Reduce carbon dioxide in the air!

 

 

By Science Columnist Ho-Gwan Ko

 

 

Climate change is already happening. Even if we reduce carbon dioxide emissions with tremendous efforts, that alone is not enough as a large amount of carbon dioxide has already flowed into the atmosphere. We need to reduce carbon dioxide emissions and remove the gas already in the atmosphere at the same time to prevent impending disasters.

First, we can borrow the power of nature: plants. Plants get energy by converting carbon dioxide and water into oxygen and organic matter using light. Even when we’re doing nothing, plants reduce carbon dioxide in the atmosphere.

However, as people live in wider areas, forestry has decreased. Even now, people are destroying forests to create cities or agricultural land, or to use trees as resources. The Amazon rainforest, called “the lungs of the Earth,” is apparently losing the equivalent of a football field every minute. Conserving forests and creating new forests by planting trees in the wasteland will be of great help in reducing carbon dioxide in the atmosphere. The carbon stored in the tree is called green carbon.

In recent years, marine ecosystems are emerging as a new solution to prevent global warming. Trees whose roots are submerged in seawater such as mangrove trees and phytoplankton living in tidal flats turned out to be more effective carbon dioxide absorbers than rainforests. Tidal flats absorb four times more carbon dioxide by area than tropical rainforests, and mangrove forests six times more. If the coastal ecosystem is well preserved, we can combat climate change. The carbon stored in coastal ecosystems is called blue carbon.

Using the carbon stored in plants for energy is also helpful. Biofuels are made by fermenting grains such as beans and corn. When using fossil fuels like coal and oil, carbon buried in the ground is converted into carbon dioxide and released into the atmosphere. However, the carbon that comes out of biofuels used to be in the air and was stored in plants. Therefore, the theory is that the concentration of carbon dioxide in the atmosphere doesn’t increase.

The problem is that carbon dioxide in the air is not reduced. That is why we use “bio-energy with carbon capture and storage.” Carbon capture and storage is a method of collecting and trapping carbon dioxide generated when energy is used. In this way, we don’t need to release the gas back to the air after using the carbon, which plants absorbed from the atmosphere, as energy. As a result, the concentration of carbon dioxide in the atmosphere will be reduced.

 

▲ Carbon capture and storage technology is efficient for places that emit large amounts of carbon dioxide, including power plants.

 

Of course, it can also be applied to fossil fuel use. Although the amount of carbon dioxide in the atmosphere will not be decreased, we can at least prevent the gas from being released. Carbon capture and storage technology is used for places that emit large amounts of carbon dioxide, such as power plants. The collected carbon dioxide is stored deep underground in gas or solid form. However, this technology requires extra cautions because carbon dioxide can escape in the case of accidents such as earthquakes.

There are still problems to be solved. During the process of securing land and water for the crops used for biofuels, forests can be damaged or water resources can become scarce. It also may lead to the shortage of land for growing our food, causing food price spikes.

Research on technologies that directly remove carbon dioxide from the atmosphere is underway. This is not easy because carbon dioxide makes up merely 0.04% of the entire atmosphere. In fact, all solutions are not easy. However, just because it's difficult doesn't mean that we don't have to try. In order for us to live on the Earth for a long time, we must study and try every possible method.