Abstract
Climate initiatives, fossil fuel use and subsidies remain entrenched, locking in decades of emissions. The years 2020–2024 illustrate this tension vividly, with record emissions rebounding post-pandemic alongside record renewable deployments. Natural carbon sinks, once absorbing nearly half of human emissions, are weakening, amplifying urgency. Sectoral contributions remain dominated by power, industry and transport, while policy gaps persist between ambitious net-zero pledges and weak implementation. Emerging solutions—solar, wind, battery storage, green hydrogen, CO₂ valorisation and carbon capture—show promise but require rapid scaling, systemic integration and equitable transition frameworks. Achieving climate stability will demand not just a net-zero but a net-negative trajectory, where CO₂ is transformed into valuable fuels, chemicals and materials. The decisive decade to 2030 offers a narrowing but critical window: choices made now will determine whether humanity secures a sustainable, resilient and just energy future.
Introduction
Energy and environment are intimately connected and particularly the use of fossil sources for the production of various hydrocarbons and fuels have led to massive emissions of carbon dioxide, a greenhouse gas (GHG). Since 1750,
when the CO2 concentration in the atmosphere was around 280 ppm, with the advent of petroleum refineries and coal based power plants, the emissions increased substantially leading to rise of atmospheric temperature and climate change.
Due to industrialisation and massive increase in transport, more carbon based fuels have been consumed. The critical technological challenge of this century is thus securing a continuous supply of energy, amid rapidly escalating global demand, while decisively transitioning away from carbon-intensive fossil fuels to curb GHG, particularly CO₂. The years 2020 to 2024 encapsulate this dual struggle vividly. Emissions plummeted in 2020 amid global lockdowns due to the COVID 19 pandemic, rebounded in 2021 and then forged new records: the fossil CO2 was ~36.6 Gt (2022), ~37.4 Gt (2023) and ~37.8 Gt (2024). Although economic growth outpaced emissions growth in 2024, atmospheric CO₂ concentrations still surged to ~424 not reversed, the upward trend; the carbon economy remains resilient, demanding far more rapid, systemic shifts.
Systemic Impacts of the Energy Transition
The energy transition is not only about substitut-ing fossil fuels with renewables but also about recon-figuring the very structure of global economies and societies. It affects labour markets through the decline of fossil fuel dependent industries and the growth of renewable energy jobs, reshapes consumer behaviour via electrification and efficiency, and requires new institutional frameworks for governance and finance. Moreover, it intersects with globalisation, technologi-cal innovation and socio-economic development, mak-ing electricity systems a key barometer of progress. Countries that succeed in modernising their power grids, scaling up energy storage and fostering green industrial policy are likely to emerge as leaders in the new energy economy. Those that lag may face risks to competitiveness, energy security and long-term resil-ience.
One bold idea is the creation of a universal or interconnected global grid, for example, operating at a standardised voltage (such as 1100 V) and enabling near 24×7 renewable power supply by linking solar-rich and other renewable-rich regions across countries. Such transnational grid integration could balance time-zone differences, reduce intermittency and improve global energy access.
While initiatives like the International Solar Alliance (ISA) and the “One Sun, One World, One Grid” (OSOWOG) vision (championed by India and supported at COP26) touch upon this concept, it was not formally part of the Paris Agreement (2015). The Paris Agreement focused mainly on emissions reduction commitments (NDCs), climate finance, adaptation and transparency mechanisms, not on global grid standardisation
Policy Urgency and the Decisive Decade
Taken together, the science makes clear that the next 5 – 10 years will be decisive in determining the trajectory of the planet’s climate system. Failure to implement immediate, large-scale reductions risks locking the world into a pathway of dangerous warming with irreversible consequences for ecosystems, economies and human well-being. Stronger policies, ranging from carbon pricing and subsidy reform to accelerated renewable deployment, resilient infrastructure and just transition frameworks, are essential to bridge the gap between ambition and action. The window is rapidly narrowing, but decisive choices made this decade can still ensure a liveable future (IPCC; UNEP).
Renewable Energy Technologies: Evidence from Science and Sector Studies
Solar PV: Over the past decade, utility-scale and distributed solar PV have achieved dramatic cost and performance gains. Technological learning, economies of scale and supply-chain optimisation have driven down levelised costs of electricity (LCOEs) to levels comparable with or cheaper than, the most competitive new fossil fuel plants across many regions (IEA). Modern silicon-based modules now routinely achieve lifetimes of 25 years or more. Recycling and circular-economy pathways are advancing, including recovery of silicon, glass and critical metals, though large-scale collection systems and supportive end-of-life policies remain under development.
Wind (onshore and offshore): Innovations in rotor design, segmented blades, advanced control systems and taller towers have increased turbine efficiency and project flexibility. Low-specific-power turbines with hub heights exceeding 100 m can capture stronger, steadier winds, raising capacity factors and reducing costs per MWh. Offshore wind, in particular, is ben-efiting from larger turbines, floating foundations and better siting practices, which are unlocking significant new resource potential (ATB; Energy Technologies Area). Newer designs combining both solar and wind power have been advanced to improve economics as well as space. Apparently about 15% of power is con-tinuously produced through the wind blades and the remaining by solar.
Hydropower: Large-scale hydro remains the world’s most important dispatchable renewable, offer-ing seasonal storage, grid inertia and balancing ser-vices. However, its output is increasingly sensitive to hydrological variability, with droughts and reduced reservoir inflows lowering generation in key produc-ing countries. Pumped hydropower continues to pro-vide the most cost-effective long-duration storage solu-tion, but integrated water–energy planning is needed to secure its role in a changing climate (IEA).
Nuclear Energy: Nuclear energy is indeed a low-carbon source, producing very little CO₂ during electricity generation. It plays a critical role in many countries’ efforts to decarbonise the power sector. One of the current technological trends is the growing interest in Small Modular Reactors (SMRs), which promise faster deployment, lower upfront costs and suitability for remote or difficult-to-serve areas. France remains a world leader in nuclear energy. It has about 56 operable reactors with a combined installed
capacity of ~61.4 GW electric as of end-2022. Its nuclear plants supplied approximately 62-63% of its electricity in 2022 and recent figures for 2024 show a share closer to 67-70% of power generation coming from nuclear sources. India has set ambitious goals: the government aims to reach 100 GW of nuclear power capacity by 2047 under its newly announced Nuclear Energy Mission. As of April 2025, India’s current installed nuclear capacity is about 8.8 GW, with roughly 6.6 GW under construction and about 8 GW more in planning phase, which suggests steady progress but also a long way to go to hit the 100 GW target. The plan includes launching five indigenously developed SMRs by 2033, with a research and development budget of about Rs 20,000 crore (~US$2.4-3 billion) allocated for that purpose.
Biomass and Biogas: Sustainably sourced biomass and upgraded biogas (biomethane) can provide dispatchable renewable power, industrial heat and feedstocks while closing nutrient and carbon cycles. The climate benefits depend heavily on feedstock type, land-use impacts and system boundaries. Studies emphasise prioritising waste and residue streams over dedicated energy crops to maximise life-cycle GHG reductions and avoid competition with food systems. Food waste and agricultural biomass for producing GH2 and bio-CNG are being studied widely.
Geothermal and niche Renewable Energy Systems (RES): Geothermal power and concentrated solar power (CSP) offer firm, low-carbon electricity and process heat in regions with suitable geology or solar resources. Although their deployment is geographically constrained, these technologies are strategically valuable for decarbonising heavy industry and heating systems (IEA). ONGC Energy Centre (OEC) has proposed a geothermal plant in the Ladakh region. Drilling operations for the Puga Valley geothermal pilot (1 MW) have resumed after a hiatus to upgrade equipment, with two wells planned (~1,000 m depth) in search of temperatures above 200 °C and the project is nearing completion of its first geothermal well.
Technical Challenges and System Integration
A major technical challenge is the intermittency of variable renewables such as wind and solar. Ensuring system reliability requires a diversified portfolio: short-duration batteries for diurnal balancing, long-duration storage solutions such as pumped hydro, hydrogen or thermal storage for seasonal shifts, demand-response mechanisms and advanced digital grid controls. Cross
-border interconnections further reduce variability by pooling geographically diverse resources. Some published reviews and IEA analyses highlight that the most cost-effective near-term strategy combines batteries, smart grids and flexible generation, with hydrogen and other long-duration technologies scaling up in the 2030s (IEA).
Energy Security, Resilience and Social Dimensions
Decentralisation and resilience: Distributed renew-ables such as rooftop solar, community microgrids and behind-the-meter storage enhance resilience by reducing single points of failure and import dependencies. Microgrids can operate independently during disturbances, maintaining essential services, while aggregations of distributed energy resources increasingly provide ancillary grid services like frequency control and black-start capabilities (IEA).
The Government of India’s policy to install 10 million rooftop solar systems is a transformative step. By connecting household-generated solar power to the central grid, ordinary citizens can actively participate in the clean energy transition while also earning additional income from surplus electricity.
To fully realise this vision, however, the capacity and flexibility of the power grid must be substantially enhanced. At present, states such as Maharashtra allow solar producers to supply power to the state grid only during limited time windows. This creates a major bottleneck and results in significant losses, both for households and for the renewable energy ecosystem as a whole.
Several policy measures can help overcome this challenge. First, households should be encouraged to pair rooftop solar with battery storage, so that excess energy generated during the day can be stored and supplied to the grid during peak evening demand. Second, utilities should adopt dynamic tariffs, where households receive higher payments for exporting electricity at times of greatest demand rather than only during the daytime. Third, power generated by multiple households can be aggregated into regional pools or “virtual power plants,” allowing small producers to participate collectively in state and national electricity markets.
In parallel, there is a need for significant investm-ent in upgrading transmission and distribution infrastructure to handle two-way flows of electricity. Smart grids and digital monitoring systems can further strengthen stability by managing fluctuations in real time. In addition, utilities could offer long-term purchase agreements to households, similar to power purchase agreements (PPAs) for large solar projects, ensuring both stable incomes for producers and predictable supply for the grid. Finally, rooftop solar must be integrated with national initiatives such as the “One Sun, One World, One Grid” vision and India’s green hydrogen mission, so that surplus power can also support energy storage, electric vehicle charging and hydrogen production.
Together, these measures would enable rooftop solar to go beyond reducing household electricity bills. It would transform citizens into active “prosumers” both producers and consumers of clean energy, while creating a more democratic, resilient and sustainable energy economy for India.
Cross-border cooperation: Regional integration through interconnectors and market coupling smooths renewable variability by leveraging geographic dive-rsity; for example, southern solar, northern hydro and western wind resources in Europe. Studies show that coordinated pan-regional transmission and market design significantly reduce system costs and curtailment at high renewable penetrations (IEA).
Just and inclusive transition: The success of the energy transition depends not only on technologies but also on governance, equity and socio-economic policy. Literature stresses the importance of reskilling workers, supporting fossil fuel dependent regions and ensuring universal access to affordable clean energy. Social safeguards and inclusive financing are essential to prevent dislocation and to ensure that the benefits of transition are broadly shared (IEA).
Employment and Economic Benefits
Renewable energy has become a major source of global employment and economic growth. Recent assessments by IRENA, ILO and REN21 estimate that the sector supports between 13–16 million direct and indirect jobs, depending on methodology and year, with solar PV, bioenergy and hydropower accounting for the largest shares (IRENA 2023; ILO 2022; REN21 2023). Employment is distributed across the value chain — from design and engineering to manufacturing, construction, operations and maintenance (O&M), and recycling. Importantly, these jobs tend to be more geographically anchored than fossil fuel jobs, generat-ing stable local value while reducing exposure to vola-tile global commodity markets. Domestic supply-chain development, local content requirements and targeted workforce training amplify the economic multiplier of renewable investments (ILO 2022; REN21 2023).
Job Creation Dynamics
Solar PV and onshore wind installations generate a higher number of construction and installation jobs per megawatt compared with centralised fossil-based plants. Manufacturing hubs for modules, inverters and turbine components can concentrate employment regionally, but also open export opportunities. Investment in renewables stimulates parallel growth in manufacturing, O&M and grid infrastructure upgrades. Empirical modelling suggests that every US$1 billion invested in renewable energy yields higher GDP and employment than an equivalent investment in fossil fuels, as shown in multiple IEA and IRENA case studies (IEA 2022; IRENA 2023).
Green Hydrogen and Industrial Decarbonisation
Green hydrogen, produced via electrolysis pow-ered by renewable electricity, is widely seen as essen-tial for decarbonising hard-to-abate sectors. In iron and steel, hydrogen-based direct reduced iron (DRI) com-bined with electric arc furnaces can replace coal-based primary steelmaking. In cement and lime, hydrogen offers high-temperature heat and low-carbon clin-ker alternatives. In aviation and shipping, hydrogen-derived fuels such as green ammonia and methanol are leading candidates for long-haul and heavy trans-port, where batteries are less feasible. In chemicals and fertilizers, green hydrogen can directly substitute the “grey” hydrogen currently used in ammonia and downstream chemical production (IEA 2022; Financial Times 2023).
Green Ammonia: Green ammonia is emerging as a key pillar of the clean energy transition, produced by synthesising nitrogen and hydrogen where the hydrogen comes from renewable-powered electrolysis instead of fossil fuels. Unlike conventional ammonia, which contributes significantly to CO₂ emissions, green ammonia offers a carbon-free alternative for fertilizer production, long-duration energy storage and as a potential fuel for shipping and power generation. Its advantages include high energy density, easier storage and transport compared to hydrogen and compatibility with existing global ammonia infrastructure. Countries leading investments in green ammonia include Australia, Japan, Saudi Arabia, India, Germany and the Netherlands, with major projects underway in the Middle East and Northern Europe aimed at both domestic use and export markets. Together, these initiatives position green ammonia as a strategic enabler of global decarbonisation in both energy and agriculture.
Storage and system services: Beyond industrial uses, hydrogen can serve as long-duration seasonal storage and as a versatile feedstock for synthetic fuels (power-to-X). Electrolyser co-location with large renewable plants minimises curtailment and creates predictable production profiles. However, technical barriers remain: round-trip efficiencies are relatively low (30–45% for power → H₂ → power), electrolyser capex and durability are still under pressure and storage/transport infrastructure is costly. Achieving cost competitiveness depends on scaling electrolysers and reducing renewable electricity costs (IEA 2022; AP News 2023).
Scale and policy momentum: Despite strong policy momentum, with more than 40 countries adopting national hydrogen strategies, green hydrogen accounts for less than 1% of global production today. Scaling up deployment, particularly in heavy industry and shipping, is critical to reduce costs and reach parity with fossil-based hydrogen under carbon pricing or low-cost renewable scenarios (IEA 2022; Financial Times 2023).
Regional and Global Momentum
Renewables expansion is accelerating across key regions. China continues to dominate global solar deployment, adding about 87 GW in 2022, an unprecedented 216 GW in 2023 and a further 277 GW in 2024, taking its cumulative installed solar capacity to nearly 887 GW by the end of 2024. In comparison, India added around 13.4 GW in 2022, but saw a slowdown to ~7.5 GW in 2023 due to policy and supply-chain challenges. However, India rebounded strongly in 2024 with 24.5 GW of new solar capacity, its highest-ever annual addition, bringing cumulative installations to around 96 GW by early 2025. China remains far ahead: i ~ 76 GW of new wind power, bringing its total wind capacity to around 441 GW. India, by contrast, added 3.4 GW of wind capacity in 2024, raising its total wind capacity to about 48.16 GW.
The European Union has rapidly scaled up solar and wind power: in 2024 alone, the EU installed around 60 GW of solar PV, maintaining similar additions as in 2023, which helped accelerate the decline in fossil generation; wind and solar together avoided €59 billion in fossil fuel import costs (gas + coal) for the EU power sector due to gains under the European Green Deal and REPowerEU.
In the United States, the Inflation Reduction Act (IRA) has catalysed a record-year for solar installations: in 2024, about 50 GW of new solar capacity was added, accounting for 84% of all new electricity generation capacity added that year, driven by the incentives under the IRA.
Decentralisation, Community Participation and Resilience
Distributed energy resources such as rooftop PV, community wind, and small-scale biogas provide critical resilience benefits by reducing transmission losses, improving local reliability and enabling modular, staged investments. Microgrids with integrated storage offer black-start capability and islanding for critical infrastructure during outages, which is particularly valuable for disaster-prone regions. Beyond technical advantages, community and prosumer energy models generate local economic benefits, from lower household bills to land lease revenues, while also enhancing social acceptance of renewable projects. Evidence from Europe and developing countries shows that community energy models strengthen social buy-in and provide sustained local employment and fiscal benefits (ILO 2022; REN21 2023).
The Path Ahead: From Awareness to Action
The period from 2020 to 2024 revealed both the fragility and the resilience of global energy and climate systems. On one hand, the rapid rebound of emissions following the COVID-19 slowdown and the continued expansion of fossil fuel infrastructure underscored how deeply entrenched carbon-intensive pathways remain (IEA 2023a; Global Carbon Project 2023). On the other hand, these same years witnessed record-breaking growth in renewable energy deployment, proving that the technological and economic foundations of a cleaner future are already being laid (IRENA 2023; REN21 2023). This duality highlights both the urgency of accelerating change and the possibility of success when innovation, policy and public will align.
To remain within the 1.5°C limit set by the Paris Agreement, the world must achieve annual fossil CO₂ emission reductions of roughly 4–5% throughout this decade (IPCC 2021, AR6). This means halting the development of new coal and gas assets, redirecting finance toward clean energy and ensuring that the transition is just and equitable for workers and communities most exposed to disruption (ILO/IRENA 2023; UNFCCC 2022). Beyond the technical challenge, international cooperation is indispensable—climate change is a global crisis that no nation can solve alone (IPCC 2022).
The energy transition is therefore not just about substituting one fuel with another. It represents a systemic transformation of how societies consume, produce and value energy; how capital is allocated; and how institutions support resilience and inclusion (IEA 2023b; REN21 2023). The years 2025 to 2030 represent a decisive window: actions taken now will either place the world on a trajectory consistent with net-zero pathways or lock humanity into patterns of irreversible climate damage.
Conclusion
The evidence from 2020 to 2024 makes clear that the world stands at a historic crossroads. The technological potential of renewables is no longer in doubt, political commitments are multiplying and public awareness of the climate emergency is at its peak. Yet emissions remain stubbornly high and collective action lags far behind ambition. Renewable energy is no longer peripheral; it is the cornerstone of climate resilience, economic modernisation and energy justice. The next five years will determine whether humanity seizes this opportunity or locks itself into unsustainable pathways. The choice is stark and the imperative is urgent: decisive action must happen now.
References
(Many data were sourced from different websites and newspapers and published scientific literature including the following.)
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- IEA, World Energy Investment 2023 — capital flows, investment needs and financing challenges for the
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- IRENA, Renewable Power Generation Costs (2024) — comprehensive data on LCOE and cost learning for wind, solar and other renewables.
- Jacobson, et (2024) and other peer-reviewed articles on batteries vs. hydrogen for grid storage — technical comparisons of reliability and cost tradeoffs.
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- NREL, Land-Based Wind Market Report 2023 and technology briefs — evidence on taller towers, rotor design and capacity factor improvements.
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- REN21 (2023). Renewables Global Status Report REN21 Secretariat.
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