Climate and Change 5

2.2 What challenges might our future climate present us with? Title: Changing the Atmosphere Learning Objectives: To understand that the difference between the Greenhouse Effect (natural) and the Enhanced Greenhouse Effect (influenced by man) To understand what activities (natural and man-made) contribute to carbon dioxide emissions and other greenhouse gases Key vocabulary: Atmosphere Greenhouse gas Greenhouse effect (natural) Carbon store Enhanced Greenhouse Effect (man-made) Carbon dioxide emissions Methane Nitrous oxide Parts per million

Lessons from the past? Remember this slide from the lesson before? We are now going to consider more recent changes – i.e. from the mid 19th Century onwards

Carbon dioxide and temperature levels over the last 800,000 years

What Gases make up the Atmosphere. Watch: http://www. bbc. co What Gases make up the Atmosphere? Watch: http://www.bbc.co.uk/learningzone/clips/carbon-dioxide-in-the-atmosphere/4417.html and label the following pie-chart, stating the % and saying why each gas is important (Digby P. 32)

Activities Now watch http://news.bbc.co.uk/hi/english/static/in_depth/sci_tech/2000/climate_change/greenhouse/default.stm Define - Greenhouse Effect. Define - Atmosphere On your diagram of the Greenhouse Effect, quickly add labels from Digby P. 32. Write a brief explanation of how the Greenhouse Effect works – make sure you explain that it is a natural process – and what the Earth would be like without it e.g. without it Earth would be up to 30˚C cooler – too cold for humans to exist

The Greenhouse Effect

The Greenhouse Effect

Pearson P. 37

Greenhouse Gases Look at the table below or in Digby P. 32 Which of the Greenhouse Gases is most common? How is this produced naturally? Why are plants and trees called a carbon store? What happens when deforestation takes place? What other human activities have boosted carbon dioxide levels?

Greenhouse Gases Greenhouse gas % of greenhouse gas produced Sources Warming power compared to carbon dioxide % increase since 1850 Carbon dioxide 89% Burning fossil fuels (coal, oil, gas), deforestation which produces carbon dioxide 1 + 30% Methane 7% Gas pipeline leaks, rice in paddy fields, cattle farming. 21 times more powerful + 250% Nitrous oxide 3% Jet aircraft engines, cars and lorries, fertilisers and sewage farms. 250 times more powerful + 16% Halocarbons 1% Used in industry, solvents and cooling equipment. 3000 times more powerful Not natural

Greenhouse Gases Year ppm 1800 1820 1840 1860 1880 1900 1920 1940 1960 Looking back at the previous table we can see that there are other greenhouse gases. Copy out: Methane emissions result from: The raising of livestock – recent estimates by scientists suggest that wind given off by cattle makes up 11% of Australia’s carbon footprint. The production and transport of coal, natural gas and oil The decomposition of organic wastes (such as uneaten food) in landfill sites Nitrous oxide emissions result from: Agricultural and industrial activities Combustion of solid waste and fossil fuels. Look at the table below Draw 3 line graphs to show the rise in the 3 main greenhouse gases (you will need a different scale on the left for carbon dioxide and nitrous oxide than you will on the right for methane) (ppm stands for parts per million). Year ppm 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 CO2 280 282 283 287 291 295 299 310 323 347 386 Methane 700 713 727 756 796 835 871 980 1430 1656 Nitrous oxide 270 271 275 276 286 290 294 304 311 318

Facts about the growth of greenhouse gases over time Copy out and choose correct number: The world current level of CO2 is the highest reached for [650,000/ 20 million years]. Even worse it is increasing now at a rate [100/200 ] times faster than at any time in the last [1000/ million years]. Since the 1800s, CO2 concentration has increased beyond its natural amount by about [1/3 or 1/6]. Methane concentration has more than [halved/doubled] since 1800s. Nitrous oxide concentration has grown less, but has still risen by [16%/60%]. ANSWERS …WAIT FOR IT … ARE ON THE NEXT SLIDE!!!!!!!!

Facts about the growth of greenhouse gases over time Check – were you right or wrong?: The world current level of CO2 is the highest reached for [650,000/ 20 million years]. Trick though because some people have estimated the second answer!! Even worse it is increasing now at a rate [100/200 ] times faster than at any time in the last [1000/ million years]. Since the 1800s, CO2 concentration has increased beyond its natural amount by about [1/3 or 1/6]. Methane concentration has more than [halved/doubled] since 1800s. Nitrous oxide concentration has grown less, but has still risen by [16%/60%].

The Enhanced Greenhouse Effect Normally the Greenhouse Effect is like a blanket – you wouldn’t want to take it off because you would be too cold – however putting another blanket on would make you too hot. The human-produced greenhouse gases are like this extra blanket, resulting in what is called the Enhanced Greenhouse Effect. … and if more people around the world do not change their lifestyles, the greenhouse effect will be enhanced further, with more ‘blankets’ being added to the atmosphere – a sure recipe for sleepless nights! Use the information above and Digby P. 34 to help you answer the EXAM STYLE QUESTION: What is the enhanced greenhouse effect? (3 marks)