Renewables vs Emissions
TLDR;
Renewable energy production has increased in the last 30+ years, but rising energy demand driven by population growth, economic expansion, and new technologies has outpaced renewable growth, causing emissions to increase further. Renewable capacity is forecast to grow even faster over the next few years, reducing emissions, but current trajectories suggest reductions may be insufficient without rapid acceleration in technology, policy, and investment
World renewable energy production increased nearly fourfold between 1990 and 2023, from 2280 terawatt-hours (TWh) to 8900 TWh(1). Over this period, however, CO2 emissions from energy grew from 21.1 gigatonnes (Gt) to 37.2 Gt(2). Given the urgency of climate action, why has a significant increase in renewable energy production not led to reduced emissions?
Energy production has grown
While renewable energy production has increased, so has energy production due to new technologies, population growth, rising living standards, and industrial intensification. Developing economies, especially China and India, have rapidly expanded fossil fuel use alongside nuclear and renewables due to rapid economic growth and industrialisation. Between 1990 and 2023, electricity production increased from 12,000 to 29,500 TWh(3), and while the share of electricity from renewables increased from 19% to 30%(3), total production outgrew the additional capacity provided by renewables. Meanwhile, the share of electricity from nuclear energy fell from nearly 17% to 9% in 2023(3), causing the overall proportion of low-emission electricity sources to fluctuate. So, while we may be getting more electricity from renewables than ever, we’re also producing far more electricity than ever before. Given that fossil fuel use also increased by 75% during that period(4), it becomes clearer why emissions have continued rising. Most renewables are used in electricity production, but electricity production only accounts for about a fifth of the total energy consumption. When we look at all energy use, we see that in 2023, only 14.6% of energy came from renewables(4).
Energy storage and grid infrastructure
A key issue with renewables is that they can’t produce energy constantly, such as at night for solar or on still days for wind. This, along with limited battery storage capacity, means we usually rely on fossil fuels to provide backup when demand is high or renewable production is insufficient. Fossil fuel companies have positioned themselves to benefit by promoting natural gas as a ‘bridge fuel’, claiming that during the ‘energy transition’ to a system not based on fossil fuels, gas plants can provide a lower-emission electricity source than coal. Although burning gas produces fewer CO2 emissions than burning coal, fugitive emissions - gas inadvertently lost during the extraction, processing, transport, and storage - significantly increase the methane emissions from gas. This gas is lost to the atmosphere, contributing to global warming while producing no energy. Because of this, careless extraction and handling of gas can sometimes make it worse for the atmosphere than coal, so gas is only climate-beneficial if this ‘bridge’ period is kept as short as possible and fugitive emissions are controlled. Another issue is that most electricity grids were designed and optimised for fossil fuel plants, making it harder to connect renewable sources to the grid and increase their capacity.
Fossil fuel dominance in other sectors
While much has been done to decarbonise electricity production through renewables, fossil fuels still dominate other sectors. For example, despite the increasing popularity of electric vehicles, much of the transport sector still relies heavily on fossil fuels. Aviation, shipping, and heavy goods vehicles are more difficult to electrify. Heating is complicated to decarbonise due to its reliance on existing fossil fuel infrastructure, long replacement cycles for heating systems, limited scalability of renewable heating solutions, and the difficulty of storing renewable energy at scale, especially given seasonal fluctuations in demand. Heavy industries such as construction, steel, cement and chemicals also produce emissions through their manufacturing processes because they require a lot of energy. Efforts are being made to reduce industrial emissions through less emissions-intensive processes and electrification, however, these technologies are in their early stages.
Efficiency gains and rebound effects
Energy efficiency has significantly improved in many sectors, electricity production is cheaper and more efficient than ever, and the appliances that use it often are too, such as LEDs. However, improved efficiency and lower costs can lead to a rebound effect, increasing demand and usage because they become cheaper, potentially resulting in increased fossil fuel consumption. This phenomenon, known as the Jevons paradox, doesn’t negate the benefits of improved efficiency, as it allows more people to use and benefit from electricity, raising living standards. Still, it does highlight that efficiency alone may not reduce total energy demand.
Outlook
What then is the outlook for renewables and emissions going forward? The International Energy Agency (IEA) forecasts renewable electricity production to exceed 17,000 TWh in 2030, an increase of around 91% compared to 2023, with solar PV to see the biggest gains(5). What’s more, the share of electricity from renewables is forecast to increase to 46% from 30% in 2023(5). Beyond 2030, however, the International Energy Agency has assessed three scenarios for emissions and renewable energy
Under the Stated Policies Scenario (STEPS), which is based on the current trajectory of the energy sector, fossil fuel use is expected to supply 58% of energy demand by 2050, down from 80% in 2023, leading to a 24% decrease in emissions(6). The more optimistic Announced Pledges Scenario (APS) assumes that all national energy and climate targets already made by governments will be fully met on time, reducing emissions from energy by 68% by 2050(6). Unfortunately, it is unlikely that either of these scenarios would be enough to limit global warming to below 1.5 °C by 2100.
Under the Net Zero by 2050 Scenario (NZE), 90% of energy demand must be met by clean energy, including renewables, nuclear, hydrogen, and fossil fuels fitted with carbon capture and storage technologies, by 2050(6). The final 10% of energy demand would be expected to be met by fossil fuels, mainly gas and oil, which will be offset by carbon capture(6). Should this scenario become a reality, then global warming may be kept within 1.5 °C by 2100(6). In all three scenarios, electrification increases significantly across all sectors, providing clean heating, cooling, and transport. Some sectors, such as aviation and shipping, will be harder to decarbonise and rely on biofuels and low-emission fuels to reduce emissions.
While renewable energy generation will be important in making the net-zero scenario a reality, other emerging technologies will play a major part, including battery storage, green hydrogen, carbon capture and electrification of heating and transport. Enhanced policy measures will also be required to encourage large-scale rollouts of these technologies, including subsidies for renewables and stricter regulations on emissions.
Achieving the required emissions reductions is one of the biggest challenges of the 21st century. Major obstacles remain, but sustained global cooperation, robust policy action, and technological breakthroughs can enable us to leverage all available tools - including renewables - to meet this urgent challenge
Data
Hannah Ritchie, Max Roser and Pablo Rosado (2020) - “Renewable Energy” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/renewable-energy' [Online Resource]
IEA (2024), CO2 Emissions in 2023, IEA, Paris https://www.iea.org/reports/co2-emissions-in-2023, Licence: CC BY 4.0
Hannah Ritchie and Pablo Rosado (2020) - “Electricity Mix” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/electricity-mix' [Online Resource]
Hannah Ritchie and Pablo Rosado (2020) - “Energy Mix” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/energy-mix' [Online Resource]
IEA (2024), Renewables 2024, IEA, Paris https://www.iea.org/reports/renewables-2024, Licence: CC BY 4.0
IEA (2024), World Energy Outlook 2024, IEA, Paris https://www.iea.org/reports/world-energy-outlook-2024, Licence: CC BY 4.0 (report); CC BY NC SA 4.0 (Annex A)
