Describe why we see a seasonal difference in CO2 concentration in the atmosphere

Earth Science

Question 8

Examine the graph below. In your own words, describe why we see a seasonal difference in CO2 concentration in the atmosphere.

From the graph, it is clear that the level of carbon dioxide has been increasing at an alarming rate since the 1960s. The increase in concentration of carbon dioxide in the atmosphere reflects continued burning of fossil fuels, which contributes to accumulation of carbon dioxide in the atmosphere. The seasonal variations in the level of carbon dioxide are due to the processes of photosynthesis and respiration. During the day, plants use carbon dioxide for photosynthesis while at night they use oxygen and release carbon dioxide during respiration. However, the amount of carbon dioxide they take in is much more compared to the one released. This causes frequent variations in the level of carbon dioxide. In addition, during the warm months, plants use more carbon dioxide during photosynthesis and generally grow more. This causes fluctuations in the level of carbon dioxide in the atmosphere.

Question 9

Compare and contrast weather and climate and how the atmosphere affects both

Weather and climate are terms often confused due to their close meaning. Weather refers to the condition of the atmosphere as measured in relatively short period of time. On the other hand, climate refers to the condition of the atmosphere at a particular place and as measured over a relatively long period of time (Barry & Chorley, 2010). The atmosphere contains various elements such as gases, dust particles, and other molecules. These are relatively constant. However, over the last century, the level of carbon dioxide has increased due to human activities. This has caused changes to the water cycle, carbon cycle, and the nitrogen cycle. Increase of greenhouse gases such as carbon dioxide has led to too much heat being trapped in the earth’s atmosphere, hence leading to global warming Barry & Chorley, 2010). This has altered the everyday weather conditions in various places, leading to extreme weather conditions such as flooding, tornadoes, and wide temperature variations. It has also affected climate by changing the average weather conditions of a place over a long period. For instance, some places are facing prolonged dry periods and hence desertification.

Barry, R. G., Chorley, R. J. (2010). Atmosphere, weather, and climate. United Kingdom, UK: Taylor & Francis.

Question 10

In the picture below, explain why the balloons are rising in terms of atmospheric stability. What effect does water vapor have on atmospheric stability?

Atmospheric stability is an assessment of the tendency of the atmosphere to encourage or discourage vertical motion of air. The balloons in the picture rise because they are filled with hot air. Hot air is less dense and tends to rise until it reaches a point where its temperature becomes even with the surrounding temperature. Parcels of hot air in the atmosphere tend to rise, which indicates that the atmosphere is unstable. This is the same for the balloons filled with hot air. The balloons are like parcels of warm air that tends to rise. Water vapor restores the atmospheric stability. When water vapor rises, it reaches the condensation point. This represents a point where the water vapor changes into liquid due to a decrease in temperature. The rising warm air thus encounters a cold front, leading to a balance between the two.

Question 11

Examine the figures below. Contrast the role the greenhouse effect plays in the atmospheres of (a) the Moon, (b) Earth, and (c) Venus.

The greenhouse effect plays a critical role in the atmospheres of moon, earth, and venus. The greenhouse effect refers to the earth’s ability to trap heat and maintain relatively stable temperatures with minimal fluctuations. Due to lack of greenhouse gases on the moon’s atmosphere, wide temperature fluctuations occur. During the day, temperatures can reach as high as 2300 F, while during the day temperatures can reach as low as -2900F (Kutner, 2003). The main reason for the wide temperature fluctuation is that during the night, all heat escapes back into space causing temperatures to drop. The earth’s atmosphere is made of greenhouse gases that trap heat such as methane, water vapor, carbon dioxide, CFC and other non-greenhouse gases. During the day, the earth absorbs the sun’s radiation. Much of this radiation is reradiated into space in form of heat. However, due to the presence of greenhouse gases, some of the sun’s radiation is trapped by the earth’s atmosphere. This makes the earth’s temperature to remain relatively constant during the day and night. Contrary to the above, the temperatures at venus remain extremely high even during the night. This is because venus has a thick atmosphere that is primarily made up of carbon dioxide gas, the main greenhouse gas (Kutner, 2003). As such, venus traps most of the sun’s heat and prevents it from escaping into space, causing a warming effect.

Kutner, M. L. (2003). Astronomy: A physical perspective. Cambridge: Cambridge University Press.

Question 12

Many people confuse the large void in the ozone layer with global warming. Can you distinguish between the two phenomena? Discuss the causes of each. Explain how each process may harm living things. (Refer to the additional reading for this Unit).

The large void in the ozone region represents a layer in the earth’s atmosphere around the Polar Regions where the ozone layer has undergone depletion. Depletion of the ozone layer is the result of human activities such as release of harmful gases into the atmosphere. The release of chlorofluorocarbons (CFCs) from refrigerants and aerosol spray cans is the major cause of ozone depletion (Tabin, 2008). The CFCs causes a chemical reaction with the ozone layer, causing a breakdown of the ozone layer. The ozone layer is significant because it protects living organisms from harmful radiations from the sun. The ozone layer absorbs the radiations thus preventing too much of it from reaching the living organism which may lead to skin diseases, eye damage, cancers, and other diseases.

On the other hand, global warming refers to the warming effect that is caused by accumulation of greenhouse gases into the atmosphere (Tabin, 2008). The two phenomena are similar in that they are caused by accumulation of harmful gases into the atmosphere. In both cases, human activities are the major causes. Global warming is different in that greenhouse gases cause accumulation of excess heat in the atmosphere. The role of greenhouse gases is to trap some of the sun’s heat from escaping into space. However, too much accumulation of greenhouse gases has resulted to more heat being trapped in the earth’s atmosphere, hence higher global average temperatures than normal. A major consequence of global warming is climate change.


Tabin, S. (2008). Global warming: The effects of “ozone” depletion. New Delhi: A.P.H. Pub. Corp.

discussion board question

Click here

to watch the NASA video Temperature Puzzle. Many people are quick to dismiss global warming after a cold winter or a late summer. After watching the video, how would you respond to this person? Why is it difficult to base climate on a single season’s weather? Use data and examples to support your answer. (Note: please base your discussion on what you have learned from the video and textbook reading. This is NOT meant to be a discussion of political ideology.)

My response is that there is clear evidence linking global warming to erratic weather pattern. First, in the last decade, global average temperature has increased by about a third of degree Fahrenheit. Since the first temperature recordings in the 1880s, global average temperature has increased by over 1 degree Fahrenheit. Although the sun’s energy output fluctuates depending on solar cycle, NASA asserts that the last decade has been the warmest decade ever recorded, yet the sun has been on a deep low cycle. Climate cannot be based on a single season’s weather because there are multiple factors that affect weather in time. For instance, solar cycle, wind patterns, pressure, and other factors that affect weather in the short run.

Related: Driefly discuss how the rate of cooling determines the type of rock that forms from magma/lava.