Look at the photos, brainstorm and make a spider graph!

2. Look at the photos, brainstorm and make a spider graph! Leave the bubble in the center empty! We will identify the topic in the end!

4. Did you know??? • If Greenland’s ice sheet melts, sea levels will rise by about 6 metres! • If the Antarctic ice sheet melts, sea levels will rise by about 60 metres! • If the average global temperature rises by 4 degrees Celsius from now, up to 70% of species may become extinct!

5. Earth’s temperatures through the ages • Since its formation 4.5 billion years ago, Earth has ranged from being a molten ball to snow ball! • However, most of this period, Earth was completely ice-free, e.g. during the time of the dinosaurs!

6. Define the following: • Evolution • Ice age • Snowball Earth • Northern Hemisphere • Sediment • Tree rings • Tundra

7. Answers: • Evolution: a process of gradual, peaceful, progressive change or development • Ice age When Earth’s average temperature is lower than usual, and glaciers spread. • Snowball Earth The time when the Earth's surface became entirely or nearly entirely frozen • Northern Hemisphere: The half of Earth above the Equator • Sediment: the matter that settles to the bottom of a liquid. For example rocks at the bottom of the lake. • Tree rings: one of the ​rings that you can ​see in a ​tree ​trunk (= ​centre ​part) if you ​cut through it. Each ​tree ​ring ​shows one year's ​growth. • Tundra: A cold region where the ground is deeply frozen; only the surface thaws (defrosts) in summer, allowing some plants to grow.

8. Not like it used to be! • Today some places on Earth are hot. • Others are covered on ice. • But it wasn’t always so!

9. 4.5 billion years ago… • Our planet was very hot, and soft. No ice anywhere!

10. Earth gradually cooled… • Its surface hardened to a crust, and its atmosphere developed!

11. Since then… • the Earth has warmed up and cooled down many times. For example, 650 million years ago… • …when the only living things were cells. Earth was completely covered in ice. We call it the Snowball Earth!

12. After ice melted, and Earth warmed… • …evolution got a move on. • More and more species appeared!

13. But other ice ages followed… • …and life suffered. Species that could not adapt to the cold were wiped out!

14. However, most of the time, Earth was ice-free! • There was no ice at all when the dinosaurs ruled!

15. Our last ice age began 110000 years ago. • At its peak, ice covered 30% of Earth…. • This included the north of Britain. And the southern part became tundra, where not much could grow!

16. So the people living in Britain left… • …to look for food and warmth in other parts of Europe!

17. The ice age lasted 100000 years! It ended 10000 years ago. Today, ice covers only 10% of Earth!

18. Temperatures since last ice age • We have kept temperature records since only 1850. But scientists nowadays can tell more about earlier temperatures! How?

19. By studying sediment… • …from deep in the floors of lakes and oceans!

20. By studying ice… …from deep in the ice sheets of Antarctica and Greenland!

21. By studying tree rings… • …in the wood of ancient trees!

22. Activity 1 • FALSE! 650 million years ago, at the time of Snowball Earth. Earth was completely covered in ice. (At the peak of the last ice age, which began 110000 years ago, ice sheets covered only 30% of Earth, so they didn’t reach the Equator!) • FALSE! There was no ice on Earth when the dinosaurs lived! • TRUE! • FALSE! Temperatures on the whole planet, and therefore the UK, were extremely hot when it first formed 4.5 billion years ago. Since then the planet (and the UK) have warmed up and cooled down many times! (For example, during last ice age the north of UK was covered in ice and southern part became tundra so the temperature was much colder than now!)

23. Activity 2 • 11000 years ago. The ice age is coming to an end so the ice is melting. People who had migrated to warmer parts of Europe are returning to the UK. • Yes! The graph shows that it was about half a degree warmer approximately 6500 years ago and 4500 years ago. • Approximately 5.6°C. 11000 years ago the temperature was approximately 10.5°C and at its maximum around 6500 years ago it was approximately 16.1°C.

24. We call it global warming! • Today, temperatures around Earth are rising!

25. Why do temperatures change? • Greenhouse gases: Carbon dioxide and Methane Act like a warm blanket around Earth, keeping heat in. They occur naturally in the atmosphere, but we also add some extra.

26. Changes in Earth’s tilt, and its path around the sun • The changes occur in cycles.

27. Changes in the amount of energy the Sun gives out. • These changes occur in cycles too.

28. Important notes! • Some scientists believe that Snowball Earth was due to a big reduction in greenhouse gases in the atmosphere! • Without greenhouse gases, Earth’s average temperature would be about -18°C! • We need greenhouse gases. Without them, all heat would escape from Earth, and we’d freeze at night! • But now we have too much of them!

29. Classwork/homework! • Draw a diagram showing the causes of climate change (global warming). • Add a title and labels to explain it!

30. So what’s causing global warming today?

31. Greenhouse effect GLOBAL WARMING ENHANCED GREENHOUSE EFFECT CLIMATE CHANGE

32. The greenhouse gases

33. Carbon dioxide, CO2 • We breath out CO2 (trees and other plants take it in). • We add extra when we burn coal, oil, gas and petrol. • We also chop down trees, so there is less vegetation to take in CO2. • The level of CO2 has been rising since the Industrial Revolution began, over 250 years ago!

34. Methane, CH4 • Cows, sheep, goats, camels belch out CH4! • It is also given off from swamps, and paddy fields, and landfill sites • Some CH4 escapes from oil and gas wells, as ‘natural gas’! • Every year people raise more animals, grow more rice, extract more oil and gas, and bury more rubbish. As a result, CH4 levels keep rising!

35. Activity 1 • Global warming refers to the rise in average temperatures around the world. • Any two of the following: changes in Earth’s tilt (which affects the amount of solar rays received) and Earth’s path around the Sun (which can become more elliptical and affect the amount of solar rays received) changes in the amount of energy the Sun gives out; volcanic eruptions; meteorite impact.

36. Activity 1c • Humans add two main greenhouse gases to the air – carbon dioxide and methane. • Carbon dioxide is produced when we burn coal, oil, gas, and petrol. It is taken by the trees and plants. We are producing more CO2 than is being absorbed by the trees and plants, and we are also cutting down trees. The excess CO2 remains in the atmosphere. • Methane is produced by animals (such as cows, sheep, and goats) and is also given off from swamps, paddy fields, and landfill sites. The amount of methane is on the increase too. • The molecules in the greenhouse gases absorb the heat given out by Earth and so the average temperatures rise.

37. Activity 2 • We’d die without greenhouse gases, because otherwise all the heat would escape from Earth and we’d freeze. • Greenhouse gases can harm us because they are leading to an increase in global warming. • The two main greenhouse gases are carbon dioxide (CO2) and methane (CH4).

38. 6.3 Climate change

39. Key points! • Earth’s average temperature today is only 4.5 °C higher than it was in the last ice age. Therefore, a rise of just few degrees globally may have catastrophic effects! • As the temperature rises, the patterns of rainfall, wind, and ocean currents (i.e. climates) will change too.

40. It will affect everyone: • Extreme weather events, such as hurricanes, will be more common. • Sea levels will rise, due to melting polar ice sheets and glaciers. It will cause low-lying coastal areas, even entire countries (like the Maldives, Singapore, Bangladesh, and many Pacific islands), to flood. Many of the world’s major cities, such as London, Mumbai, New York and Sydney would also be at risk. • As rainfall patterns change, droughts will occur in some areas and floods in others, which will affect global food production at a time of rapid population growth. • Diseases such as malaria will spread to new regions, as places become hotter and wetter and more suitable for mosquitoes. • The number of environmental refugees will soar as large areas of the planet become uninhabitable.

42. Activity 1 • Temperature will vary across Earth. It will rise more in the northern hemisphere than the southern hemisphere. • The Arctic • Between 2.5 and 3 °C warmer.

43. Activity 3 • TRUE. It may bring some benefits , such as warmer winters, but heat waves will make life unbearable in places. Millions may be forced to flee, as refugees, from disasters such as severe floods, drought, and famine. Wars over water and other resources are likely, as is the spread of disease. • FALSE. It costs a lot to cope with disasters, look after refugees, and treat diseases. People’s livelihoods will be affected if crops fail or tourists stay away from places they used to visit that are now too hot. The cost of many foodstuffs, water, and other essentials is likely to rise as patterns of production and supply change. But new opportunities will open up for some people. • FALSE. Some people will feel their local climate has improved. They may be able to grow new crops where it was once too cold. New tourist resorts will open up. Companies working on ‘green energy’ will flourish. So will companies selling things like fans, air conditioning and umbrellas! • FALSE. All seas around the world are joined. So sea levels will rise everywhere. Low-lying coastal areas around the UK are at risk of being drowned.

44. Activity 4a • POSITIVE CHANGES More hot summer days (summer will last longer!) Fewer very cold days Summers will be drier People will be able to grow new crops (example: peaches, kiwi fruit, sweetcorn) Some places will attract more tourists New breeds of birds are likely to breed in the UK

45. Activity 4a • NEGATIVE CHANGES Low-lying coastal areas are at risk of flooding More extreme weather events, such as heat waves, droughts, gales, and storms Heavy downpours may cause flash floods Rivers are likely to flood due to extreme weather events Animals and plants will have to adapt or will die out.

46. Why is this polar bear getting better at swimming??? Because in the Arctic Ocean, more sea ice is melting each year, and earlier. This means that polar bears, who use it as platform for hunting seals, have less ice and they must swim further for their food – or starve!

47. 6.4 It’s happening already!

48. Activity 1: Location and Annotations • A: Arctic Ocean- more sea ice is melting each year • B: Alaska- permafrost is starting to thaw • C: California and Texas (southwest of USA)- droughts happen more often • D: Peru-glaciers are shrinking and river levels are falling • E: Uganda-drought and floods are becoming more common • F: Pakistan- wheat yields are falling • G: Tuvalu Islands- the islands are flooded because of the rising water levels • H: UK-wildlife patterns are changing

49. Activity 2 • It is where the ground under the surface is permanently frozen in regions of tundra. • Methane, which is a greenhouse gas, is trapped inside permafrost. As the permafrost melts the methane will be released into the atmosphere