Is the global energy transition happening fast enough to meet climate targets?

Are renewables actually replacing fossil fuels?

The short answer is no—not yet. Between 1965 and 2022, the share of renewable energy in global consumption doubled from 6.31% to 12.33%, but that growth was accompanied by a 3.39-fold increase in fossil fuel use and a 3.07-fold increase in CO2 emissions [1]. In other words, renewables are being added on top of fossil fuels, not substituting for them. This pattern means the energy transition so far has been a supplement, not a replacement.

A long-term study of global electricity efficiency from 1900 to 2017 confirms this worrying trend. Despite conversion efficiency (how well fuel is turned into electricity) rising from 6% in 1900 to 43% in 2017, and the carbon intensity of electricity dropping from 5.23 kgCO2/kWh to 0.49 kgCO2/kWh, total electricity-based CO2 emissions still rose 380-fold over that period [2]. The reason: massive growth in total electricity consumption outpaced all efficiency and cleanliness gains.

What would it take to speed up the transition enough?

A detailed modeling study for China—the world's largest energy consumer—shows what a truly accelerated transition looks like. China's goal of carbon neutrality by 2060 requires scaling up solar and wind power from 1 PWh per year today to 10–15 PWh per year by 2060 [3]. Following current policies would only reach 5–9.5 PWh per year, but by optimizing the placement of 3,844 new utility-scale solar and wind plants, expanding ultra-high-voltage transmission, and adding energy storage, China could hit 15 PWh per year—and slash the average cost of cutting CO2 from $97 per ton to just $6 per ton [3]. The catch: annual investment in solar and wind would need to jump from $77 billion in 2020 to $127 billion in the 2020s and then to $426 billion per year in the 2050s [3].

Even with that massive investment, the transition faces structural hurdles. A study of 17 multinational energy utilities found that while private companies lead investment in renewables, state-owned utilities often invest in both renewables and non-renewables in different countries, effectively slowing the overall transition [5]. Meanwhile, poorly designed 'just transition' policies—meant to phase out coal, oil, and gas fairly—risk subsidizing fossil fuel industries indefinitely unless they are fundamentally overhauled [4].

Is the real barrier technology or something else?

Technology is not the main bottleneck. The technical solutions—large-scale solar and wind, energy storage, ultra-high-voltage transmission, and even carbon capture—already exist [1][3]. The real problem is the pace of deployment and the political will to make fossil fuels more expensive or less available. For example, the Russia-Ukraine conflict in 2022 triggered a global energy crisis that pushed many countries back toward coal and gas for energy security, showing how geopolitical shocks can derail climate progress [1].

Another overlooked issue is 'efficiency dilution.' Even as individual appliances and machines become more efficient, people are adopting more energy-hungry devices (like air conditioning and data centers), so overall end-use efficiency has stayed flat at about 48% since 1900 [2]. This means future electricity demand will keep rising, and unless that demand is met entirely with renewables, emissions will continue to climb. The historical record shows that past efficiency gains did little to reduce total CO2—they were overwhelmed by growth in consumption [2].

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