Decarbonization is the systematic process of reducing carbon emissions, primarily carbon dioxide (CO2), across the global economy to achieve net-zero emissions. This means balancing the amount of greenhouse gases released with the amount that is removed. Reaching net-zero is necessary to mitigate the most severe effects of climate change, requiring a fundamental shift in how the world produces and consumes energy. This transition relies on deploying existing clean technologies at scale and developing new solutions across challenging sectors.
Transforming Electricity Generation
Clean electricity production is foundational for decarbonizing sectors like transport and industry. The immediate focus is on rapidly retiring power plants that burn fossil fuels, such as coal and natural gas, and replacing their capacity with low-carbon alternatives. Projections suggest that solar and wind power must be scaled up significantly this decade to stay on track for global climate goals.
Scaling intermittent sources requires modernization of the electrical grid infrastructure. The grid must become “smarter” and more resilient, able to manage power flowing from numerous, distributed sources rather than a few large, centralized plants. This includes upgrading transmission lines to efficiently transport vast amounts of renewable energy from remote generation sites to population centers.
Energy storage technologies provide a necessary buffer against the natural variability of the weather. Utility-scale lithium-ion battery systems absorb excess electricity generated during peak hours and release it when demand is high or generation is low. Longer-duration storage solutions, such as pumped hydro or emerging battery chemistries, are needed to ensure grid stability over days or weeks, maintaining a continuous, reliable supply.
To meet the projected growth in electricity demand from the electrification of other sectors, a diverse portfolio of firm, dispatchable power sources is required. Geothermal, hydro, and nuclear energy provide non-intermittent, low-carbon electricity that can stabilize the grid when weather-dependent sources are unavailable. This approach ensures the power system remains robust and supports the widespread adoption of electrification technologies.
Decarbonizing Mobility and Transport
The transportation sector is undergoing a split transition, addressing the needs of light-duty and heavy-duty vehicles. Passenger cars and light commercial vehicles are primarily shifting toward battery electric vehicles (EVs). This electrification pathway is directly supported by the transformation of the power grid, ensuring that the vehicles are charged with increasingly clean energy.
Conversely, the heavy-duty segments—including long-haul trucking, shipping, and aviation—present a greater challenge due to their high energy requirements and long distances. Battery technology remains impractical for many of these applications because of the weight and volume of batteries needed to achieve sufficient range. For these hard-to-electrify transport modes, the focus shifts to sustainable alternative fuels.
Green hydrogen and its derivatives are emerging as solutions for these heavy-duty applications. Green hydrogen, produced via electrolysis using renewable electricity, can be used directly in fuel cells for trucks, or converted into energy-dense fuels. These derivatives include green ammonia and green methanol for the shipping industry, which can be stored and handled more easily than pure hydrogen.
In aviation, Sustainable Aviation Fuel (SAF) can be blended with conventional jet fuel. A promising subset is e-kerosene, a synthetic fuel created by combining captured CO2 with green hydrogen. While these fuels still release CO2 upon combustion, the carbon is recycled, leading to a near-net-zero emissions profile over the fuel’s lifecycle.
Industrial and Infrastructure Solutions
Emissions come from “hard-to-abate” industries like cement, steel, and chemicals, which rely on high-heat fossil fuels or chemical processes that inherently release CO2. Decarbonization in these sectors requires a mix of material innovation and advanced technology deployment.
The production of cement and steel involves process emissions that are chemically unavoidable, not just from burning fuel. Heating limestone to produce cement clinker releases substantial CO2 from the raw material itself. This necessitates the use of Carbon Capture and Storage (CCS) or Carbon Capture and Utilization (CCU) technologies, which capture CO2 directly from smokestacks.
CCS permanently stores the captured CO2 deep underground in geological formations, while CCU converts it into valuable products like synthetic fuels or building materials. For the high temperatures required in steelmaking or glass furnaces, which can exceed 1,000°C, direct electrification is often technically challenging. Green hydrogen is being developed as a clean-burning substitute for natural gas, providing the necessary process heat without generating carbon emissions.
The deployment of these solutions requires constructing dedicated CO2 pipelines for transport to storage sites and significantly increasing electrolyzer capacity for green hydrogen production. Improving the efficiency of industrial processes and developing alternative materials, such as using different binders in cement, can reduce the overall reliance on energy-intensive steps.
Harnessing Natural Carbon Sinks
While reducing emissions at the source is the primary goal, net-zero requires actively removing legacy CO2 from the atmosphere. Natural carbon sinks, which leverage biological processes, provide a cost-effective and scalable method for this removal.
Reforestation and afforestation—planting new trees and restoring degraded forests—absorb CO2 through photosynthesis and store it in biomass and soil. Protecting existing ecosystems, particularly old-growth forests and coastal wetlands, is equally important because they hold vast carbon reservoirs. Integrating trees into farming systems can also enrich the soil and prevent erosion.
Beyond forests, soil carbon sequestration in agricultural lands offers a significant opportunity to draw down atmospheric carbon. Regenerative agriculture practices enhance soil health, increasing the amount of organic carbon stored beneath the surface. Techniques such as reduced tillage, which minimizes soil disturbance, and the use of cover crops prevent carbon from escaping back into the air.
Implementing intensive rotational grazing on pastureland increases soil carbon stocks. These improved land management strategies not only help climate mitigation efforts but also lead to more resilient, productive farming systems that can withstand environmental stresses like drought.