From carbon capture to renewable energy, chemistry provides critical solutions for mitigating climate change impacts

Climate change is one of the most pressing global issues today. It is primarily driven by human activities, particularly the burning of fossil fuels, deforestation, and industrial processes, which increase the concentration of greenhouse gases in the atmosphere. These gases trap heat, leading to a rise in global temperatures, melting ice caps, rising sea levels, and more extreme weather events such as heat waves, hurricanes, and floods.

The impacts of climate change are widespread and affect ecosystems, biodiversity, human health, and economies. Vulnerable communities, particularly those in low-lying coastal areas, are already experiencing severe consequences. Additionally, food security is threatened as changing weather patterns disrupt agriculture.

While the scale of the problem can seem overwhelming, chemistry is playing a critical role in developing solutions that could help mitigate the effects of climate change. From capturing carbon dioxide to developing renewable energy sources, chemists are at the forefront of the fight against global warming.

Climate change represents one of the most significant challenges facing humanity today. The rapid increase in greenhouse gases like carbon dioxide (CO₂) and methane (CH₄) due to human activities has led to rising global temperatures, shifting weather patterns, and devastating impacts on ecosystems and communities. While the problem is complex, chemistry is providing innovative solutions that could mitigate these effects and pave the way toward a sustainable future. From carbon capture to renewable energy, chemistry is at the forefront of efforts to combat climate change.

Carbon Capture and Storage (CCS)

Carbon Capture and Storage (CCS) is a critical technology aimed at reducing CO₂ emissions from major industrial sources such as power plants, steel mills, and cement factories. CCS involves three key steps: capturing CO₂ from emissions, transporting it, and securely storing it underground.

1. Capture Techniques: The most common method for capturing CO₂is post-combustion capture, where CO₂is removed from the exhaust gases of power plants. Chemical absorbents, such as amines, selectively bind to CO₂ and separate it from other gases. Other techniques include pre-combustion capture, which removes CO₂ before fuel is burned, and oxy-fuel combustion, where fuel is burned in pure oxygen, resulting in a flue gas rich in CO₂ that is easier to capture.
2. Transport: Once captured, CO₂is compressed into a liquid-like state and transported via pipelines to storage sites. Pipelines for CO₂transport are similar to those used for oil and gas, but with additional safety measures to prevent leaks.
3. Storage: The captured CO₂is injected into deep geological formations, such as depleted oil and gas fields or saline aquifers, where it can be stored for thousands of years. Scientists use a combination of geological surveys, computer modelling, and monitoring to ensure that the CO₂remains securely trapped.

Recent advancements in CCS technology have focused on reducing costs and improving efficiency. For example, researchers are developing new materials like metal-organic frameworks (MOFs) and ionic liquids that can capture CO₂ more selectively and efficiently than traditional amines. These innovations are crucial for scaling up CCS to the level needed to make a significant impact on global emissions.

Direct Air Capture (DAC)

While CCS targets emissions from industrial sources, Direct Air Capture (DAC) focuses on removing CO₂ directly from the atmosphere. This technology could be essential for achieving net-zero emissions by addressing not just current emissions but also the excess CO₂ already in the air.

1. How DAC Works: DAC systems use large fans to draw in ambient air, which then passes through a filter containing chemical sorbents that capture CO₂. The CO₂is then released from the sorbents by applying heat or pressure and can be stored underground or used in industrial processes.
2. Applications: One of the key advantages of DAC is its versatility. Unlike CCS, which is tied to specific emission sources, DAC can be deployed anywhere, making it possible to target regions with high atmospheric CO₂levels. Additionally, the captured CO₂can be used to produce carbon-neutral fuels, which could help decarbonise sectors like aviation and shipping, where direct electrification is challenging.
3. Challenges: The main challenge for DAC is its high energy and cost requirements. However, advances in materials science are driving down these costs. For example, researchers are developing new sorbents that require less energy to regenerate, as well as integrating DAC with renewable energy sources to reduce its carbon footprint.

Renewable Energy: The Chemistry of Batteries and Solar Cells

Renewable energy is central to reducing our reliance on fossil fuels, and chemistry plays a vital role in advancing these technologies.

1. Solar Cells: Photovoltaic (PV) cells convert sunlight directly into electricity, and advances in materials chemistry are improving their efficiency and affordability. Traditional silicon-based solar cells are now being supplemented by new materials like perovskites, which are cheaper and easier to produce. Perovskite solar cells have rapidly achieved efficiencies comparable to silicon and can be manufactured using low-energy processes like printing.

– Hybrid Tandem Cells: Researchers are combining perovskite and silicon in hybrid tandem cells to achieve even higher efficiencies. These cells capture a broader spectrum of sunlight, converting more of it into electricity, and could become a game-changer in the solar industry.

– Organic Photovoltaics (OPVs): Another area of research is organic photovoltaics, which uses carbon-based materials to create lightweight, flexible solar cells. OPVs are less efficient than traditional cells but offer advantages in terms of cost and versatility, making them ideal for applications like wearable electronics and building-integrated photovoltaics.

2. Batteries: Energy storage is crucial for balancing the supply and demand of renewable energy, and advances in battery chemistry are enabling this transition.

– Lithium-Ion Batteries: The widespread adoption of lithium-ion batteries has driven the growth of electric vehicles (EVs) and renewable energy storage. Researchers are now focusing on improving energy density, charging speed, and safety. One approach is to replace the graphite anode in lithium-ion batteries with silicon, which can store more lithium ions and thus increase the battery’s capacity.

– Solid-State Batteries: Solid-state batteries, which use a solid electrolyte instead of a liquid one, promise to offer higher energy density and improved safety. These batteries are less prone to overheating and could extend the range of EVs while reducing charging times.

– Beyond Lithium: In addition to improving lithium-ion technology, scientists are exploring alternatives like sodium-ion and zinc-air batteries, which use more abundant and less expensive materials. These technologies could provide low-cost energy storage solutions for grid applications, helping to stabilize renewable energy supply.

Green Chemistry: Designing Sustainable Products and Processes

Green chemistry seeks to reduce the environmental impact of chemical manufacturing by designing products and processes that minimize waste, energy use, and hazardous substances.

1. Biodegradable Plastics: Traditional plastics are derived from petroleum and can take centuries to degrade, contributing to the global plastic pollution crisis. Chemists are developing biodegradable plastics made from renewable resources like corn starch or cellulose. These materials break down more quickly and are less harmful to the environment. For example, polylactic acid (PLA) is a biodegradable plastic used in packaging, disposable tableware, and even medical implants.
2. Catalysis: Catalysts are substances that speed up chemical reactions without being consumed in the process. Green chemistry emphasizes the use of efficient, non-toxic catalysts to reduce energy consumption and waste in chemical manufacturing. One area of focus is the development of catalysts for the conversion of CO₂into valuable chemicals, such as methanol, which can be used as a fuel or feedstock for other industrial processes.
3. Solvent-Free Processes: Traditional chemical processes often rely on large quantities of organic solvents, which can be harmful to both health and the environment. Green chemistry promotes the development of solvent-free or water-based processes, which reduce the need for hazardous chemicals and the energy required for solvent recovery. This approach is being applied in the production of pharmaceuticals, agrochemicals, and other high-value products.

Chemistry in Agriculture: Reducing Emissions and Enhancing Carbon Sequestration

Agriculture is responsible for about 10% of global greenhouse gas emissions, primarily from methane released by livestock and nitrous oxide from fertilized soils. Chemistry offers solutions to reduce these emissions and enhance carbon sequestration.

1. Smart Fertilizers: Traditional nitrogen fertilizers can lead to the release of nitrous oxide, a greenhouse gas with 300 times the warming potential of CO₂. Chemists are developing “smart” fertilizers that release nutrients more slowly and in response to plant needs, reducing the amount of nitrogen lost to the atmosphere. These fertilizers can improve crop yields while reducing their environmental impact.
2. Soil Carbon Sequestration: Enhancing the ability of soils to store carbon is a promising strategy for mitigating climate change. Practices like adding biochar (a stable form of carbon-rich material produced from organic waste) to soils can increase carbon storage and improve soil health. Chemists are also studying how different soil amendments, such as mineral additives, can enhance carbon sequestration and reduce emissions from agricultural lands.
3. Methane Reduction: Livestock produce methane during digestion, contributing significantly to agricultural emissions. Feed additives that inhibit methane-producing microbes in the stomachs of cattle are being developed to reduce these emissions. For example, 3-nitrooxypropanol is an additive that has been shown to reduce methane emissions from cattle by up to 30%.

The Future of Climate Chemistry: Challenges and Opportunities

While the contributions of chemistry to climate change mitigation are promising, several challenges must be addressed to fully realize their potential:

1. Scaling Up Technologies: Many of the technologies discussed, such as CCS, DAC, and advanced batteries, are still in the early stages of development or deployment. Scaling them up to the level required to make a global impact will require significant investment, infrastructure development, and international collaboration.
2. Cost and Economics: Reducing the costs of these technologies is crucial for their widespread adoption. Economies of scale, continued research, and supportive policies, such as carbon pricing or subsidies for clean technology, will be essential in driving down costs and making these solutions economically viable.
3. Public Acceptance and Policy Support: The success of these technologies also depends on public acceptance and strong policy support. Educating the public about the benefits of these innovations and ensuring that policies align with climate goals will be key to their successful implementation.

Conclusion Chemistry is not just a science but a powerful tool in the fight against climate change. By developing technologies to capture carbon, harness renewable energy, and create sustainable products, chemists are helping to address the root causes.

The writer is a Chemistry teacher at Crescent Public School Naseem Bagh

Khursheed Ahmed Reshie