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Published by
Australian Academy
of Science
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Activity 2 | Excuse me! The problem with methane gas |
Changing methane levels: A worksheet
- Use the data in the table below to produce a line graph showing how the levels of methane in the atmosphere have changed since 1850.
- Now plot the world population and temperature data on the same graph using the secondary Y-axis.
Global changes in atmospheric methane levels, world population and air temperature from 1850-2007
Year
|
Methane level1
(ppb) |
World population2
(billion people) |
Relative temperature3
(°C)
|
1850 |
791 |
1.2 |
-0.4 |
1900 |
879 |
1.6 |
-0.3 |
1925 |
1007 |
2.0 |
-0.3 |
1950 |
1147 |
2.5 |
-0.3 |
1975 |
1465 |
4.0 |
-0.2 |
2000 |
1752 |
6.1 |
+0.3 |
2007 |
1784 |
6.6 |
+0.4 |
1 Source: http://www.pnas.org/content/101/46/16109
2 Source: http://www.digitalsurvivors.com/archives/worldpopulation.php
3 Source: http://cdiac.ornl.gov/ftp/trends/temp/jonescru/global.dat, relative to the 1961-90 mean.
- Describe how the concentration of methane in the atmosphere has changed over time.
- Is there any relationship between the levels of methane in the atmosphere and the world population? Why do you think this has happened?
- What developments occurred during the 19th century that could be responsible for increasing greenhouse gas emissions?
- When was the most rapid rise in methane levels?
- Does this correspond to the most rapid rise in temperature? Explain your answer
- What other factors could be contributing to this rapid rise in the global temperature?
- If we don’t do anything to limit human-induced greenhouse gas emissions, predict methane levels in 2025.
- Find out what the term ‘positive feedback’ means in science and explain how this term could be used when describing future levels of methane.
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