7.4 How does global warming affect us?

1. 7.4 How does global warming affect us?

2. What are the consequences of global warming? Consequences of global warming Rising sea levels Changes in climate Changes in world ecosystems Impact on people

3. How do these consequences affect us? 1 Health risks Climate change will alter the distribution pattern of parasites, bacteria and carriers of infectious diseases. For example, tropical diseases such as malaria and dengue fever will spread to present-day temperate areas. Mosquitoes as carriers of infectious diseases

4. How do these consequences affect us? 1 Health risks Hotter summers will lead to more cases of heat-related health problems. In 2006, Germany recorded its hottest summer in history (as of 2006) Mannheim, Germany in July 2006 The local people tried to cool their bodies down in a fountain (Credit: Liang Wing Hang Yanchap)

5. How do these consequences affect us? 1 Health risks Heat waves will become more intense, frequent and long-lasting, therefore causing more deaths. The European heat wave in 2003 caused a large number of casualties Changes in average temperature in Europe from June to August in 2003 Source: UNEP, Environmental Alert Bulletin

6. How do these consequences affect us? 2 Coastal flooding A rise of 1 metre in the sea level is enough to bring disaster to billions of people living in the coastal areas and low-lying countries. What will be the disastrous effects if the sea level rises? The Maldives is the lowest-lying country as well as a famous tourist destination. It will be inundated if the sea level keeps rising More storm surges and frequent coastal ________ flooding Coastal erosion (Credit: Sakis Papadopoulos/Getty Images) The Maldives (Credit: Ng Kim Hung)

7. How do these consequences affect us? 2 Coastal flooding Bangladesh is a low-lying country. A large portion of the country will be inundated if there is a rise in sea levels. What are the consequences? Flooding Inland migration of people Destruction of fertile farmland Loss of life and property

8. How do these consequences affect us? 3 Agriculture and food supply Global warming would lead to ( lower / higher ) evaporation rate which would cause a loss of soil moisture coastal flooding which would destroy farmland warmer and shorter winters, thus, pest may become more active more droughtsand floods which would cause crop failure All these would lead to ( an increase / a decrease ) in food production.

9. How do these consequences affect us? 4 Recreation and tourism The glaciers on high mountains will melt. This will affect ski resorts. Places with mild summers, such as the Mediterranean, would become too hot for summer holidaymakers. Loss of snow cover All these will result in great economic losses. Glaciers on ski slope in the Bolivian Andes (Credit: Reuters/OTHK)

10. How do these consequences affect us? 5 Freshwater supply Air temperature Evaporation rates Rate of water loss from lakes and rivers Melting of glaciers and ice caps Precipitation Freshwater supply

11. Who are the winners and losers of global warming? Winters in cold areas will become less severe Ice melting in the Arctic However, global warming may have positive impact in some areas. shortens shipping routes reduces the number of deaths caused by cold weather makes oil drilling easier Lengthened growing season and longer frost-free period Rainfall in some areas may increase helps ease water shortage problems increases crop yields favours economic development

12. Who are the winners and losers of global warming? What countries will experience a reduction in cereal production? Expected impact of climate change on global cereal production It is generally believed that the less developed countries are the major losers in global warming. This is because they have fewer resources to prevent and lessen the adverse impact of global warming.

13. Who are the winners and losers of global warming? Al Gore, the former US vice president, has been an environmental activist who concerns about global warming. The fact is that the change is so radical and so rapid that it disrupts society and the political structure. It is just a mistake to put it in terms of winners and losers. The earth is the loser. Al Gore, the former US vice president (Credit: Federal government of the United States)

14. Who are the winners and losers of global warming? What climatic changes have been caused by global warming? Hong Kong Impact of global warming on the earth in 2007

15. What are the effects of global warming on Hong Kong? Due to a rise in temperature, coral at the coastal areas of Hong Kong may be bleached. The marine ecosystem will be affected. Rising sea levels will inundate the coastal areas of the major urban areas and the low-lying flat lands in Hong Kong. Mai Po Nature Reserve is under great threat. As temperature rise, evaporation will increase. It will cause more __________. hill fires Please click above for footage

18. 1 Rising sea levels Between 1961 and 2003, global average sea levels have risen at an average rate of 1.8 mm per year. Note: 0 is the global average sea level from 1961 to 1990 Changes in global average sea levels Source: IPCC (2007), Fourth Assessment Report

19. 1 Rising sea levels How will global warming result in a rise in sea levels? Melting of snow and ice cover Running of meltwater into the ocean Global warming Rise in sea levels Thermal expansion of seawater

20. 2 Changes in climate ( Lower / Higher ) evaporation rate Air temperature increases Less precipitation More precipitation Sea level rises The melting of the ice caps release more water into the water cycle.

21. 2 Changes in climate A Changes in precipitation patterns Can you describe the changes in precipitation patterns? Projected changes in precipitation in Northern summer months Source: IPCC (2007), Fourth Assessment Report

22. 2 Changes in climate A Changes in precipitation patterns There is more precipitation in the world as a whole. Some areas will become wetter while some areas will become drier. Projected changes in precipitation in Northern winter months Source: IPCC (2007), Fourth Assessment Report

23. 2 Changes in climate A Changes in precipitation patterns January 1973 February 2007 Lake Chad in Africa (Credit: U.S. Geological Survey) Lake Chad provides freshwater for drinking, sanitation purposes, fisheries and irrigation for millions of people living around it. The size of the lake has shrunk by more than 80% over the past 40 years. Climatic changes caused by global warming are regarded as a factor in the shrinking of the lake.

24. Polar area S N N S Polar area Polar area Temperate area Temperate area Tropical area Tropical area Temperate area Temperate area Polar area 2 Changes in climate B Changes in climatic regions Temperature goes up 2°C 0° When temperature rises, both tropical and temperate areas will extend __________. polewards

25. Air temperature Flooding Drought 2 Changes in climate C More frequent extreme climate events Evaporation rate ( / ) Ocean temperature ( / ) Water vapour in humid regions ( / ) Water vapour in arid regions ( / ) Evaporation in ocean ( / ) Rainfall ( / ) Rainfall ( / ) Intensity of tropical cyclones ( / )

26. 3 Changes in world ecosystems A Desertification Evaporation rate increases Soil moisture is ( reduced / increased ) Soil becomes drier erosion Soil ________ is accelerated Decrease in vegetation cover Such changes threaten arid and semi-arid areas. The pace of desertification will increase.

27. 3 Changes in world ecosystems B Extinction of species Increase in air temperature Climatic changes Changes of the habitats of current species A rise of sea levels caused by global warming will inundate beaches, causing sea turtles to lose their breeding grounds Rapid growth of certain species Extinction of certain species The loss of sea ice reduced the living space of polar bears. They cannot find enough food (Credit: Mayela Lopez/Getty Images) Disturbance to the food chain

28. 3 Changes in world ecosystems C Bleaching of coral The colour of coral comes from the algae that live on it. Warm water kills algae. The coral will lose its colour and become white or bleached. Bleached coral If the situation continues, the coral may die. (Credit: Andre Maslennikov/Still Pictures)

29. 1979 2003 1 Rising sea levels (Credit: NASA) Since 1979, the extent of sea ice cover in the Arctic Ocean has been ( shrinking / increasing ). When meltwater enters the ocean, the sea levels will rise. Other areas in the world will also be affected. Does the melting of sea ice affect only local areas?