Geography Homework Q1a: Using Fig 1, describe how sea surface temperatures over the great barrier reef has changed from 1900 to 2020. The sea surface temperature fluctuates from 1900 to 2020 and increases slowly from 25 degrees Celsius to 27.7 degrees Celsius. Q1b: Explain how this change in sea surface temperature can affect corals in the Great Barrier Reef. The rise in sea surface temperature causes the algae that live in the corals to leave them which results in the corals being white. Due to algae leaving the corals, the corals lose its primary source of food which results in the corals being vulnerable to diseases which may cause the death of the corals. Q1c: Explain another threat to coral reefs that is caused by climate change. Another threat to coral reefs is ocean acidification. The rise in carbon dioxide emissions causes the oceans to absorb the excess amounts. Carbonic acids dissolves calcium carbonate which is required by aquatic organisms. Q2a: Using Fig 2, describe the change in distribution of the black sea bass from 1970 to 2010 and account for the change. In 1970, the black sea bass can be found in the coordinate of 39 degree. However, in 2010 the black sea bass shifted up to coordinate 41 degrees. Due to the rise of sea temperatures, the sea bass moves towards the location where the temperature is more suitable for it to survive. Aquatic species move towards deeper water which is cooler in temperatures. Q2b: Suggest the possible impacts of this change on the composition of the black sea bass’s ecosystem. When the black sea bass moves its location, it affects the existing food webs and aquatic ecosystems. Other aquatic species might flourish when the black sea bass moves there while other species might not. Q2c: Explain how this change can affect fishermen living in the place marker X on the map. Fishermen will catch large amounts of fish around X as there is more black sea bass there. This results them in earning more money. Q2d: Explain how slowing down of global ocean circulation can lead to a disruption in marine food webs. Global ocean circulation allows for the exchange of nutrients between surface and deep waters. The sinking of water at the pokes has been decreasing due to the ocean circulation slowing down. Species that are on top of the food web will suffer from the lack of food such as phytoplantons. Q3a: Describe the change in total global land area affected by extreme and exceptional droughts per month from 1950 to 2020. From 1950 to 2020, the total global land area affected by droughts fluctuates and increases slowly. The extreme drought affected more global land area compared to the exceptional drought. Q3b: Explain how climate change can lead to droughts. The increase in atmospheric temperature increases evaporation of the water. This reduces the surface water and makes the soil and vegetation dry. Countries with dry seasons might feel the environment get more drier. Q4a: Using Fig 4, describe some impacts of tropical cyclones on humans. There is loss of lives due to the flooding, collapsed building and infrastructure caused by tropical cyclones. There are economic losses and food insecurity as the strong winds destroy building and crops. Q4b: Explain how climate change increases the severity and frequency of tropical cyclones. Climate changes causes the water in the ocean to be evaporated faster due to the high atmospheric temperature. This causes more water vapour in the atmosphere which results in stronger tropical cyclones. Q4c: Explain flooding’s impact on terrestrial ecosystems. Intense rainfall can cause floods which destroys habitats. This causes terrestrial species to drown and die. For example, in Assam, India, unusually excessive rainfall in 2020 resulted in floods which killed more than 200 wild animals including eight endangered rhinoceros. Q5a: Using Fig 5, describe the distribution in wildfire risks in the USA. The wildfire risks are minimal to none about 10% to 0% at the north-east direction of United states of America (USA). The wildfire risks are very high about 70% to 100% towards to north-west and southwest direction of USA. There are lesser wildfire risks in the middle of USA about 50%. Q5b: Explain how climate change causes more severe and frequent wildfires. Climate changes causes the temperature to rise which results in drier conditions. This causes the trees and vegetation to die. This makes the wildfire easier to start and harder to put the wildfire out. Q6a: Compare the difference in ice-covered land in the Arctic between 2000 and 2100. The ice-covered land decreases as the years pass by. In 2000, the ice-covered land was 100% in February. In September, the ice-covered land was 50% to 90%. In 2100 February, the ice-covered land will be 70% to 90%. In September the ice-covered land will be 0% to 10%. Q6b: Using an example, explain how the changes in (a) can affect low-lying islands. When sea levels rise, it threatens low-lying islands as it might be flooded. The rise in sea level temperature causes coral bleaching to occur. Q7a: Using Fig 7, describe the changes in the number of dengue cases in Nepal from 2014 to 2019. The dengue cases in Nepal were increasing from 2014 to 2019. In 2014, the dengue cases in Nepal was higher than in 2015 by 201. In 2016, the dengue cases in Nepal were increasing and reached 1529. However, in 2019, the dengue cases in Nepal were at the highest of 14662. Q7b: Using Fig 7, Fig 8 and Fig 9, suggest reasons to explain your answer in (a). Since Nepal is close to the equator, the temperature in Nepal is high. This causes a suitable environment for vector-borne diseases to spread. In colder areas such as the Himalayas, vectorborne disease are hard to spread as it is not a conducive environment for it to survive. Therefore, the vector-borne diseases prefer to move into warmer areas. Q8: Anthropogenic factors cause the largest variation to climate. To what extent is this statement true? 2.2 Anthropogenic factors cause the largest variation to climate is true to a large extent. Since fossil fuels have high carbon content, the burning of fossil fuels such as coal produces large amounts of carbon dioxide and other greenhouse gases which contributes to enhanced greenhouse effect. Fossil fuels create energy through burning for human activities such as agriculture and urbanisation. Another factor is changing land use for agriculture, industries, and urbanisation. For agriculture, forests are cleared so that there is space for crops to grow. Agriculture contributes 30% of global greenhouse gas emissions due to the nitrogen in chemical fertilisers which converts to nitrous oxide. In paddy rice fields, decomposition is rapid due to the high amount of moisture in the soil. For industries, fossil fuels are burned to generate energy to run the machinery and other factory processes. It contributes about 43% of greenhouse gases annually. For urbanisation, which are in cities, fossil fuels are burned to power high concentration of vehicles as well as household activities such as heating and cooling. Cities consume about 78% of the world’s energy and contribute significantly to the emissions of greenhouse gases. Therefore, anthropogenic factors contribute causes the largest variation to climate. Q9: Climate changes causes more direct than indirect impacts to humans. To what extent is this statement true? Climate changes causes more direct than indirect impacts to humans is true to a large extent. The first factor for direct impact is extreme weather events. Heat wave is a period of excessively hot weather that is abnormal usually lasting for several days or longer. Climate change leads to higher temperatures, making the heat waves more intense and more frequent. People may suffer from heat strokes, difficulties in breathing and death. High temperatures can deplete the soil moisture leading to widespread crop failures, affecting food supply. For example, in 2003, a heat wave hit Europe which caused 70000 people to die as it lasted over two weeks. The harvest for agricultural crops such as wheat was also affected as many crops died. This increased the price of bread significantly and food became less affordable for people. The second factor for direct impact is droughts. Drought is when an area or region experiences a lack of precipitation such as rain or snow for an extended period of time resulting in water shortage. Warmer atmospheric temperatures due to climate change increase evaporation which reduces surface water and dries out soil and vegetation. In areas with dry climate, the dry seasons may therefore get even drier. Shortage of clean water can lead to dehydration and death. Lack of water can also cause crop failure and people may die from hunger or be malnourished. For example, the drought that was in Afghanistan in 2018 to 2019 affected more that two thirds of the country. Over ten million people were affected due to a lack of food. Therefore, Climate changes causes more direct than indirect impacts to humans.
