Greenhouse Gases in America’s Garden

Carter D.
10th Grade, West Shore Jr/Sr High, Melbourne, Florida
Teacher: Tonya Galaida

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Abstract:
Experimentation was conducted to see if the effects of global warming on the atmospheric temperature and carbon dioxide levels in the next seventy years would inhibit C4 plant growth. A C4 plant is so maned because of the way that it incorporates carbon dioxide into a 4 carbon sugar before it is allowed to be used in the Calvin Cycle. It was hypothesized that if C4 plants grown in an environment without heightened temperature and carbon dioxide levels, then their biomass would be significantly greater than that of C4 plants grown in an environment without heightened carbon dioxide levels or temperature. A container was built that would allow for the temperature to be raised, and carbon dioxide to be added to the air to double the current concentration (to 720 ppm). Then C4 plants (Crabgrass) were allowed to grow in this environment, while being compared to other C4 plants grown without the added carbon dioxide and raised temperature. The the biomass of both the C4 plant groups was found and compared. After experimentation, it was found that the C4 plants grown in the altered environment had an increased biomass production, compared with the C4 plants grown in normal conditions. The scientist concluded that within the next seventy years, if the predicted atmospheric conditions occurred (heightened carbon dioxide level and temperature),m then the C4 plants would grow at an increased rate, compared with current growth rates. So, the United States agricultural market would not be negatively affected by global warming in the next seventy years. The hypothesis was supported by these results.

Problem:
Will the effects of global warming on the atmospheric temperature and carbon dioxide (CO₂) levels in the next seventy years inhibit C4 plant growth?

Hypothesis:
If C4 plants are allowed to grow in an environment with heightened temperature and CO₂ levels, then their biomass will be significantly greater than that of the C4 plants without heightened CO₂ and temperature.

Conclusion:
The results of the experimentation phase of this project show that if C4 plants are allowed to grow in an environment with a heightened carbon dioxide level and temperature, then their biomass is significantly greater than C4 plants grown in an environment with normal carbon dioxide concentrations and a lower temperature. The average biomass of samples of C4 plants grown in a heightened carbon dioxide and temperature environment was over three times the average biomass of samples of crabgrass grown in an environment with normal temperature and a normal carbon dioxide concentration (360 ppm).

So, in the same amount of time, four samples of C4 plants that were allowed to grow in an environment with a heightened temperature and carbon dioxide level, and their biomass production was significantly greater than those samples of C4 plants that grew in a normal environment.