Higher Geography

1. Higher Geography Global Warming

2. Higher Geography Global Warming

3. Learning Intentions Define Global Warming To know the difference between weather and climate Investigate the sources of evidence for climate change

4. What is Global Warming? • Definition - a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.

5. Weather and Climate When talking about global warming / climate change it is important to know the difference between weather and climate: • Weather – the condition of the atmosphere at any given time • Climate – the average weather conditions of an area, usually taken over a period of about 30 years

6. Sources of Evidence for Climate Change • Scientists generally agree that earth is experiencing climate change – this has also happened several times in the past • The consensus is based on evidence collated from a variety of research methods • One method of evidence on its own would not have made scientists agree – the extent of evidence available means that climate change is recognised as a continuing process

7. Sources of Evidence for Climate Change Sources of evidence come from 3 main areas: • Palaeoclimatology • Archaeological / historical • Modern scientific data collection

8. Task • Read pages 97 – 103 (only left side of this page) • Answer the following questions in the form of a large poster: • Describe the difference between climate and weather • What is climate change and how does it differ from global warming? • Produce a spider diagram or mind map showing the 3 methods used to provide evidence of climate change (summarise these methods) • Write an account of what research into climate change has shown

9. Cause of Global Climate Change • Various influences shape and change our climate These can be referred to as: • Climate drivers • Climate forcing mechanisms • Climate forcings It is now understood that there are not only the physical drivers that affect climate change but human activities have also been identified as being an additional driver

10. Climate Feedback Climate Feedback – this is the process through which changing one element has a knock-on effect that alters another It can even result in a domino effect, causing multiple variations in the system Positive feedback amplifies a change while negative feedback reduces it

11. Feedback Effects • An example of a physical driver resulting in a positive effect would be increased areas of ice or snow • This result in the reflective quality of the surface increasing and so stimulating further cooling • This in itself encourages more snow and ice cover that further amplifies the effect

12. Feedback Effects • An example of anthropogenic drivers resulting in feedback would be increased amounts of greenhouse gases within the system • This triggers increased heating in the atmosphere which then warms the seas and oceans causing more water vapour to be released • This intensifies the greenhouse effect and a self-reinforcing cycle is in motion

13. Greenhouse effect is enhanced Larger amount of water vapour in the atmosphere Atmospheric temperature increases Increased heating of bodies of water (e.g.oceans) resulting in a rise in the level of evaporation Positive feedback cycle driven by additional greenhouse gases

14. Physical drivers of climate change (natural forcings) • Energy emission by the Sun • Variations in the Earth’s orbit and movement • Eccentricity (the stretching orbit) • Axial precession (wobble) • Axial obliquity (axil tilt) • Meteorite impact • Volcanic activity

15. Physical drivers of climate change (natural forcings) • Depletion of ozone • Acid rain • Gas release at the Earth’s crust • Impact of flood basalt eruption: Siberian Traps • Impact of underwater methane gas • Impact of flood basalt eruptions: Deccan Traps

16. Physical drivers of climate change (natural forcings) • Plate tectonic movement • Plate tectonic movement and volcanicity • Plate tectonic movement and location of landmasses • Plate tectonic movement and increased altitude of land • Plate tectonic movement and oceanic circulation change

17. Anthropogenic (human) drivers of climate change (anthropogenic forcings) Sources of human activity related emissions: • Industry • Deforestation • Livestock rearing • Additional carbon dioxide in the atmosphere • Ocean acidification • Acidification and its impact on marine organisms • Thermohaline circulation

18. Task • Complete the tasks on page 126 • Complete the tasks on page 132

19. Global and Local Effects of Global Climate Change • Look at figure 3.7 on page 134 and discuss the examples of predicted climate change in the next 100 years • Summarise these in a spider diagram.

20. Case Study - Tuvalu • This is a small, Polynesian island state in the Pacific Ocean midway between Hawaii and Australia • It is the fourth smallest country in the world and a member of the Commonwealth • With its highest point only a few metres above sea level it is the country with the second lowest maximum height • Its highest point is on Niulakita (island) at 4.6 m

22. Tuvalu • Its population in 2013 was 9876 – this is low but it has a high population density of 379 people per km2 • It has a mixed market subsistence economy but is not self sufficient in agricultural production • Tuvalu is very vulnerable to the effect of climate change and in particular to rising sea levels and salinisation

23. Projections, problems and responses • Projections show that Tuvalu may become uninhabitable in 50 – 100 years • The last remaining island will vanish beneath the Pacific Ocean by 2100 • Scientist believe that Tuvalu will become the first nation to disappear due to the effects of global warming

26. Tuvalu now and in the future Air Temperature • Expected to increase by up to 4 degrees by 2100 • Increased number and intensity of extreme heat days and warm nights • Decline in cooler weather • Not in the hands of the islanders

27. Tuvalu now and in the future Ocean Temperature • These will continue to rise – linked to temperature increase and acidification the surrounding sea area is experiencing a reduction in numbers and diversity of fish types • Expansion of ocean water due to increasing temperatures resulting in flooding incursions – increased coastal erosion and loss of land

28. Tuvalu now and in the future Ocean Temperature - response • Not in the hands of the islanders • Coastline protection on a large scale is not affordable for the Tuvaluan government

29. Tuvalu now and in the future Precipitation • Predicted increase in average annual and seasonal rainfall – increases during the wet season while dry seasons intensify resulting in drought • Increased intensity and frequency of extreme rainfall days • Some areas experience a 75% reduction in the ability to grow pulaka

30. Pulaka – grown in Tuvalu as a source of carbohydrate It needs to be cooked for hours to remove toxins – but rich in nutrients, especially calcium

31. Tuvalu now and in the future Precipitation • Tuvalu is now relying on imported food • The only freshwater on the island is deposited by rain • Groundwater is limited and is becoming undrinkable due to seawater contamination of the island’s aquifers • Rainwater harvesting is a major source of water – periods of drought are expected to increase

32. Tuvalu now and in the future Precipitation - responses • The UN’s Food and Agriculture Organisation is financing the introduction of salt-resistant banana plants and taro roots to provide a replacement food supply • Mangroves are being planted at the coastline in a double effort – to prevent erosion and provide a habitat for fish (part of islanders diet)

33. Tuvalu now and in the future Precipitation – responses • Desalination has become a major source of fresh water – Japan funded the purchase of desalination units in 2006 and 2011 and Australia and New Zealand provided temporary units to respond to drought conditions in 2011 • The EU and Australia provided water collection tanks – it would have been very difficult for the Tuvaluan Government to have afforded such support mechanisms and machinery

34. Evacuation, refugees and culture • Tuvaluans are well aware of their situation • They may have to leave their islands within 100 years • There are already areas that are uninhabitable • They do not want to leave but may have no option • Negotiations have started with New Zealand and Australia about immigration programmes • There is the fear that once the people leave the islands their culture will be lost forever

35. Effect of climate change on Scotland - Task • Using Figure 3.57, produce a mind map of the projected climate change effects on Scotland

36. Management strategies and their limitations • Action is required on both a global and local levels if climate change is not to reach a level that is unmanageable and harmful to our environment and even the continued existence of human beings on our planet • What needs to be done??

37. Management strategies and their limitations A worldwide approach is vital if we are to ensure; • A reduction of carbon emissions and those of greenhouse gases in general • Research, investment in and utilisation of technologies that will assist in reducing greenhouse gas emissions and those that will assist with adaptation to change • Reductions in forest loss • Assistance to those countries economically less able to reduce emissions or to adapt to change

38. Tackling the problem of global warming

39. Worldwide agreements • In 1992 at the Rio Earth Summit in Brazil, 162 countries resolved to stabilise greenhouse gas concentrations in the atmosphere • This was followed by conferences in 1997 at Kyoto in Japan, 2000 in The Hague, Netherlands and 2005 at Gleneagles in Scotland • Not all countries agreed and some didn’t attend, but the process was moved forward.

40. Worldwide agreements • In 2014 at the Summit in New York three of the world’s largest economies and greenhouse gas emitter (USA, China and India) pledged to take action and set targets

41. Worldwide agreements • Governments, business, civil society and investors announced actions to assist: - In the reduction in emissions - promote increased scientific investigation as well as development of emission lowering and mitigation technologies- pledges to take action on energy generation, transport, industry, agriculture, cities, forests and building resilience

42. When does climate change become reversible? • United Nations agree that an increase of 2 degrees is the ‘tipping point’ for our planet’s climate system • Further increase would be irreversible • Global temperatures have already increased by 0.5 degrees since industrialisation • Without action, models suggest that there could be another 2-3 degrees rise in the next 50 years

43. Predicted results following the 2 degree increase level • 4 billion people would experience water shortages • An additional 200 million people would suffer from hunger • Crop yields would drop by 30% across Africa • A further 60 million people in Africa would become exposed to malaria • Up to 40% of wildlife species would become extinct Unfortunately, the United Nations recognises that they will not do enough to hold global warming below 2 degrees

44. Failing crop yields in many areas, particularly LEDCs Food Possible rising yields in some high latitudes Falling yields in many MEDCs Water Small mountain glaciers disappear – water supplies threatened in several areas Significant decreases in water availability in many areas, including Mediterranean and southern Africa Sea level rise threatens major cities Rising number of species face extinction Ecosystems Extensive damage to coral reef Extreme weather events Rising intensity of storms, forest fires, droughts flooding and heatwaves Risk of abrupt and major irreversible changes Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system 3 5 1 2 4 0 Global temperature change (degrees Celsius) Projected impacts of climate change