.a               5.c

If you have enjoyed this taster, you may like to try  other WEA on line taster courses. These include:

An Introduction to Globalisation

The Millennium Development Goals

An Introduction to Poetry

Fair Trade

Links

Websites

Arguments & scientific evidence to counter the climate change deniers

Oxfam website on how climate change impacts on poorer countries. There are short videos on what local people are doing in Brazil, Thailand and Bangladesh in the face of climate change to survive. Also, Oxfam’s strategies/campaigns

A clear, interactive animation from the BBC that shows what you can do to reduce your own carbon dioxide emissions, with good impartial information on issues such as solar panels, green roofs, insulation, green shopping etc

BBC website on science and nature that looks at climate change

Greenpeace campaigning site