Can We Reverse Global Warming By Turning Carbon Dioxide Back Into Coal?


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Fossil fuels like coal release harmful gases responsible for global warming (Credit: CSIRO/ CC-BY-3.0)

Carbon dioxide (CO2), released by activities like burning of fossil fuels such as coal, oil, and natural gas, is one of the biggest contributors to the greenhouse effect, responsible for global warming. Over the years, scientists have come up with several innovative solutions to capture the polluting gas. However, none have been practical enough to implement on a large scale. Now, researchers at RMIT University in Melbourne, Australia believe they may have finally found a feasible way to reduce atmospheric CO2 – turning the gas back into coal!

"While we can't literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock," said study co-author Dr. Torben Daeneke.

Greenhouse gases like carbon dioxide warm up the Earth's surface and oceans (Credit:

The idea of transforming CO2 into coal has been contemplated before. However, the metal catalysts - compounds that accelerate the chemical reactions - used to convert the gas into solid carbon only work at temperatures above 1,112 degrees Fahrenheit (600 degrees Celsius). In addition to being expensive, the high amount of energy needed for the conversion defeats the purpose of the exercise altogether. Additionally, the catalysts also tend to quickly clog from the carbon deposits, making them ineffective for long-term use.​​​​

To find a viable solution, the RMIT researchers began by creating a liquid catalyst - a mix of gallium, indium, and tin. To speed up the alloy's chemical reaction, the mixture was infused with catalytically-active cerium. The scientists than piped pure CO2 into the glass tube and zapped it with a jolt of electricity. The combination of the cerium and energy converted the gas into solid carbon, releasing only pure oxygen.

RMIT researchers found a way to transform CO2 to coal at room temperature (Credit: RMIT University/Nature Communications)

Additionally, the carbon flakes float away and settle along the sides and bottom of the liquid metal, leaving the cerium clog-free to continue its work. While the researchers, who published their findings in the journal Nature Communications on February 26, 2019, are not sure how the conversion happens, they suspect it's a multi-stage process, which involves the cerium reacting with oxygen, CO2, and water.

Bert Weckhuysen, a chemist at Utrecht University in the Netherlands, calls the study's results “novel” and “quite nice.” The researcher believes the carbon produced could be used to create materials for a variety of things, including battery electrodes, tennis rackets, and even airplane wings.

Whether the laboratory experiment can be replicated on a scale large enough to make a difference to our environment remains to be seen. But Dr. Dorna Esrafilzadeh, a doctoral fellow at RMIT University who spearheaded the research, is optimistic. The researcher says, “By using liquid metals as a catalyst, we’ve shown it’s possible to turn the gas back into carbon at room temperature, in a process that’s efficient and scalable. While more research needs to be done, it’s a crucial first step to delivering solid storage of carbon.”


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VocabularyPlay Game

acceleratecatalystsclogcontemplatedconversioncrucialfeasiblefossilgalliumgreenhouse effectimplementindiuminfusedjoltoptimisticpracticalreplicatedspearheadedtendtransforming 

Reading Comprehension (8 questions)

  1. Where does some of the excess carbon dioxide (CO2) in our atmosphere come from?
  2. Why is CO2 harmful for our environment?

Critical Thinking Challenge

Do you think researchers should be focusing more on finding ways to...


Vocabulary in Context

"The idea of transforming COinto coal has been contemplated before."

In the above sentence, the word contemplated most likely means:

(a) to consider...

  • ZeusFriday, March 8, 2019 at 8:10 am
    Amazing! (well, as long as it works correctly.)
    • Cool Friday, March 8, 2019 at 7:42 am
      Very interesting
      • willFriday, March 8, 2019 at 7:29 am
        Why ot go a little farther and turn the carbon into diamonds? Its done today on a very smal scale. the cost would be prohibitive.
        • sansFriday, March 8, 2019 at 7:24 am
          so cool
          • 22#Friday, March 8, 2019 at 7:21 am
            Very cool
            • jake_from_state
              jake_from_stateFriday, March 8, 2019 at 7:10 am
              wow i wish i wash this smart i can only get a job a state farm!!!! but this is cool bro!! i love the eath!!! NOTTTTTTTTT
              • RFriday, March 8, 2019 at 6:16 am
                Yes!!! I love to stop global warming!
                • typarmesean
                  typarmeseanFriday, March 8, 2019 at 6:08 am
                  that would be good
                  • spider-man1212
                    spider-man1212Friday, March 8, 2019 at 5:55 am
                    well lets hope this solves the global warming problem.
                    • ??? hfg dnfhFriday, March 8, 2019 at 5:12 am
                      Stop global warming!!!

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