November 14, 2025 | Renewables & Decarbonization
Limiting global warming to 1.5–2°C requires a rapid, coordinated transformation of energy systems across power generation, buildings, transport, and industry. The energy system currently accounts for roughly three-quarters of global greenhouse gas (GHG) emissions, with electricity and heat responsible for about 30%, transport for around 14%, manufacturing and construction for about 13%, and direct building energy use for about 7%.
This white paper synthesizes global evidence and models from the IPCC, IEA, IRENA and other leading institutions to describe technically and economically plausible decarbonization pathways across these four sectors. It is structured around a pathways framework developed by NEOS that distinguishes core technological options (electrification, renewables, low-carbon fuels, and carbon capture) and emphasizes the role of enabling conditions—such as grids, storage, smart digital systems, market design, and policy—alongside persistent constraints including cost, infrastructure lock-in, and social acceptance.
1. Introduction: From Climate Targets to Sectoral Transitions
The Paris Agreement commits countries to limiting global temperature rise to well below 2°C and pursuing efforts to stay below 1.5°C. The IPCC’s Special Report on 1.5°C shows that achieving this goal requires global CO₂ emissions to fall by roughly 45% from 2010 levels by 2030 and reach net zero around mid-century. The latest IEA Net Zero Roadmap reiterates that the global energy system must undergo an unprecedented transformation: emissions must fall steeply while energy access and economic growth continue, especially in emerging and developing economies.
The structure of energy demand means that decarbonization cannot be solved within a single sector. Electricity generation must shift away from unabated fossil fuels; buildings must drastically improve efficiency and move to low-carbon heating and cooling; transport must transition to zero- and low-emission vehicles and fuels; and industry—particularly steel, cement, chemicals and other energy-intensive subsectors—must adopt new processes, fuels, and carbon management solutions. At the same time, the system must remain reliable, affordable, and socially acceptable.
This paper adopts a sectoral approach, reflecting both global practice and the NEOS decarbonization pathways framework. It examines four pillars—power generation, buildings (electricity and heat), transport, and industry—and uses a common lens:
The analysis blends the NEOS framework—which sets out technologies, enablers, and constraints—with contemporary research and international experience.
2. Analytical Framework: Pathways, Enablers and Constraints
Across sectors, the fundamental levers of decarbonization can be grouped into four broad categories:
The NEOS framework also highlights cross-cutting enablers, which appear repeatedly in the sector tables: storage (batteries, pumped hydro, thermal and mechanical storage), smart grids and digitalization (sensors, smart meters, data analytics), demand management (dynamic tariffs, market signals, certificates of origin), incentives (feed-in tariffs, power purchase agreements, net metering), and decentralization of energy systems. At the same time, constraints such as grid congestion, bi-directional power flows, mineral supply risks, market dominance by incumbents, high upfront costs, and social acceptance challenges can slow or block implementation.
Figure: NEOS Framework – Decarbonization Pathways
In the sections that follow, this framework is applied to each sector, with attention to how technological choices, system design, and policy interventions interact.
3. Power Generation: From Fossil Dominance to Flexible, Renewable Systems
3.1 Current Role and Emissions
Electricity and heat production remains the single largest source of energy-related emissions, responsible for close to 30% of global GHG emissions. Despite rapid growth in renewable energy, fossil fuels—especially coal—remain deeply embedded in many power systems. The IPCC and IEA both conclude that unabated coal generation must be phased out rapidly by mid-century, and new coal projects without CCUS are incompatible with 1.5–2°C pathways.
At the same time, electricity is expected to become the central “backbone” of decarbonization, as transport, buildings, and industry increasingly electrify. This implies a substantial increase in electricity demand even as the sector decarbonizes.
3.2 Decarbonization Pathways in Power
The NEOS framework organizes power generation pathways around three main technology families: renewables, fossil fuels, and nuclear, with CCUS as a cross-cutting option.
A practical decarbonization strategy for power systems typically combines:
3.3 Enablers: Storage, Smart Grids, Demand Management, and Market Design
The NEOS framework emphasizes that decarbonized power systems require a suite of enablers beyond generation technologies.
3.4 Constraints: Grids, Net Load, and Mineral Supply
Decarbonization of power systems faces significant constraints, many of which are highlighted in the NEOS framework.
First, grid infrastructure often emerges as the bottleneck. Transmission and distribution networks were designed for one-way flows from large centralized plants to passive loads. High shares of variable renewables and distributed generation create bi-directional flows, congestion, and voltage control challenges. These issues can lead to curtailment of renewable output and undermine investment signals.
Second, the concept of “net load”—the difference between total demand and variable renewable generation—becomes central. Systems with high solar penetration experience pronounced “duck curves” where net load falls sharply during midday and ramps steeply in the evening. Managing net load requires flexible generation, storage, and responsive demand; failure to do so can compromise reliability and raise costs.
Third, critical minerals and supply chains present emerging risks. Technologies such as batteries, wind turbines, and solar panels depend on minerals including lithium, cobalt, nickel, and rare earths, raising concerns about geopolitical concentration, environmental and social impacts of mining, and recycling infrastructure.
Finally, policy uncertainty and market dominance by incumbent fossil-fuel generators can slow investment in new technologies. Ensuring transparent, stable regulatory frameworks and fair access to markets is essential for mobilizing private capital at scale.
4. Buildings: Electrification, Efficiency, and Clean Heat
4.1 Emissions and the Dual Role of Buildings
The buildings sector—encompassing residential, commercial, and public buildings—accounts for around one-third of global final energy consumption and over one-third of energy-related CO₂ emissions when indirect emissions from electricity are included. Building emissions arise from two main sources: (i) direct combustion of fossil fuels for space and water heating, cooking, and, in some regions, onsite power; and (ii) electricity use for cooling, appliances, lighting, and services, produced upstream in the power sector.
Because of this dual role, building decarbonization is both a demand-side and supply-side story. On the demand side, efficiency and better design reduce energy needs. On the supply side, electrification and modern heat networks enable clean energy to displace fossil fuels.
4.2 Decarbonization Pathways in Buildings
The NEOS framework emphasizes three main building decarbonization pathways: energy efficiency, electrification of heat, and increased use of renewable and low-carbon heat sources.
4.3 Enablers: Regulation, Subsidized Re-wiring, Digitalization
Building decarbonization depends heavily on policy and regulation, subsidized re-wiring, district heating, and digitalization.
4.4 Constraints: Cost, Split Incentives, and Acceptance
The NEOS framework highlights cost as the primary constraint in buildings.
Upfront investment for deep retrofits, heat pumps, or district heating connections can be substantial. Even when lifetime costs are lower, many households and small businesses are capital-constrained or sensitive to payback periods. Financial instruments—such as concessional loans, on-bill financing, and energy-service company (ESCO) models—can help bridge this gap.
A second constraint is the “split incentive” problem: building owners decide whether to invest, but tenants pay energy bills. Without appropriate regulatory mechanisms (e.g., minimum rental property standards) or innovative contracts, landlords may under-invest in efficiency and low-carbon technologies.
Third, social acceptance and awareness matter. The rapid rollout of heat pumps and other new technologies can be slowed by concerns about noise, aesthetics, or reliability, especially in historic or high-value buildings. Experience from, for example, UK churches adopting heat pumps shows that tailored engineering, stakeholder engagement, and communication about comfort and running cost benefits can significantly improve acceptance.
5. Transport: Electrification, Hydrogen, and Synthetic Fuels
5.1 Emissions Profile and Trends
Global CO₂ emissions from transport reached nearly 8 Gt, about 3% more than in the prior year, as aviation rebounded from the pandemic. Road transport alone accounts for roughly 12% of global emissions. Without strong policy intervention, transport demand growth would push emissions far above levels compatible with 1.5–2°C pathways.
5.2 Pathways by Mode
The NEOS framework differentiates road, rail, maritime, and air transport, and within road between light-duty vehicles and heavy-duty trucks and buses.
Different modes require distinct technological solutions.
Road transport – light-duty vehicles (LDVs)
Battery electric vehicles (EVs) are now the primary decarbonization pathway for cars and light vans. Global EV sales exceeded 17 million in 2024 and have continued to grow, accounting for 20% of car sales that year and a higher share since. Fuel cell vehicles using hydrogen and internal combustion engines running on low-carbon synthetic or biofuels may serve specific niches, but most net-zero scenarios rely on EVs to decarbonize LDVs.
Road transport – buses and trucks
For urban buses and short-haul trucks, battery electric drivetrains are increasingly cost-competitive, especially where charging can be centralized. For long-haul trucking, both battery electric and hydrogen fuel cell trucks are under development and deployment. Synthetic and sustainable biofuels may be used in existing fleets, but their availability is constrained and they are also needed in aviation and shipping.
Rail
Rail is relatively easy to decarbonize, as most new lines can be fully electrified and run on low-carbon electricity. Hydrogen or battery trains can substitute for diesel locomotives on non-electrified or remote lines where electrification is not economical.
Aviation
Aviation is one of the hardest sectors to decarbonize because of strict weight and energy density constraints. For short-range flights, hybrid-electric and fully electric aircraft, as well as hydrogen fuel cell concepts, are being piloted. For medium and long-haul aviation, the primary pathway relies on sustainable aviation fuels (SAF)—advanced biofuels and synthetic e-fuels produced from green hydrogen and captured CO₂. These fuels can be blended into existing jet fuel and used in current aircraft, but their cost and availability remain major challenges.
Maritime shipping
Shipping currently contributes about 3% of global GHG emissions but could rise to 5–8% by 2050 if left unchecked. Decarbonization will likely rely on a combination of green ammonia, e-methanol, biofuels, battery-electric ferries, and wind-assisted propulsion. Recent studies suggest that low-carbon fuels could reduce shipping emissions by over 70% by mid-century, especially if accompanied by carbon pricing and efficiency measures such as hull optimization and digital weather-routing.
5.3 Enablers: Policy, Charging Infrastructure, Smart Grids, and Market Signals
The NEOS slide underscores several transport enablers: policy and regulation, R&D, charging infrastructure, smart grids and digitalization, market signals, and retail competition.
5.4 Constraints: Grids, Minerals, and Cost
The main constraints identified in the NEOS framework are grid capacity, critical minerals, and cost.
Large-scale EV adoption increases power demand and can overload local distribution networks if charging is unmanaged. Reinforcing networks, deploying smart chargers, and incentivizing off-peak charging can mitigate this, but require capital and careful planning.
Battery and motor technologies depend on critical minerals, raising concerns about supply security, environmental impacts, and labour conditions. This calls for diversified supply chains, improved recycling, and research into alternative chemistries with lower critical mineral intensity.
Finally, while the total cost of ownership of EVs is falling and can already be lower than internal combustion engine vehicles in many segments, upfront purchase costs and lack of financing options remain barriers for many consumers, especially in lower-income markets. Similar cost issues arise for hydrogen trucks, SAF, and green shipping fuels, which are currently substantially more expensive than fossil alternatives.
6. Industry: Clean Heat, Process Redesign, and Carbon Capture
6.1 Industrial Emissions and Hard-to-Abate Sectors
Industry—including steel, cement, chemicals, refining, and other manufacturing—is responsible for a large share of global emissions. The World Economic Forum’s Net-Zero Industry Tracker highlights that many industrial processes require high-temperature heat above 500°C, making direct electrification technically challenging with today’s commercial technologies. For example, high-temperature heat represents about 83% of energy use in steel and 45% in cement.
Cement alone is responsible for 7–8% of global CO₂ emissions, driven by both fuel combustion and process emissions from the calcination of limestone. Demand for cement and steel is expected to grow, particularly in the Global South, which complicates decarbonization.
6.2 Decarbonization Pathways in Industry
The NEOS framework groups industrial pathways into electrification, alternative heat and fuels, process redesign and alternative feedstocks, and fossil fuels with CCUS.
6.3 Enablers and Constraints
The NEOS framework lists policy and regulation, incentives, R&D, and grid investment as critical enablers, with cost, waste management, and social acceptance as key constraints.
Industrial decarbonization in practice requires:
Cost remains the central constraint. Early projects can be significantly more expensive than conventional technologies, and cost pass-through to consumers is often politically sensitive. Waste management and material supply issues—such as sourcing sustainable biomass, ensuring responsible mining of critical minerals, and managing new waste streams like used hydrogen infrastructure—also pose challenges. In addition, social acceptance is crucial where industrial transitions are linked to employment and regional development; poorly managed transitions can trigger resistance from communities and workers.
7. Cross-Cutting Enablers and Constraints
Across all four sectors, several cross-cutting enablers emerge:
Major constraints cutting across sectors include:
Addressing these constraints requires not only technology and capital, but also institutional reform, capacity building, and sustained stakeholder engagement.
8. Implications for Utilities, Policymakers, and Investors
For utilities and system operators, the transition implies a fundamental shift in business models—from selling kilowatt-hours produced in centralized plants to orchestrating complex systems of distributed generation, flexible demand, and new energy services. Investments in grid modernization, storage, and advanced analytics are no longer optional but central to core business strategy.
For policymakers and regulators, the findings underscore the importance of integrated planning across sectors. Electrification in buildings, transport, and industry will significantly increase electricity demand and change load profiles; these changes must be anticipated in power system plans and distribution network investment decisions. Clear regulatory frameworks for new assets like EV charging networks, hydrogen pipelines, and CO₂ transport and storage infrastructure are essential.
For investors and financial institutions, decarbonization pathways define both risks and opportunities. Stranded asset risk is rising for unabated coal, oil-fired power, and inefficient industrial facilities, while renewed demand is emerging for low-carbon infrastructure and technology providers. Incorporating sector-specific transition pathways into portfolio strategies will be central to managing climate-related financial risk.
Advisory firms such as NEOS can play a bridging role by translating global pathways and best practices into context-specific roadmaps, advising clients on regulatory design, investment prioritization, and implementation strategies, and helping to design projects that align technical feasibility, financial viability, and social acceptance.
9. Conclusion
Decarbonizing power generation, buildings, transport, and industry is both a technological and institutional challenge. No single solution is sufficient; rather, the transition will be driven by a portfolio of measures: rapid deployment of renewables and storage; deep efficiency improvements; electrification of end-uses; deployment of hydrogen, sustainable bioenergy, and synthetic fuels where appropriate; and strategic use of CCUS in hard-to-abate applications.
The NEOS decarbonization pathways framework, with its emphasis on sector-specific technologies, enablers, and constraints, offers a practical structure for decision-makers who must navigate this complexity.
Global evidence from the IPCC, IEA, and other institutions confirms that these pathways are technically feasible and, in many cases, economically advantageous, particularly when the co-benefits of cleaner air, improved health, and reduced fuel import dependence are accounted for.
Yet the pace and shape of the transition will be determined not only by technology and economics, but also by governance, policy, and societal choices. Countries, cities, and companies that move early to align their power, buildings, transport, and industrial systems with net-zero trajectories will be better positioned to capture the economic opportunities of the transition and to contribute meaningfully to global climate goals.
This white paper is intended as an analytical foundation for such efforts. It can be further tailored to specific national or regional contexts, including the Middle East, Africa, and Central Asia, where NEOS and its partners are actively engaged in designing and implementing decarbonization strategies.