Climate Change and Biomes

Transcription

1 Climate Change and Biomes Key Concepts: Greenhouse Gas WHAT YOU WILL LEARN Biome Climate zone Greenhouse gases 1. You will learn the difference between weather and climate. 2. You will analyze the effect of climate on biomes. 3. You will analyze precipitation and temperature maps and predict their impact on the biomes of North America. Activities for Conceptualizing Climate and Climate Change 1

2 Engage Your Thinking How does climate influence natural habitats (biomes)? How might climate change affect the distribution of biomes? Can biomes affect climate? To answer these questions, graphs, temperature and precipitation maps, and climate zone maps are provided for you to compare to biome maps. First, however, answer the following questions to help you reflect on what you already know about the topic of climate change and natural habitats (biomes). 1. How does climate influence biomes? 2. How might climate change affect biomes? 3. How might biomes affect climate? Explore and Explain What is the difference between weather and climate? Weather is the physical condition of the lower atmosphere, the temperature, precipitation, humidity, wind speed, and cloud cover for a given geographic location over a short time period, such as a day or week. Thus, weather changes from day-to-day and from location-to-location. Climate, however, concerns the weather patterns for larger regions over longer periods of time. Although weather varies from day-to-day, the same type of weather will reoccur over the years for a given Biome Components Biomes are made up of abiotic (nonliving) and biotic (living) components. Abiotic components include water, air, soil, temperature, and solar energy. Plants, animals, and microbes make up the biotic component of a biome. Activities for Conceptualizing Climate and Climate Change 2

3 location. The recurring weather pattern for a location is known as its climate. A climate is the set of the most characteristic weather conditions for a location over a 30-year period. For example, the weather in Indiana changes from day-to-day, but the overall climate features warmer weather in the summer and colder weather in the winter. Climate plays an important role in the way the land areas of the Earth develop. The land (terrestrial) portion of the Earth is divided into four main climatic regions: polar, subpolar, temperate, and tropical. A biome is a very large area within a region in which the soil types, plants (vegetation), and animals are all very similar. Climate and vegetation vary with distance from the equator (latitude) and by altitude (elevation). A biome is identified mainly by the type of vegetation that grows there; its climate, especially temperature and precipitation, determines the type of vegetation that may grow in a particular area (Figure 1). Where climatic conditions are similar over time, specific plants evolve because they can survive in that climate. The type of vegetation, in turn, determines the type of animals that can be found there. When climatic conditions change, the types of vegetation, and the types of animals that are dependent on this vegetation, change. Figure 1. Average temperature and precipitation determine the type of biomes (Source: Macmillan Publishing Company) Activities for Conceptualizing Climate and Climate Change 3

4 4. Figure 1 shows the temperature and precipitation trends on the edges of the four main climatic zones. How does climate (temperature and precipitation) determine the type of biome found in an area? 5. Based on Figure 1, if the climate for a coniferous forest biome became warmer and wetter, which type of biome might it become? Throughout the world, we find 12 distinct biomes. North America is divided into 8 different biomes based on the dominant type of vegetation found in a given geographic area (Figure 2). The type of vegetation influences the types of animals found in each biome. Figure 2. Biomes of North America (Source: Missouri Botanical Garden) Activities for Conceptualizing Climate and Climate Change 4

5 6. Based on Figure 2, in which biome is your school located? Land areas can also be organized by climate zones. Climate zones differ from biomes because they are determined primarily by the topography and climatic conditions of given areas, especially average temperature and precipitation. For example, mountains create warmer and drier climatic conditions on the leeward side (the side away from the direction the wind blows). The biome (plants, animals, weather patterns) in such areas is often a desert. Although climate determines the biome for a given geographic area, a biome may also affect climate. For example, forest biomes have a climate-buffering effect. Deciduous forests tend to reduce wind velocity 60%-80% when compared to non-forested areas. The type and density of forest foliage (leaves) affects the amount of the sun s energy that reaches the forest floor, which impacts soil evaporation. At the same time, dense forest vegetation increases transpiration. Thus, in general, forest humidity is 2%-10% higher than in non-forested areas. The forest canopy also helps to moderate temperatures, resulting in lower maximum temperatures and higher minimum temperatures than non-forested areas. 7. How might deforestation the clearing of forests for agricultural purposes affect climate? Extend Your Thinking Carbon dioxide, water vapor, nitrous oxide, and methane are naturally occurring gases in the Earth s atmosphere. These gases let the sun s energy pass through the atmosphere and reach the Earth s surface, where some of it is absorbed and changed into heat. This heat is radiated back into the atmosphere. The carbon dioxide, water vapor, nitrous oxide, and methane in the atmosphere trap some of this heat and re-radiate it back towards the Earth s surface, warming the Earth. Carbon dioxide, water vapor, nitrous oxide, and methane are known as greenhouse gases and this natural process is called the greenhouse effect (Figure 3). Activities for Conceptualizing Climate and Climate Change 5

6 The atmospheric concentration of greenhouse gases, especially carbon dioxide, has increased since the Industrial Revolution. The increase in greenhouse gases is primarily caused by the burning of fossil fuels (oil, natural gas, and coal). The increase in atmospheric greenhouse gases is causing less heat to escape the Earth s atmosphere. As a result it is warming up, bringing about changes in temperature and precipitation patterns that are changing the Earth s climate. The following maps Figure 3. The greenhouse effect show the surface (Source: EPA) temperature changes (Figure 4) and precipitation changes (Figure 5) for the world from Figure 4. Surface temperature change (Source: National Geographic) Activities for Conceptualizing Climate and Climate Change 6

7 Figure 5. Precipitation change (Source: National Geographic) 8. Based on Figure 4, describe how the surface temperature for the U.S. has changed: 9. Based on Figure 5, describe how the average precipitation for the U.S. has changed: 10. Based on Figures 4 and 5, describe how the climate for the U.S. might have changed from the : Activities for Conceptualizing Climate and Climate Change 7

8 11. Explain how the change in temperature and precipitation might affect the biomes in North America: Future changes in U.S. temperature and precipitation are predicted to cause a change in the geographic distribution of forest types, as well as a change in the composition of forests. Increased temperatures and decreased precipitation increase the risk of forest fires and the susceptibility of trees to insect pests and diseases. These changes in temperature and precipitation are predicted to change forest fire patterns and the diseases that impact the survival and geographic distribution of tree species. Apply What You Have Learned The predicted precipitation and temperature changes for the U.S. for the year 2050 are shown in Figures 6 and 7. These might cause a change in climate that could impact the biomes found in the U.S. Figure 6. Predicted change in temperature for 2050 (Source: GFDL) Activities for Conceptualizing Climate and Climate Change 8

9 Figure 7. Predicted change in precipitation for 2050 (Source: GFDL) 12. Based on the predicted temperature and precipitation data shown in Figures 6 and 7 and the current North American biomes (Figure 2), create a biome map for North America for the year Use the map below to create your biome map. Your map should show where you think the North America biomes will be geographically located in Explain how your biome map is similar or different to the current North American biome map shown in Figure 2 Activities for Conceptualizing Climate and Climate Change 9

10 Reflect on What You Have Learned Now that you have learned about climate and biomes, think again about the questions you answered at the beginning of this activity and discuss whether your ideas have changed or whether they have stayed the same. 14. How does climate influence biomes? Activities for Conceptualizing Climate and Climate Change 10

11 15. How might climate change affect biomes? 16. How might biomes affect climate? 17. How my ideas have changed: Activities for Conceptualizing Climate and Climate Change 11