Science Makes Sense Week 8: Chemistry and Social Justice: burning of fossil fuels, climate change, carbon dioxide,methane levels and the monarch butterfly

There are many topics I will cover under Chemistry and Social Justice, but the excessive use and  burning of fossil fuels and its consequences seem the most urgent and grave topic for us all right now.

As some of you already know, those of us who live in the United States, know that we are dependent on fossil fuels for most of our energy sources. Today you will see through chemical reactions, what happens when fossil fuels/petroleum by-products are burnt. Petroleum by-products includes all the hydrocarbons, alkanes ,plus several derivatives that we use as fuels. When methane, ethane, propane or any alkane  burns, it combines with oxygen to give carbon dioxide and water. This is an oxidation reaction we studied (Week 2).The amount of carbon dioxide and water produced varies with the alkane; the higher the number of carbon atoms, the more carbon dioxide is produced:

CxHy + aO2 –> bCO2(g) + cH2O(g) ..                      

As you can see  x=b  which means that the higher the number of carbon atoms, the greater will be the molecules of carbon dioxide emitted; let me prove it to you with some examples:

CH4    +  2 O2      →   CO+  2H2O

2C2H6   +    7O2  →   4 CO2   +   6H2O

C3H8   + 5O2        →    3 CO2   +  4H2O

2C4H10  + 13O2    →   8 CO2   +  10H2O    

The ratio of alkane to carbon dioxide is 1:1 for methane, 1:2 for ethane and by the time you get to butane, the ratio is 1:4, which proves the statement before the equations, viz., the higher the alkane the greater the molecules of carbon dioxide produced. The amount of carbon dioxide produced has been increasing more rapidly in the 20th and 21st century, and there is a direct correlation between the increase in the amount of fossil fuels burnt in this period and the rise in carbon dioxide in parts per million (ppm)(Ref.1,3)


The concentration of carbon dioxide levels has been monitored since the late fifties of the 20th century by scientists. However, air trapped in the snows of Antarctica have led to data on carbon dioxide levels for the past 160,000 years. These studies indicate that as the amount of carbon dioxide(CO2) increased, the global temperature increased as well. Now the levels of CO2 have remained fairly constant from the last Ice Age (100,000 years ago) until the Industrial Revolution which took place in the late 18th to mid 19th  century. However, a greater rise occurred in the 20th century (greater production and use of fossil fuels in developed and developing countries) and is rising even more dramatically in the 21st century where we have reached critical and dangerous levels.

How exactly does the increase in carbon dioxide lead to climate change? The CO2 rises to the atmosphere and forms an  invisible barrier or layer around the earth, almost like a glass in a greenhouse (the earth being the greenhouse) leading to the phenomenon we call ‘global warming’ or climate change.  CO2 and CH4 (methane; see next paragraph after this)  trap heat near the surface of the earth. While the sun’s radiation strikes the earth and warms it up and the warmed surface re-radiates this energy as heat, the gases absorb some of the heat which then warms the earth. (Ref.2,3) 

When considerable ice melts in the Arctic due to global warming, CH4 trapped  in the ice is released and this combines with the CO2 to add to more global warming and the vicious cycle is repeated ( Ref.4)

The warming of the earth for the last 10,000 years has been about 1 degree Centigrade (C) but since green house gases stay in the atmosphere for a very long time, in the last fifty years we have seen almost another degree rise in C! Many countries have agreed not to go beyond the critical 2 degree C rise. But if we continue at the rate at which we are using fossil fuels, doing nothing, the rise could go up by 6 degrees C!! Scientists have shown with their climate models that at a 4 degree C rise , sea levels will rise by several feet, 40% of the earth will be uninhabitable leading to over millions of displaced people and several species will get extinct.( Ref.4)

 The terrible hurricane called Katrina in New Orleans, the horrible floods along the east coast due to Hurricane Sandy, the recent severe drought in California, the resulting forest fires and the recent flooding in North Carolina, plus the rapidly melting ice layers in the Arctic and the Antarctic regions can all be attributed to climate change. This is directly as a result of our fossil fuel culture and the consequent rise in carbon dioxide production. The melting of the ice and the displacement of animals like the polar bear were vividly illustrated in the documentary, “An inconvenient truth” publicized by Vice President Al Gore.(Ref.5) All these unusual weather patterns have caused movement of people from different regions:  New Orleans is a prime example, where the poor especially were not able to come back and are permanently displaced; a case of climate exiles.

Rising sea levels have been seen all over the world and small island countries  like Vanautu are showing alarming erosion of land and displacement  of peoples.Climate exiles will become a big problem if we do not address the problem of our heavy reliance on fossil fuel (Ref. 6 )

The reason we have not done much to counteract the use of fossil fuels by switching more to solar, wind power as alternative energy sources, is not difficult to comprehend. The tobacco lobby prevented the general public from knowing the hazards of smoking, and it took years of advocacy and presentation of evidence to connect lung cancer with smoking and change laws.  We have the fossil fuel industry today that campaigns vigorously  to deny climate change linkage with fossil fuel usage. We are encouraged to buy cars and not enough money is put into public transportation.(Ref. 7) In addition, there is pseudo-science to convince the public with false claims stating that climate change has nothing to do with fossil fuels (Ref.8) Several policy makers are beholden to fossil fuel companies and are not willing to legislate change. It  is not enough if a few countries lower their emissions, convert to alternative sources of energy ( solar, wind, waste) (Ref.7); many other countries that consume a lot of energy like the United States have to join in this venture.

The situation looks bleak here and we should be worried about the future of our planet earth. However, there are little rays of hope even here: Shell has decided not to drill in the Arctic, solar panels are back on the White House, and President Obama is definitely linking our dependence on fossil fuels with global warming/ climate change. But action is needed soon : it is needed now to respect the earth and the lives of future generations here.

Activities for Middle School Teachers:

Let students understand ppm by doing a serial dilution : starting with 1ml of  any food coloring agent added to 9ml  of water in a test-tube; taking 1ml of this solution to the next test-tube adding 9ml water, repeating this 4 more times. The 6th test-tube will be 1ppm of the food coloring.

Barbara KingSolver, a well-known writer and advocate for the well-being of the earth, wrote a  book about the demise of the monarch butterfly due to climate change and excessive herbicide use. The book is called,”Flight Behavior” (Ref.9). Students could learn about what happened to the monarch butterfly because of climate change. Many students with family in Michoacan, Mexico, might have heard stories about the migration of the monarch butterfly and the dwindling of the species.

Students could learn about ways to reduce their carbon footprint and calculate how much energy  they could save per month or per year.(Ref.10,11)

All the information given earlier about the possible devastation of the earth could make students and instructors depressed and feel helpless. Encourage students to look at courageous individuals like Dr Hansen (Ref.12) who has for years presented evidence at legislative hearings and has vowed to continue to fight against our energy choices. Bill McKibben, a long-time environmentalist with a global grass-roots movement, runs an organization called (that website has more information) to keep carbon emissions at or around 350 ppm. Let students also study what other countries in the world are doing for alternative sources of energy, look at India, Iceland, Norway,Peru, for example.(Look at second image where solar powers some signs in Tampa, Florida)

Learn about climate summits that have happened and will continue to happen every year in different countries.(Ref.13)

Nuggets of information:

Food transportation  in the United States is the largest single cause of carbon dioxide emissions.(Ref.7) Locally grown food consumed locally is more nutritious and less carbon energy intensive.

This July(2015) has been the hottest year since record-keeping began.(Ref.14)

Carbon footprint is the amount of carbon (carbon dioxide) each individual uses in a year.(Ref. 10)

The first reference to greenhouse effect because of the presence of gases was made in 1858 by John Tyndall. (Ref.15)

Jet or aviation fuel used for airplanes use higher alkanes from pentane all the way to 15 carbon alkanes, so you can imagine how much carbon dioxide is given off! There are some climate scientists who refuse to go anywhere by plane to avoid adding to the carbon footprint.

Climate scientists are seriously talking about the plight of climate exiles and which countries need to take them in when survival becomes impossible due to life-changing events like hurricanes, floods etc in their own homeland. I am proud to include my brother and sister-in-law’s articles here; they have been working tirelessly on climate change and social justice.(Ref.7,16,17)



2. Hein, Morris & Arena,Susan, Foundations of College Chemistry, (John Wiley and Sons, 2007)





7. Hillman, Mayer, Fawcett, Tina & Rajan, Sudhir Chella, The Suicidal Planet ( Thomas Dunne Books, /St.Martin’s Press, 2007)


9. Kingsolver, Barbara, Flight Behavior,(Harper/Harper Collins,2012)







2 Attachments16,17.

Preview attachment Byravan and Rajan (2010) – Ethical Implications SLR.pdf

Byravan and Rajan (2010) – Ethical Implications SLR.pdf

Preview attachment Byravan and Rajan (2015)-SLR and climate exiles-a possible solution.pdf

Byravan and Rajan (2015)-SLR and climate exiles-a possible solution.pdf
544 KB




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