Carbon Catchers
Emission reduction is urgent as global warming and extreme weather events ravage the world. Reducing greenhouse gas emissions has become a consensus among humans. "Absorbing" and "locking" carbon dioxide from the atmosphere, preventing its release back into the air, has become another new endeavor alongside emission reduction.
Simpler in structure than humans, microalgae, single-celled organisms that have existed in oceans and rivers for millions of years, are natural carbon absorption experts. Microalgae, invisible to the naked eye, are a few micrometers in size and, like trees, rely on photosynthesis for survival. During photosynthesis, microalgae's chlorophyll converts carbon dioxide into proteins, carbohydrates, and fats while producing oxygen, thereby helping to reduce greenhouse gases in the atmosphere.
Young research teams in Hong Kong have set up demonstration sites to cultivate and breed microalgae in specially designed tanks. They have devoted great effort and explored various methods to enhance the carbon absorption capacity of microalgae, with the goal of industrializing microalgae cultivation and promoting it worldwide. Local innovation and technology companies have also commercialized the "carbon absorption experts" by installing fluorescent green "microalgae reactors" in schools and other locations. These reactors use air pumps to draw air into water-filled containers to cultivate microalgae, aligning with organizations' carbon reduction goals under ESG reporting.
Microalgae may be the "carbon absorbers," but their life cycle is short, and they gradually release carbon dioxide back into the atmosphere. Scientists in other fields continue to unleash their unlimited creativity by attempting to directly "absorb" carbon dioxide from the air. Some Western countries have already invested in the construction of large-scale facilities to capture atmospheric carbon dioxide and store it underground. In Hong Kong, researchers at universities have made preliminary developments in the "carbon dioxide reduction system," which converts carbon dioxide into raw materials for plastic chemicals. In the future, this system could potentially be applied in industrial projects to promote carbon neutrality.
Of course, tree planting remains a crucial strategy for "carbon sequestration" at present. Trees naturally reduce carbon dioxide through photosynthesis. Environmental organizations collaborate with universities to study five different types of forests in various locations in Hong Kong. By measuring plant data using instruments after selecting suitable locations, they estimate the "carbon storage" of Hong Kong's forests and their potential for carbon dioxide removal. The aim is to assist the government in formulating policies to enhance the carbon absorption capacity of forests, ensuring that forests continue to serve as a major force for "carbon sequestration" in nature.
The extent of microalgae's carbon absorption capacity is still under research. Trees can store carbon dioxide in trees and soil for long periods. Can microalgae have a similar "carbon sequestration" effect? How effective is machine-based carbon capture? These questions still require further exploration by the academic and environmental sectors.
