Returning once again to the list of engineering challenges for the 21st century, the third challenge referenced by the National Academy of Engineering is the development of an effective method for the sequestration of carbon dioxide (Sequestering Carbon Dioxide).
As you no doubt know by now, Carbon Dioxide is considered one of the key perpetrators in the hazardous continuation of global warming, as increased carbon dioxide levels in the atmosphere have the ability to trap heat and UV rays in the atmosphere, leading to an increase in atmospheric temperatures that can endanger delicate ecosystems the world over (the Amazon, the arctic, etc).
The concept behind carbon dioxide sequestration is that, if we can find an effective way to trap carbon dioxide being produced by the burning of fossil fuels and other methods, and contain it such that it is not released into the atmosphere, we can inhibit the continued rise in average global temperatures and prevent further ecological damage.
Unlike some of the other engineering challenges on the list, the sequestration of carbon dioxide is not developed to the point of being very near a simple solution (obviously neither is fusion, but challenges like making solar energy affordable are much closer to realization). There are several methods proposed, but each of them presents a challenge of its own that will need to be overcome before any method can be implemented on a large scale.
The idea of trapping carbon dioxide by using the earth (or the earth beneath the oceans) as a sort of natural collection tank is an interesting one, and one that I am admittedly not as familiar with as other methods for reducing global warming. However, it seems obvious that if increased carbon dioxide is indeed one culprit in global warming, then stemming the continued flow of it from power plants, factories and the like is an absolute “must-take” step. The burning of fossil fuels (particularly coal for power, given its abundance and affordability at present) is not likely to be reduced or eliminated at any time in the near future. But if we can reduce the harmful environmental impact of such an activity, it will allow us to protect the environment and reverse some of the damage done while giving us the time to research and develop newer, cleaner methods that will someday replace fossil fuels.
As far as the carbon dioxide already present in the atmosphere (in much higher levels than previously), it will be essential that we reevaluate the status of areas like the rainforests. The natural process of photosynthesis is presently the easiest way to reduce carbon dioxide levels on a local scale, such as encouraging the planting of more trees or the development of more park areas. Ideally, the deforestation of rainforests could be stopped, but that may be easier said than done. However, reversing the damage to those ecosystems will be crucial in the near future, as the environment continues to change and threaten the safety of species or agricultural areas.
Follow up: A company called Skyonic claims to have developed a method of utilizing carbon dioxide from smokestacks to create baking soda, which could be used or buried as a storage method. Pretty interesting stuff, if it pans out. (Baking Soda Cure for Global Warming?)
