Solutions Document, JA

Solutions

            Since direct absorption of carbon dioxide is the primary cause of ocean acidification, reducing the amount of CO₂ in the atmosphere would have the greatest effect of reduction of it. A large-scale solution is the use of CO₂ scrubbers, towers that absorb CO₂ from the air. Air with CO₂ enters a first tower that contains gaseous solvents, usually ammonia, and is cooled. The ammonia absorbs the CO₂ from the air, thereby isolating it. The remaining air is now cleaner and returned to the atmosphere. The cooled CO₂ is moved to another tower or another chamber and is heated. The CO₂ and ammonia separate and the CO₂ is drawn out and pumped into storage containers. The ammonia is recycled back to the first tower to be used again. This process is relatively new and is still being trialed and tested, but it has great potential. Currently, it costs $150 to remove one ton of CO₂ using carbon scrubbing, which would add 4-9 cents/kilowatt to an individual’s energy bill. In time, this cost is sure to come down as technology improves. The towers would be placed on factories or power plants, where much of the CO₂ is produced. The CO₂ that has been removed from the air can be used for useful purposes. The gas can be pumped underground into almost depleted oil reserves. The CO₂ helps dislodge the oil so that all of it can be extracted from the ground. Carbon scrubbing can remove 80-90% of released CO₂ from the atmosphere.

            A second solution is the addition of calcium carbonate to coastal waters. This solution more directly solves ocean acidification. Calcium carbonate is the mineral that marine organisms such as coral, crabs, and shellfish use to make their exoskeletons. Ocean acidification inhibits their ability to use calcium carbonate to do so. By adding extra calcium carbonate to the water, it can offset the increased CO₂ and balance marine ecosystems. The extra calcium carbonate absorbs the CO₂ so that organisms can use the natural amounts for exoskeleton growth. This solution would be most effective in coastal regions where ocean acidification is highest and where the added calcium carbonate could be most effective. The addition of this mineral may be a concern for environmentalists and tourists visiting the area. They may not be too keen on adding more to the ocean.