Borrowed Time on Disappearing Land
Facing Rising Seas, Bangladesh Confronts the Consequences of Climate Change
Introducing Bangladesh
“One of the poorest countries on Earth, Bangladesh has made remarkable strides since gaining its independence in a war with Pakistan in 1971. On December 15, 2016, I met with A.B.M. Fazle Karim Chowdhury, a Member of Parliament, who explained, with a measure of pride, “once there was a shortage of food, now we export food.” Bangladesh once led the world in child mortality. No longer. Due to better health care, life expectancy rose by 10 years, from 59 to 69 between 1990 and 2010. Providing free birth control empowered women and reduced the fertility rate from seven children per woman to three, which is substantially lowering population growth rates. Universal primary education is helping to create a more skilled workforce. Perhaps most impressive, the poverty rate declined from 57 percent to 25 percent between 1990 and 2014. With GNP rates annually hovering around seven percent, MP Chowdhury has reason to proclaim, “We are a developing country. Soon, we’ll be a developed country.””
The Unfolding Tragedy of Climate Change in Bangladesh Author: Robert Glennon, Scientific American Apr 21, 2017
Task 1: Bangladesh Country Overview.
Complete the Case Study Overview for Bangladesh. How developed is Bangladesh?
PROCESS: THE EVIDENCE FOR CLIMATE CHANGE AND WHAT MIGHT BE CAUSING IT.
A) Is Climate Change to Blame for Bangladesh’s Problems.
Key Question: What is the evidence for global Climate Change?
The Evidence for Climate Change
i) Average Global Temperature Increase
Task 2: Increasing Global Average Temperatures
Describe the change in Global Temperatures shown in the graph above. Include data from the graph with your description. Insert the graph above your description.
ii) Declining Polar Ice Cover
Antarctica
Greenland
Task 3: Ice Loss
Describe and compare the change in Ice Mass for both Greenland and Antarctica using the graphs and videos above. Try to account for any differences you see in the rates of ice loss.
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Task 4: Further Evidence
We have already seen evidence of increasing global temperatures and declining ice cover but there is plenty of other pieces of evidence that suggest the climate is warming.
Click on this link and use the information to summarise the other evidence for Climate Change.
Task 5: Evaluation- How compelling is the Evidence?
For each piece of evidence you have considered, I would like you to give it a score out of 5 based on how strong you think the evidence is. 1 for the weakest evidence and 5 for the strongest. How easy was it for you to score them?
Task 6: Synthesis and Evaluation- Cause or Consequence?
How are these pieces of evidence connected. Could some of the pieces of evidence also be contributing to the problem. Can they be both cause and consequence? Use a mind map to try and link the pieces of evidence together. Does this make you reconsider the scores you gave to each piece of evidence in task 5?
TOK Questions:
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Much of the evidence used to support the theory of Climate Change has been gathered by NASA. To what extent does this impact how we treat the evidence? Can we trust the data?
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Read the statement on the right. What is meant by the term, “Scientific Consensus?”
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Look at the list of organisations who have reached this, “Consensus.” What questions would you want answered before you were able to trust their opinioins.
B) What’s Causing Bangladesh’s Problems? The Causes of Climate Change
Key Question: What are the natural processes that can influence the atmospheric energy balance and what impact can they have?
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How does the Climate System Work: The Energy Balance
Task 1: The Earth’s Energy Balance
Look carefully at the diagram above and the web page linked to it. Write a concise description of the Atmospheric Energy Balance.
Evaluation: Of the processes shown in the diagram above, which do you think can be altered by human activity?
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What happens when the balance is upset?
“Climate forcing is the difference of radiant energy (sunlight) received by the Earth and the outgoing longwave radiation back to space. The radiative forcing is quantified based on the CO2amount in the tropopause, in units of watts per square meter to the Earth’s surface.[25] Dependent on the radiative balance of incoming and outgoing energy, the Earth either warms up or cools down. Earth radiative balance originates from changes in solar insolation and the concentrations of greenhouse gases and aerosols.” wikipedia
Skill: Scanning an article.
Task 2:
The ability to quickly scan an article for key points is essential. You have 5 mins to read the wikipedia article that the above quote was taken from. Make notes.
Your notes will be scored on the number of accurate facts you have recorded, their importance to the key question and the level of understanding you show when you discuss them.
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The Natural Factors Driving Climate Change:
Task 3: What do you think.
Look again at the Energy balance diagram in Task 1. Which elements of the energy balance could be altered by natural phenomena?
Make a quick brainstorm on how they could change and what might cause them.
Factor 1) Is the Sun to Blame?
“In the last 35 years of global warming, the sun has shown a slight cooling trend. Sun and climate have been going in opposite directions. In the past century, the Sun can explain some of the increase in global temperatures, but a relatively small amount.” It’s the sun http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm
Task 4:
1) Describe the variation in Solar Irradiance since 1880 shown in the graph above.
2) Read the text in the box below about the impact of Solar Irradiance on climate change. How do you think a climate change sceptic would respond to this piece of text? Come up with a series of questions and comments that a sceptic might ask.
Other Factors Affecting the Balance Between Incoming and Outgoing Radiation:
Albedo
The reflectivity or albedo of the Earth’s surface varies with the type of material that covers it. For example, fresh snow can reflect up to 95% of the insolation that reaches it surface. Some other surface type reflectivities are:
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Dry sand 35 to 45%
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Broadleaf deciduous forest 5 to 10%
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Needleleaf confierous forest 10 to 20%
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Grass type vegetation 15 to 25%
Reflectivity of the surface is often described by the term surface albedo. The Earth’s average albedo, reflectance from both the atmosphere and the surface, is about 30%. (From PhysicalGeography.net)
