Climate Change and Energy Transitions Towards Net Negative Emissions – Part 1

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 industrialization 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 CO iwas ~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 ppm in September 2025 vis-à-vis 410 ppm in January 2020, just before the pandemic. Concurrently, natural carbon sinks weakened, highlighting their growing fragility. Clean energy gains have blunted, but not reversed, the upward trend; the carbon economy remains resilient, demanding far more rapid, systemic shifts.

Regionally, China alone accounts for ~35% of emissions, while India has surpassed the EU as the third-largest emitter.  The US emissions decreased in 2023 but remain very high and the other top emitters include the EU, Russia, and Brazil. Meanwhile, land-use change contributed ~4.2 Gt CO₂ in 2024, and natural carbon sinks collapsed wherein forests and soils sequestering only a fraction (~1.5–2.6 Gt) of historical averages (~7.3 Gt). The ongoing dependence on fossil fuels thus jeopardizes not only climate goals but also public health and ecosystem stability. The imperative is not  whether to transition but it is how swiftly and equitably that transition will occur. Therefore, we must think of net negative scenario by which CO₂ will be a source of a variety of chemicals, fuels and materials, instead of the net zero goal.

Sectoral and Regional Contributions (2023–2024)

The global sectoral breakdown of GHG in 2023 is estimated as follows: power generation (electricity and heat) ~40%, industry ~25%, transport ~20%, buildings ~7%, and other sectors ~8%. These estimates are consistent with broader analyses, which report that global electricity and heat production contributed 29–34% of emissions, with industry, transport, and buildings accounting for significant shares of the remainder (World Resources Institute; US EPA). The IEA chart, as presented in Our World in Data, provides a sectoral CO₂ breakdown that aligns with these proportions (Figure 1).

In 2024, land-use change, including deforestation and wildfires, generated an estimated 4.2 GtCO₂, marking an increase over 2023 levels (Carbon Brief). At the same time, natural carbon sinks are showing alarming signs of collapse. In 2023, forests and soils absorbed only 1.5–2.6 GtCO₂, a steep drop from the long-term average of around 7.3 GtCO₂. This decline has been linked to severe droughts and widespread wildfires across critical regions such as the Amazon, Siberia, and Canada (Le Monde.fr). Ecosystems that traditionally offset nearly half of human emissions are now failing, placing even greater pressure on global emission-reduction efforts (The Guardian).

Need for Transition and Health Impacts

Fossil fuel extraction and use now present multi-dimensional challenges, including rising extraction costs and emissions that extend beyond CO₂. These emissions encompass NOₓ, SO₂, heavy metals, aerosols, and especially toxic pollutants like mercury, which can severely impair neurological development in children. The transition away from fossil fuels is therefore not only widely recognized as necessary but also increasingly urgent. According to IPCC modelling, sectors such as energy supply and land use may achieve net-zero earlier, while harder-to-abate sectors such as buildings, transport, and heavy industry remain significant obstacles that demand coordinated and innovative mitigation pathways.

Climate Commitments and the Implementation Gap

Over 140 countries have now announced net-zero targets, collectively covering more than 90% of global GDP and emissions (IMF). However, most of these pledges remain aspirational, with only a small share supported by binding legislation or credible policy frameworks. Climate Action Tracker classifies a significant portion of these commitments as “insufficient” or lacking credibility, highlighting the urgent need for transparent, enforceable, and rigorous implementation.

At the same time, carbon pricing and subsidy reform remain weak links in climate policy. Current carbon pricing mechanisms cover only about 23% of global emissions, and many are undermined by negligible rates or offset entirely by fossil fuel subsidies (OECD). In 2022, the IMF estimated total fossil fuel subsidies, including environmental and health externalities, at around $7 trillion, or 7.1% of global GDP. Direct support from G20 economies alone reached $1.1–1.3 trillion in the same year, with preliminary 2023 figures showing only a modest decline to about $945 billion (Bloomberg NEF report). This disconnect that is ambitious net-zero targets on paper but weak policy action in practice, continues to undercut global climate progress.

Major Global Initiatives

One of the most ambitious policy frameworks is the European Union’s Green Deal, which serves as a comprehensive roadmap for achieving climate neutrality. It spans multiple dimensions, including deep decarbonization, promotion of a circular economy, investments in sustainable mobility, and the integration of green finance. By addressing emissions reductions alongside structural economic reforms, the Green Deal aims to transform Europe’s growth model while maintaining competitiveness and resilience.

The United States’ Inflation Reduction Act (IRA) represents the largest federal commitment to climate action in the country’s history. Through extensive financial incentives, tax credits, and grants, the IRA channels investments into clean energy generation, electric vehicles, advanced battery manufacturing, and domestic supply chains. By linking industrial policy with climate goals, it is designed to accelerate the energy transition while fostering technological leadership and job creation. The current administrations tariffs and economic policy have certainly given a jolt to this act.

In the Global South, India’s Mission LiFE (Lifestyle for Environment) takes a distinct approach by focusing on behavioural change and sustainable consumption. Rather than emphasizing only technological or industrial shifts, it encourages citizens and communities to adopt low-carbon practices in everyday life such as efficient energy use, waste reduction, and sustainable transport choices. By embedding sustainability into cultural and lifestyle patterns, Mission LiFE seeks to create a mass movement for climate action.

Together, these initiatives demonstrate how different regions are mobilizing capital, expanding low-carbon infrastructure, and engaging society in the transition. However, despite their significance, the combined scale of these measures remains insufficient to align with Paris Agreement 2015 targets. Without greater coordination, ambition, and global equity in climate action, current trajectories still fall short of keeping warming well below 2°C.

Technological Trends and Gaps

Solar and Wind: Solar and wind energy are now the cheapest sources of new electricity generation across much of the world, outcompeting fossil fuel alternatives. India is a leader in the global solar alliance. In 2024, renewables accounted for 74% of new global power capacity growth, with wind and solar leading the charge. Due to rapid technological innovation and economies of scale, the costs of wind and solar power have fallen dramatically ~41% and 53% lower, respectively, than the cheapest fossil-based options (AP News). This has enabled renewable energy to become not only an environmental imperative but also an economic choice for governments and investors. India has planned to reduce fossil fuel energy by 50% and CO₂ by 45% by 2030. Indeed, many hydrocarbon and chemical  companies have announced their net zero plans before 2050.

Battery Storage: Energy storage is increasingly recognized as the backbone of renewable integration. Global battery storage capacity doubled in 2024, reaching approximately 85 GW. Yet, to remain on track with climate targets, deployment would need to scale sixfold, i.e. reaching between 1,200 and 1,500 GW by 2050 (Figure 2, The Guardian). While lithium-ion batteries dominate the current market, longer-term technologies such as pumped hydro storage and power-to-gas are under development to provide durable, large-scale solutions. These innovations are critical for ensuring grid stability in systems dominated by variable renewables. Vehicle batteries are heavy and once their capacity reduced to ~80%, they become ineffective but can be used as storage batteries. China is the leader with 9% CAGR with 45 Billion USD business.

Optimal Grid Electricity Storage Post-Electrification: Batteries, Hydrogen, or Both? A comprehensive study by Jacobson, published in iScience in 2024, examines the most cost-effective electricity storage solutions for grids fully powered by wind, water, and solar (WWS) energy across 145 countries. The research evaluates three primary storage options: battery storage (BS), green hydrogen storage (GHS), and a combination of both. The findings indicate that in regions with existing conventional hydropower (CH) storage, the optimal configuration varies as follows:

1. a) Regions with only CH: No additional storage is necessary.
2. b) Regions with CH and BS: This combination is the most cost-effective.
3. c) Regions with CH, BS, and GHS: This trio offers the lowest costs in most areas.
4. d) Regions with CH and GHS: This combination is never the most cost-effective.

The study also highlights that integrating hydrogen infrastructure for both grid and non-grid applications (such as steel and ammonia production) can lead to cost reductions due to economies of scale. In summary, while GHS alone is not the most cost-effective solution, combining BS with GHS can provide a reliable and economical energy storage strategy for fully electrified grids. This approach ensures stability and efficiency in regions transitioning to 100% renewable energy sources.

Electric Vehicle Adoption: Electric vehicles (EVs) continue to gain momentum, with sales reaching nearly 18% of total global vehicle sales in 2024. This represents a major shift in consumer and industrial behaviour, supported by government incentives and expanding charging infrastructure. However, despite this growth, EV adoption remains insufficient for a systemic transformation of the transport sector, where fossil fuels still dominate. A faster rollout, especially in heavy-duty vehicles and developing markets, will be necessary to meaningfully cut oil demand and emissions (IEA). Further, the electricity must be generated using renewable energy and not the fossil fuel based power plants.

Green Hydrogen (GH2): Green hydrogen is widely seen as a potential cornerstone for decarbonizing hard-to-abate sectors such as steel, cement, and shipping. Yet, the market remains nascent, representing only about 2.7% ($4.2 billion) of the hydrogen economy in 2022. Production costs remain 1.5 to 6 times higher than fossil-based hydrogen, creating significant barriers to adoption. Nonetheless, falling electrolyser costs and scaling projects suggest a more competitive future, with potential for rapid growth if policy and investment support remain strong (IRENA). The US DOE ‘111’ policy of producing 1 kg GH2 in 1 USD in one decade (i.e. by 2031) while providing an incentive of USD 1 per kilo is welcome by GH2 producers. The Power Ministry adopted similar policy about 2 years ago with subsidy of INR 50, 40 and 30, respectively for the first, second and third year. Although it is welcome it is inadequate for promoting GH2 production in India.

Carbon Capture and Storage (CCS): CCS technologies are often described as essential for achieving net-zero emissions, particularly for sectors where direct electrification is impractical. However, deployment remains minimal compared to the scale required for 1.5 °C pathways. While pilot projects and some commercial facilities have come online, global capacity is far below the level needed to offset emissions from heavy industry and continued fossil fuel use (IEA). Without stronger policy frameworks and investment signals, CCS risks remaining a marginal technology rather than a climate solution.

Carbon Dioxide Refineries: Catalytic valorisation of CO₂ refers to using catalysts (metal, enzyme, hybrid etc.) to convert captured CO₂ into useful chemicals, fuels, or materials (e.g. methanol, higher alcohols, LPG, DME, SAF, syngas) rather than simply storing or releasing it. Recent reviews highlight several promising routes (electrochemical, thermochemical, photochemical, plasma‐assisted), but also point out major challenges: achieving high selectivity, breaking the strong C–O bonds, managing C–C coupling for longer carbon chains, lowering energy input, and ensuring stability of catalysts under industrial conditions. One useful recent example: β-Mo₂C nanoparticle catalysts supported on silica (SiO₂) have shown good performance in reverse water‐gas shift reactions, converting CO₂ to carbon monoxide (CO) with high mass activity and structural stability at elevated temperatures. My lab is also actively working in this area.

Fossil Infrastructure Lock-In: Despite rising investment in renewables, the persistence of fossil fuel infrastructure investments paints a contradictory picture. Massive capital continues to flow into LNG terminals, pipelines, oil refineries, and even new coal plants, locking in decades of future emissions and undermining climate commitments (Figure 3, Bloomberg NEF). This highlights the stark gap between declared ambition and material action, reinforcing concerns that the global energy transition is not yet aligned with Paris Agreement goals.

Emissions Reductions Essential by 2030

The scientific consensus, as highlighted in the IPCC’s Sixth Assessment Report (AR6), is unequivocal: to limit global warming to 1.5 °C, GHG must fall by roughly 50% by 2030 compared to 2019 levels (IPCC). Current national pledges under the Paris Agreement called the Nationally Determined Contributions (NDCs) remain insufficient. If implemented in their present form, they would lead to a median warming of around 2.8 °C by 2100, with a likely range of 2.1–3.4 °C (IPCC). Such overshoot risks triggering tipping points in Earth systems, including large-scale ice sheet melt, Amazon rainforest dieback, and destabilization of permafrost carbon stores, all of which would further amplify warming.

Carbon Budget Depletion

The urgency of rapid emissions cuts is underscored by the shrinking global carbon budget. As of 2025, AR6 estimates place the remaining carbon budget for a 50% chance of staying below 1.5 °C at approximately 305 GtCO₂, while more recent analyses suggest it may be closer to just 160 GtCO₂ (ESSD). With annual emissions currently averaging ~40 GtCO₂, this budget could be exhausted within the next 6–8 years, effectively closing the window for stabilizing warming at 1.5 °C (Carbon Brief; The Climate Brink; Down To Earth). Alarmingly, one study estimates that 20% of the 1.5 °C carbon budget was already c

onsumed between 2020 and 2024 (ESSD). Indeed, the International Meteorological Organisation (IMO) predicts that the targeted 1.5 ^oC will be breached by 2027. These figures highlight the razor-thin margin left for action and the growing risk of overshooting critical climate thresholds. A carbon budget depletion trend as shown in Figure 6 showing the decline of remaining carbon budgets from 2020 through 2025—could effectively highlight how rapidly the world is burning through the budget. The data from recent studies suggesting the budget dropped from ~500 GtCO₂ (2021) to ~130 GtCO₂ (2025) could be visualized.

 

Systemic Impacts of the Energy Transition

The energy transition is not only about substituting fossil fuels with renewables but also about reconfiguring 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 globalization, technological innovation, and socio-economic development, making electricity systems a key barometer of progress. Countries that succeed in modernizing 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 resilience.

One bold idea is the creation of a universal or interconnected global grid, for example, operating at a standardized 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 standardization.

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 optimization have driven down levelized 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 benefiting 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 continuously produced through the wind blades and the remaining by solar.

Hydropower: Large-scale hydro remains the world’s most important dispatchable renewable, offering seasonal storage, grid inertia, and balancing services. However, its output is increasingly sensitive to hydrological variability, with droughts and reduced reservoir inflows lowering generation in key producing countries. Pumped hydropower continues to provide the most cost-effective long-duration storage solution, 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 decarbonize 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 emphasize prioritizing waste and residue streams over dedicated energy crops to maximize 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 decarbonizing 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

Decentralization and resilience. Distributed renewables 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 realize 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 investment 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 diversity; 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, generating stable local value while reducing exposure to volatile 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 centralized 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 Decarbonization

Green hydrogen, produced via electrolysis powered by renewable electricity, is widely seen as essential for decarbonizing hard-to-abate sectors. In iron and steel, hydrogen-based direct reduced iron (DRI) combined with electric arc furnaces can replace coal-based primary steelmaking. In cement and lime, hydrogen offers high-temperature heat and low-carbon clinker alternatives. In aviation and shipping, hydrogen-derived fuels such as green ammonia and methanol are leading candidates for long-haul and heavy transport, 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 synthesizing 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 decarbonization 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 minimizes 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 catalyzed 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.

Decentralization, 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 modernization, 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.)

• Biogas / Biomethane reviews (e.g., López et al., Applied Sciences 2024; Kabeyi, Sustainable Energy 2022)
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• IEA (2023b). World Energy Outlook 2023. International Energy Agency.
• IEA, Electricity – Renewables 2024 and World Energy Outlook 2024 — authoritative global projections and policy analysis on renewables, storage and integration.
• IEA, Global Hydrogen Review 2023 and World Energy Outlook/World Energy Investment (2023–2024).
  Ember & SolarPower Europe / European Commission analyses — data and policy assessments showing avoided gas expenditures from wind and solar in 2022 and REPowerEU targets (biomethane 35 bcm). Useful for EU-specific claims.
• IEA, World Energy Investment 2023 — capital flows, investment needs and financing challenges for the transition.
• ILO/IRENA (2023). Renewable Energy and Jobs – Annual Review 2023.
• IPCC (2021, 2022). AR6 Climate Change 2021: The Physical Science Basis and 2022 Mitigation of Climate Change. Intergovernmental Panel on Climate Change.
• IRENA (2023). Renewable Capacity Statistics 2023. International Renewable Energy Agency.

• IRENA, Renewable Power Generation Costs (2024) – comprehensive data on LCOE and cost learning for wind, solar and other renewables.

• IRENA, Renewable Power Generation Costs (2024) — comprehensive data on LCOE and cost learning for wind, solar and other renewables.
• Jacobson, et al. (2024) and other peer-reviewed articles on batteries vs. hydrogen for grid storage — technical comparisons of reliability and cost tradeoffs.
• LBNL / Lawrence Berkeley National Laboratory — technology advancement summaries for wind and PV (see LBNL reports cited in earlier search results).
• NREL, Land-Based Wind Market Report 2023 and technology briefs — evidence on taller towers, rotor design, and capacity factor improvements.
• Peer-review & technical studies: LBNL and NREL wind/PV technology briefs and Lazard/IRENA cost analyses for LCOE, life-cycle, recycling and material-supply constraints.
• REN21 (2023). Renewables Global Status Report 2023. REN21 Secretariat.

UNFCCC (2022). NDC Synthesis Report. United Nations Framework Convention on Climate Change.