[Reading Science] Blue Chemistry: An Alternative Path for Responding to the Climate Crisis

Chemistry: From "Problem Industry" and Polluter to "Climate Solution Leader"
Scientific and Practical Solutions through Water, Carbon Dioxide, and Biological Replication

In an effort to overcome the climate crisis, humanity is turning its attention to "geoengineering," which involves directly manipulating Earth's systems, such as spraying aerosols into the stratosphere or dispersing iron into the oceans. While this approach promises rapid effects similar to surgical operations, it is controversial due to potential side effects, including changes in precipitation patterns, ecosystem disruption, and the risk of international conflict.

An alternative approach is "Blue Chemistry," which seeks to indirectly adjust the balance of the atmosphere and oceans through water and chemical reactions. If geoengineering is akin to radical surgery, Blue Chemistry is closer to a pharmaceutical prescription. Although slower, it aims to induce sustainable change by altering the underlying constitution. Of course, this approach is not free from uncertainty and risk either. Because chemical reactions can trigger abrupt changes if they reach critical thresholds, careful verification and social consensus are essential.

If geoengineering is a radical surgery, blue chemistry is closer to a pharmaceutical prescription. Although slower, it is an approach that aims to induce sustainable change by altering the constitution. Provided by Pixabay

Chemistry: From "Problem Industry" to "Climate Solution Leader"

Blue Chemistry is an idea that seeks to reposition chemistry-long stigmatized as a "problem-causing industry"-as a tool for environmental restoration. In a society where the word "chemical" has been synonymous with danger, there is now a movement to establish chemistry as a new agent of climate action. Two main currents underpin this shift. First, there is a social demand to change the negative perception of the chemical industry, which has been identified as a major source of carbon emissions and pollution. Second, there is a scientific reality that, amid the climate crisis-including water shortages and ocean acidification-problems cannot be solved without chemical solutions.

To this end, Blue Chemistry has first focused on "water." The climate crisis is directly linked to water scarcity. Glaciers in the Alps and Himalayas are rapidly shrinking, and regions that have relied on these as water sources now face severe conflicts. Rather than searching for new water sources, recycling existing resources and securing alternative supplies is a more practical solution.

This is where "reclaimed water" technology comes in. By treating sewage and wastewater to a high standard for reuse in agriculture or industry, Israel already meets more than 80% of its agricultural water needs with reclaimed water. In the Murcia region of southern Spain, treated urban wastewater supplies over 100 million cubic meters of reclaimed water annually to agriculture. In Orange County, California, the "Groundwater Replenishment System (GWRS)" project injects treated water back into underground aquifers, ensuring local water supply stability.

Chemistry as a Solution to the Water Crisis: Securing Quality Water at Low Cost and Energy

However, water issues are not just about securing supply; they also raise questions of justice, such as who uses more and who bears the costs. Large-scale industries and urban complexes can handle their own water treatment and recycling, but regions without such capacity must rely on public infrastructure.

Here, modular decentralized water treatment systems offer a solution. This approach involves industrial complexes and companies installing their own purification and recycling facilities, similar to having dedicated power plants in the energy sector. In Texas, for example, oil and chemical plant complexes are establishing their own supply systems with modular facilities. In Europe, food and beverage industry clusters are adopting modular systems to ensure stable water supply without overburdening local water networks.

This is where "chemistry" takes center stage. "Nanofiltration membranes" made from polymer composites and graphene significantly reduce energy consumption compared to traditional reverse osmosis methods and are being used in large-scale reclaimed water plants, such as Singapore's "NEWater" project. In the Netherlands and Switzerland, pilot projects are using zeolite catalysts to remove ammonium and heavy metals from water, while Japan has successfully used titanium dioxide photocatalysts to break down pharmaceutical residues. New adsorption technologies using materials such as metal-organic frameworks (MOFs) are also advancing rapidly, opening up new possibilities. Chemistry is thus being called back to the forefront of solving water challenges.

Carbon in the Air: Reborn as Building Materials and Chemical Feedstocks

The most fundamental cause of the climate crisis is the rising concentration of carbon dioxide (CO₂) in the atmosphere. The second pillar of Blue Chemistry is to absorb and convert this CO₂ through chemical reactions, transforming it into new resources.

There are two main approaches: "mineralization" and "organic chemical feedstock production." Mineralization involves promoting CO₂ absorption in seawater using alkaline minerals or injecting alkaline solutions produced by electrolysis into the ocean.

American startup Equatic is testing technology that creates alkaline substances via electrolysis before releasing them into the ocean, while Canada's Planetary Technologies is conducting pilot studies using byproducts from abandoned mines. Similar efforts are underway on land. U.S. startup CarbonCure injects CO₂ emitted during concrete production into building materials, increasing their strength and reducing greenhouse gas emissions. Blue Planet has used carbonate-based aggregates, produced by capturing CO₂ from power plants, in the construction of the new terminal at San Francisco Airport in 2016.

Another approach is to use CO₂ as a chemical feedstock. German chemical companies are synthesizing polyurethane from carbon dioxide to produce furniture and insulation materials, while an Icelandic company has commercialized technology that combines hydrogen and CO₂ to produce methanol. This trend is not simply about reducing emissions; it is creating a new industrial logic of "turning carbon into a resource." However, challenges remain in terms of cost, energy efficiency, and social acceptance.

Replicating the Evolution of Optimized Organisms through Chemistry

The third pillar of Blue Chemistry borrows chemical mechanisms developed through the evolution of living organisms to aid climate adaptation. Species that have survived billions of years of harsh environmental changes are optimized for their environments. Scientists are seeking to borrow the best evolutionary ideas from these species.

A representative example is the use of metabolic pathways from algae and bacteria. Microalgae absorb CO₂ through photosynthesis to synthesize polysaccharides and lipids. When combined with chemical processes, this enables both carbon sequestration and the production of biofuels and bioplastics. The U.S. Department of Energy (DOE) is supporting carbon sequestration projects using marine microalgae, and large-scale cultivation experiments are underway in Europe and Korea.

Similarly, the nitrogen fixation and metal reduction functions performed by soil bacteria are being combined with chemical catalysts to expand technologies for wastewater purification and pollutant stabilization. The Lawrence Berkeley National Laboratory in the United States has developed catalytic processes that mimic the metabolic pathways of metal-reducing bacteria, conducting research to stabilize uranium and cadmium in wastewater. By chemically replicating the efficiency proven by living organisms, energy consumption and carbon emissions are being reduced, yielding results essential for climate adaptation.

"Sustainability in Harmony with Nature Must Be Considered"

In this way, Blue Chemistry offers a new path for responding to the climate crisis through its three pillars: water, carbon, and biology.

Geoengineering serves as both a warning about "uncontrollable technology" and a question about whether we must artificially manipulate the planet to survive. Blue Chemistry provides a new answer to this question: instead of fighting against nature, we should understand its principles and harness its wisdom to coexist.

Water recycling and management, carbon dioxide resource conversion, and integrated biological and chemical approaches are all practical pathways for climate adaptation. In particular, Korea, which is surrounded by the sea on three sides and has a strong chemical and materials industry base, can play a leading role in this field. Lee Junghyun, a researcher at the Marine Biotechnology Research Center of the Korea Institute of Ocean Science and Technology, emphasized, "Blue Chemistry is a concept that combines chemistry and engineering with Earth's resources to create new products, and it can be a path toward a sustainable future. However, it is essential to prioritize the development of sustainable resources that can coexist with nature during research and industrial application."