The goal of this blog is to create a list of super facts. Important facts that are true with very high certainty and yet surprising, misunderstood, or disputed by many. This blog aims to be challenging, educational, and fun, without it being clickbait. I determine veracity using evidence, data from reputable sources and longstanding scientific consensus. Prepare to be challenged (I am). Intentionally seek the truth not confirmation of your belief.
Superfact 104: The evolution of eyes is convergent, meaning different, unrelated animal species independently evolved similar types of eyes. Biologists estimate that eyes have evolved independently between 40 to over 65 different times across various lineages. An example is the evolution of Cephalopod eyes (like squid and octopus) and vertebra eyes.
First of all, eyes evolved. Creationists often say that eyes are too complex too have evolved. That is because the eye is composed of many interdependent, finely tuned parts, for example, the cornea, iris, retina and lens. And that it cannot function without all those components already evolved. This is referred to as the argument for irreducible complexity.
The problem with that argument is that evolution is not linear. The various intermediate steps may not have functioned as the final product but could still have provided evolutionary advantage. There are many intermediate “eyes” existing today in nature. As you can see in the picture below the evolution of the vertebra eye did not start with all the current parts.
Major stages in the evolution of the eye in vertebrates. Matticus78 at the English-language Wikipedia, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons.
In addition, the evolution of eyes is largely convergent. Biologists estimate that eyes have evolved independently between 40 to over 65 different times across various lineages. The cephalopods (like octopuses and squid) and vertebrates (like humans, mammals, birds and fish) evolved their camera-style eyes completely independently. This is one of nature’s most famous examples of convergent evolution, where two unrelated species arrive at the exact same biological solution to survive in their environments.
The fact that eyes evolved and that the irreducible complexity argument does not work comes as a surprise to creationists. That the various kinds of eyes in nature evolved separately but converged on similar complex structures is in general an amazing fact. It is a kind of an important fact that is true. Therefore, it is a super-fact in my opinion.
Eyes Are not an Example of Irreducible Complexity
The evidence that the complexity of eyes is not an example of irreducible complexity is strong. We can trace lineages via DNA and sub-optimality. We can also simulate the evolution of the eye using computers. In a simulation based on mutations and natural selection it took 363,992 generations to evolve an eye from an eyespot (light-sensing organelle) to a complex camera type eye, which probably corresponds to around half a million years. See The Evidence for Evolution by Alan R. Rogers.
I can add a personal anecdote. In my job as a software engineer trying to find better algorithms for sorting mail using the photos of the mail, including the address block, I tried using genetic algorithms. Genetic algorithms is a type of Artificial Intelligence that simulates evolution to create better systems (better algorithms and software). The genes corresponding to the best algorithms were allowed to propagate, recombine and mutate. That was the natural selection component.
What I saw was that the genetic algorithm could evolve the system into a complex and effective system of interdependent complex components that did not exist at the beginning. Several complex components working together did not require that components/parts evolve one after another. They can go through several formats from primitive to advanced and they can have different functions along the way. Some parts might evolve and then disappear and new kinds of parts pop up, as the total algorithm kept evolving. There is no reason to believe that irreducible complexity even exists.
While both eyes share features like a cornea, iris, lens, and retina, they were built from different starting materials and possess some structural differences. In vertebrate eyes, the nerve fibers route before the retina, blocking some light and creating a blind spot where the fibers pass through the retina. In cephalopod eyes, the nerve fibers route behind the retina, and do not block light or disrupt the retina. In other words, the cephalopod eyes not having a blind spot are more perfect than our eyes.
Look into the loving eyes of the squid. He does not have a blind spot. Atlantic Ocean squid macro photo. Shutterstock asset id: 1859007028 by Rui Palma
Super fact 103: The moon is always turning the same side towards us. This side is often referred to as the near side of the moon. The back side, which we can’t see from Earth, is often referred to as the far side of the moon. However, there is no side of the moon that is always dark. The near side of the moon and the far side of the moon both have day and night (in a 29.5 day cycle). Another interesting fact is that even though the near side and the far side of the moon get the same amount of light they are very different.
The near side of the Moon on the left and the far side of the Moon on the right. They are both full about once a month but at different times. They look quite different and are quite different. Elements of this image were furnished by NASA. Stock Photo ID: 2157518223 by Claudio Caridi.
Below is a youTube video showing an animation composed of actual satellite photos by NASA. It shows the far side of the moon, illuminated by the sun, as it crosses between the DSCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) and telescope, and the Earth – one million miles away.
The video has frequently been shown on social media, and I’ve seen many comments stating that it is fake because the back side / far side of the moon is not dark in the video. However, the sun is behind us in the video and shining on both Earth and the far side of the moon. The far side is not always dark.
This is a super fact because many people mistakenly think there is a permanently dark side of the moon, which we know is incorrect and understanding the basics about the moon, the most prominent celestial object in the sky, aside from the sun, is kind of important.
Moon Photos
This is a close up photo of the near side of the moon. It is a full moon. Free picture from Pexels by Jay Brand.This is also a close up photo of the near side of the moon, but it is a crescent moon, which means that the far side, or the back side, is the side that is mostly lit up. In other words, the far side of the moon has day. Free picture from Pexels by Sevde.
I took the photo below with my phone a few minutes ago this evening. The little dot on the left (it is not twinkling) is the planet Venus. The moon is currently a crescent, which means that at the moment of my writing this the back side / far side of the moon has day. The sun is shining down on the far side, and it is reflecting light back into space. The back side / far side is almost a full moon right now, but we can’t see that from Earth.
The dot on the left is Venus. On the right is the crescent moon. This photo is taken with my phone a few minutes ago (as of this posting).This is a zoomed out photo taken at the same time as the photo above. I zoomed out to capture a second dot up in the left corner. That’s another planet, the planet Jupiter (also not twinkling).
Interesting Moon Facts
I thought I might as well mention a few interesting facts about the moon.
The Moon’s nearside and farside Image: NASA LRO / Jatan Mehta
The far side of the moon is different. As you can see in the YouTube video and photo above, the far side looks different from the nearside and it is different in appearance and terrain. The near side of the moon has large, dark, flat-lying basins called maria. They look like oceans. The far side is a lot more rugged and covered by lots of craters. Another difference is that the far side of the moon has a much thicker crust compared to the near side.
The moon is drifting away from earth at about 3.8 centimeters per year. The moon is moving away from earth due to the gravitational forces between the moon and earth, which also causes tidal bulges in the Earth’s oceans and the moon. Back in high school I took a difficult physics test for a competition and one of the questions was to show that the moon was moving away from earth due to gravitational forces and calculate by how much. I did not solve that one.
The moon was likely created by a celestial collision. The most widely accepted explanation for the existence of the moon is that the Moon was created when a planet-like object, the size of Mars slammed into Earth, soon after the solar system began forming. That was about 4.5 billion years ago.
NASA found water on the moon. In 2020, NASA announced the discovery of water on the surface of the Moon. The NASA video below features more interesting facts about the moon.
If you visit this link you’ll find an interactive 3D animation using the NASA Visualization Technology Applications and Development (VTAD) technology. By using your mouse, you can view the moon from many different angles and positions (both the near side and the far side of course).
Super fact 102: Stars twinkle but planets do not. Planets reflect sunlight, like the moon, whereas stars emit intense light like the sun. However, stars are thousands of times further away.
The light from stars is intense allowing stars to have much smaller discs in the sky for the same amount of light as a planet. Shutter Stock Illustration ID: 566774353 by Nostalgia for Infinity.
The Sun and the Moon appear to have roughly the same sized disk in the sky, about 0.5 degrees of arc, because the Sun is roughly 400 times wider than the Moon but also about 400 times farther away. However, the moon, which reflects sunlight but does that emit any, is much fainter than the sun in our sky. The Sun provides approximately 400,000 times more light to Earth than the full Moon. If you were to move the sun farther away until it provided the same amount of light as the moon you would have to move the sun 632 times farther away until it became a tiny point in comparison to the moon.
The planets in our solar system, Venus, Jupiter, Mars, Mercury, Saturn, etc., appear in the sky as small discs reflecting light whereas the stars appear as intense points of light with a disc diameter that is thousands of times smaller than that of the planets. However, we can’t see the difference with the naked eye. Both planets and stars appear like points of lights to us, but the difference in disc size in the sky is very big.
Planets reflect light whereas the stars appear as intense points. Shutterstock asset id: 2709145593 by buradaki
Because stars are tiny intense points of light Earth’s atmosphere can easily refract (bend) their light. This is known as scintillation. I can add that the light from stars that are low in sky go through more atmosphere and therefore twinkle more. Since planets appear as tiny discs rather than tiny points, planets create a steadier beam of light, which averages out atmospheric turbulence. In addition, dust particles in space and in the atmosphere can more easily block the light from stars compared to that of planets, because the planets have much larger discs in the sky (thousands of times larger).
To the naked eye a planet and a star point look light points of light. In a telescope the planet will turn into a disc, but the star will remain a bright point of light. For example, a piece of space dust can easily make the star twinkle by moving in front of it but won’t do that to the planet. Note: planets are much smaller than stars, but they are much closer and can look bigger.
Since this fact is not scientifically under question, a lot of people don’t know it, and it is kind of important to anyone interested in the night sky, I consider it a super fact. I should say that I borrowed this super fact from Jacqui Murray’s blog worddreams.
Planets Reflect Light like the Moon
Planets reflect light. They don’t shine and emit light like the sun or the stars.
Jupiter in true color, taken by the Hubble Space Telescope in January 2024Saturn and its prominent rings, as captured by the Cassini orbiter. This natural color view of the planet Saturn was created from images collected shortly after Cassini began its extended Equinox Mission in July 2008.Pluto from NASA/JHUAPL/SwRI. NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute, Public domain, via Wikimedia Commons. NASA’s New Horizons spacecraft captured this high-resolution enhanced color view of Pluto in 2015.
If you place a light bulb (white light includes a spectrum of colors) in front of a container filled with hydrogen and then you let the light pass through a prism, it will split into the different colors (red, yellow, blue, etc.) forming a rainbow, as prisms do. You see this every time you see a rainbow in nature. However, if you measure carefully, as in the experimental setup below, you will notice that some frequencies are missing. That’s because the hydrogen gas will absorb certain frequencies.
This is true, not just for hydrogen, but for all elements/atoms and molecules. Atoms and molecules have light absorption patterns that are unique to the atom/element in question. The dark lines in the spectra are referred to as Frauenhofer lines. In a sense, all elements have a thumb print resulting from their so called absorption spectra. This makes it possible to identify the elements in a star and their proportions.
Absorption spectrum / Frauenhofer lines of the hydrogen atom. Shutterstock asset id: 1305568666 by Emir Kaan
Before the discovery of absorption spectra, it was sometimes believed that humanity would never know the chemical elements of stars. Even today many people are surprised to hear that we can indeed know what stars are composed of just by looking at their light. In addition to identifying elements in the upper layers / atmosphere of stars you can use the same absorption spectra to determine the relative velocity of stars compared to us and sometimes the distance to the stars. This is an old discovery that is surprising and important to our understanding of the world and therefore a super fact in my opinion.
Examples of Absorption Spectra
An interesting, related fact is that Helium was discovered in the Sun before it was found on Earth, with the help of emission spectra (August 18, 1868). Emission spectra are the opposite of absorption spectra. It should be noted that while emission spectra are commonly used for identifying the composition of interstellar gas, absorption spectra are commonly used for identifying the composition of stars.
Absorption and Emission Spectrum of Helium Shutterstock asset id: 1724296909 by MoFaroukAbsorption and Emission Spectrum of Carbon Shutterstock asset id: 1725934867 by MoFaroukSolar spectrum with Fraunhofer lines as it appears visually. The solar spectrum is a combination of spectra from multiple elements: nl:Gebruiker:MaureenVSpectrum-sRGB.svg: Phrood~commonswikiFraunhofer_lines_DE.svg: *Fraunhofer_lines.jpg: Saperaud 19:26, 5. Jul. 2005derivative work: Cepheiden (talk)derivative work: Cepheiden, Public domain, via Wikimedia Commons.
Using Redshift to Determine how fast Stars are Moving Compared to us
A star or galaxy that is moving towards us will have a blue shifted spectrum. A star or galaxy that is moving away from us will have a red shifted spectrum. Red shifted means that the absorption lines have moved towards red because the frequency of the light has been shifted due to the motion.
This is called the doppler effect. You can notice this phenomenon for the case of sound when an ambulance is coming towards you and then speeding by you. The sound changes. The astronomer Hubble was using redshift to the determine that the further away a galaxy was from us the faster it was moving away from us. Measuring the redshift of a faraway galaxy or star, not only tells us its speed compared to us but can indirectly help us determine the distance to the galaxy or star.
Visualization of redshifted absorption lines are redshifted due to velocity away from observer. Top lines are for an object at rest and in the bottom picture the object is moving away. Maxmath12, CC0, via Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
There are other things you can tell from the light from stars and from their electromagnetic spectrum such as the type of star, the size of the star, and the age of the star, but that is for another post. This post is long enough.
Superfact 100: The share of fossil fuels for electricity generation is decreasing and EVs are replacing internal combustion engines. The share of hydro and nuclear energy, which is clean energy, is decreasing, but the sharp increase in the share provided by renewables such as wind and solar is more than making up for it. In addition, there are new clean energy sources that are very promising but not yet widely implemented such as geothermal energy and fusion energy. The energy landscape is changing rapidly.
Share of electricity generation from fossil fuels, renewables and nuclear, world. Measured as a percentage of total electricity produced in the world. Fossil fuels include coal, oil and gas. Renewables include solar, wind, hydropower, bioenergy, wave and tidal. Data source Ember (2026): Energy institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY.
As can be seen in the graph above the share of electricity in the world generated by fossil fuels has gone down in recent years (from 66.48% in 2015 to 57.39% in 2025), and the share of electricity generated by nuclear has also gone down (from 10.55% in 2015 to 8.85% in 2025) whilst the share of electricity generated by renewables has increased (from 22.97% in 2015 to 33.76% in 2025). This is even though the most prominent source of renewable energy, hydro, has decreased its share substantially (from 16.2% in 2015 to 14% in 2025) as can be seen in the graph below.
What is going on is that two sources of renewable energy, wind and solar, have increased their share of electricity generated substantially (wind: from 3.5% in 2015 to 8.5% in 2025) and (solar: from 1.1% in 2015 to 8.7% in 2025), which can be seen in the graph below. It should be noted that renewable energy encompasses solar, wind, hydropower, bioenergy, geothermal, wave, and tidal sources.
To play around with the graph above and other similar graphs click here and select and look at the bottom charts. To play around with the graph below and similar graphs click here and select and look at the bottom charts.
Share of electricity production by source, World. Data source (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY.
So far, I’ve been talking about the share of electricity production in the world by different energy sources. However, the world is using more and more electricity. Populations are growing, economies are growing, and the world is electrifying, for example, because of the worldwide adaption of EVs.
Just because an energy source’s share of electricity production is decreasing does not mean its total global electricity generation by that source is decreasing. In fact, as the share of electricity production by fossil fuels has decreased, the total production of electricity by fossil fuels has increased, well up until now. For the first time in history the total global electricity generation by fossil fuels went down in 2025. Note that since coal and oil decreased in the graph below fossil fuel consumption for electricity declined in 2025, despite s small increase in gas. This means that the use of fossil fuels is finally decreasing.
Low carbon sources met all of 2025’s electricity demand growth. Change in global electricity generation by source, 2024 to 2025. Total generation rose by 850 terawatt-hours (TWh). Note: “Other renewables” include hydropower, bioenergy, tidal and geothermal. Data source: Ember (2026). This graph comes from this page.
The practice of burning fossil fuels to generate electricity and for transportation is becoming less dominant. I believe this fact is surprising to many people, especially Americans since the current administration has taken a strong anti-renewable and anti-climate-science stance, and many Americans are not aware of what is happening in the rest of world in this regard. Superfact #100 is a super fact because the data is reliable, it is surprising to many people, and it is important.
It should be noted that we will likely keep using fossil fuels to produce fertilizers, plastics, medicines, and chemicals for a long time. However, this corresponds to only a few percent of our current use of fossil fuels and seems to be a lot better use of fossil fuels than burning it all up for energy. In fact, we may need the remaining fossil fuels for that purpose. In this post I am using data provided by Our World in Data which in turn got data from Ember Energy, or the International Energy Agency.
The Current Administration’s Opposition to Renewables and Climate Science
I am trying to keep politics out of my blog. However, the current administration’s strong opposition to and the misinformation they disseminate about renewables and climate science makes it difficult to discuss this renewable energy without bringing it up. It is an important piece in our understanding of what is going on. The misinformation about climate science (and other scientific topics) has bamboozled a lot of people and the actions taken to hinder the deployment of renewables have had real consequences. However, it is important to remember that the current situation here in the US is temporary and has a limited impact on the rest of the world.
Some actions that current administration has taken are:
Science organizations such as NOAA and NFS-NCAR have had their budgets severely cut and have been threatened to be dismantled. Websites related to climate science have been taken down. Click here to read more. NASA is also threatened to have its science programs severely cut (by 47%), as well as other programs, but it has not yet been implemented. Click here to read more.
Restricting or ordering the freezing of permits for renewables, canceling tax credits and investment credits for renewables, ordering the cancelation of renewables under construction, for additional information click here, or here.
In 2009 the EPA found that atmospheric concentrations of greenhouse gases endanger both current and future generations, enabling EPA to regulate greenhouse gases. This, so called endangerment finding was overturned in February 2026 by the administration. This article explain why there is no Scientific justification to revoke the endangerment finding.
The administration paid one billion dollars to France’s TotalEnergies in exchange for not developing windfarms on the east coast (kind of a bribe).
Pentagon has frozen permitting since last August halting more than 250 onshore wind projects, including those on private land, which is not only preventing us from meeting our energy needs, but is indirectly a violation of private property rights.
The United States is the only country to have withdrawn from the Paris Agreement (January 27, 2026). Three other countries, Iran, Libya, and Yemen, did not join.
95,000 employees, including 10,000+ with PhD’s, at government science agencies (more than a third of them) have either been laid off / fired, or left, as a result of current policies. This effects CDC, NIH (National Institute of Health), and especially anything related to climate science. Many scientists have left the US for Europe.
There is not wonder many in the United States incorrectly believe clean energy is on its way out. I should say that even though support for solar and wind has declined in the US, solar and wind remain the sources of energy that most people want the federal government to encourage over any other source of energy, according to this Pew Research article.
Important Climate and Energy Facts
As I said, the misinformation about climate science has bamboozled a lot of people. As an example. We know that climate change / global warming is happening. We have also known for several decades that the current climate change / global warming is not natural. It is caused by us, chiefly due to the burning of fossil fuels. The scientific evidence is conclusive. It includes satellites directly measuring our greenhouse gases trapping heat, the upper troposphere is cooling whilst the lower atmosphere is warming, showing that the heating is from greenhouse gases, the unnatural speed of the warming, isotope studies, climate models, etc. How many people know about this? I believe very few people do. Below are eleven related super facts.
Greenhouse gas emissions and death rates from various sources of energy. Fossil fuels and biomass are based on state-of-the art plants with pollution control in Europe and are based on older models of the impacts of air pollution on health. This means that these death rates are likely to be very conservative. The graph shows that renewables and nuclear are the cleanest and safest forms of energy. For further discussion see the article: OurWorldinData.org/safest-sources-of-energy. Electricity shares are given for 2021. Data sources: Markandya & Wilkinson (2007); UNSCEAR (2008: 2018); Sovacol et al. (2016); IPCC AR5 (2014); UNECE (2022); Ember Energy (2001). OurWorldinData.org – Research and data to make progress against the world’s largest problems. Licensed under CC-BY by the authors Hannah Ritchie and Max Roser. Citation : Hannah Ritchie (2020) – “What are the safest and cleanest sources of energy?” Published online at OurWorldinData.org. Retrieved from: ‘https://archive.ourworldindata.org/20260202-100556/safest-sources-of-energy.html’ [Online Resource] (archived on February 2, 2026).
The Share of EVs
Another phenomenon that results in less burning of fossil fuels than we otherwise would have is that electric cars and plug-in hybrid are becoming more common in the world. Going from nearly non-existent in 2010 electric cars (EVs) are now starting to show up around the world. The share of electric cars on the roads in 2024 was in the United States was 2.7%, in the world 4.5%, in China 11%, in Sweden 13% and in Norway 32%.
What matters more (for the future) is the sale of new EVs and plug-in hybrids. The share of new cars that are electric was 22% for the world, 10% in the United States, 21% in the EU, 28% in the United Kingdom, 48% in China, 58% in Sweden, 92% in Norway. In 2025 the share of new cars that were electric was 98% in Norway according to this website. To see more EV statistics and play around with various graphs visit this link.
One thing that might be surprising to Americans is that EVs are quite common in many other countries including EU, the Scandinavian countries, and China. Another is that EVs are indeed significantly cleaner than internal combustion engines, even when charged from a relatively dirty grid. See this super fact (29) EV Cars Indeed Emit Less Carbon Pollution.
Share of cars currently in use that are electric, 2010 to 2024. Electric cars include fully battery-electric and plug-in hybrids. With battery-electric cars is meant cars or other vehicles that are powered entirely by an electric motor and battery, instead of an internal combustion engine. With plug-in hybrid is meant cars or other vehicles that have a rechargeable battery and electric motor, and an internal combustion engine. The battery in plug-in hybrids is smaller and has a shorter range than battery-electric cars, so over longer distances, the car starts running on gasoline once the battery has run out. Data source: International Energy Agency Global EV Outlook 2025. OurWorldinData.org/energy | CC BYBattery-electric cars are depicted with brown and plug-in hybrid in blue. Share of new cars sold that are battery-electric and plug-in hybrid, 2010 to 2024. Plug-in hybrids cars can run using an electric motor and rechargeable battery, or an internal combustion engine. Their battery is usually smaller than a fully battery-electric. Data source: International Energy Agency Global EV Outlook 2025. OurWorldinData.org/energy | CC BYShare of new cars sold that are electric, 2024. Electric cars include fully battery-electric and plug-in hybrids. Data source: International Energy Agency Global EV Outlook 2025. OurWorldinData.org | CC BY
Share of electricity production by source EU, US, China
The first graph in this post depicted the share of electricity production by source for the world. The graph below breaks it up to show the share of electricity production by source for the three largest economies in the world, the United States, China and the EU. Again, the share of energy from coal, nuclear and hydro is decreasing whilst the share from wind and solar is going up for all three markets. One notable difference from the top graph is that gas keep increasing for the United States.
Share of electricity production by source, United States, European Union, and China. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldData.org/energy | CC BY
The Share of Electricity Production from Wind
Below are a few charts depicting the share of electricity production from wind. The first graph is already included in the second chart from the top (above). However, this is a close up. The second graph depicts the share of electricity production from wind for multiple countries. It should be noted that Denmark and the United Kingdom are prominent users of wind power. For Denmark the share of electricity production from wind is almost 60%. By clicking here you can play around with the graphs and generate as many different graphs as you wish.
Share of electricity production from wind. Measured as a percentage of total electricity produced in the world. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BYShare of electricity production from wind. Measured as a percentage of total electricity produced in the country or region. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BYShare of electricity production from wind. Measured as a percentage of total electricity produced in the United States, China and the European Union. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY
The Share of Electricity from Solar
The share of electricity from Solar for the world has grown from essentially 0% in the year 2000 to 3.19% in 2020 to 8.75% in 2025. For solar, the United States follows the rest of the world closely. Some countries have a higher percentage, such as the Cook Islands – 50%, Luxembourg – 30.52%, Chile – 25.06%. If you wish you can take a look here, or here, and you can play around with the different graphs. You can create millions of scenarios at your pleasure.
Share of electricity from Solar. Measured as a percentage of total electricity produced in the country or region. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY
The Share of Electricity Production from Hydropower
Hydro is a renewable energy source but its share of electricity production in the world has gone down. Unlike solar and wind, hydro is not an intermittent source of energy, so that is not necessarily something to celebrate. The intermittency of solar and wind can be mitigated using batteries, or energy sources that are not intermittent, preferably clean energy sources such as hydro and nuclear. Hydro is still the world’s most popular renewable energy source but that is changing quickly.
The graph below shows that the share of electricity production from hydropower for the world is 13.96%, USA 5.35%, Bhutan 100%, Norway 90.03%, Brazil 51.78%, Sweden 39.97%. If you wish you can take a look here, or here, and you can play around with the different graphs. You can create millions of scenarios at your pleasure.
Share of electricity production from hydropower. Measured as a percentage of total electricity produced in the world. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BYShare of electricity production from hydropower. Measured as a percentage of total electricity produced in the world and five countries (Bhutan, Norway, Brazil, Sweden, United States). Bhutan remains at 100% hydro, Norway went from 99.12% in 1985 to 90.03% in 2025, Brazil went from 92.10% hydro in 1985 to 51.78% in 2025, Sweden went from 51.76% hydro in 1985 to 39.97% in 2025, the United States went from 10.81% hydro in 1985 to 5.35% in 2025. The world went from 20.02% hydro in 1985 to 13.96% in 2025. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY
The Share of Electricity Production from Nuclear
The share of electricity production in the world from nuclear went down from 15.06% in 1985 to 8.85% in 2025, which is a significant drop. During the same time the share of electricity production from nuclear in the United States went from 15.20% in 1985 to 17.36% in 2025, for China the numbers are 0% in 1985 to 4.61% in 2025, and for EU the share of electricity production in 1985 was 27.42% and in 2025 23.32%. However, in 1993% the share of electricity production in 1993 was 33.90%.
So, nuclear has taken a big step back in EU. Germany cancelled nuclear power entirely, for better and for worse. To interact with the graphs shown below or see other (millions) related charts or maps click here, or here.
Share of electricity production from nuclear. Measured as a percentage of total electricity produced in the world’s three largest economies, the United States, EU, and China. Data source: Ember (2026): Energy Institute – Statistical Review of World Energy (2025) OurWorldinData.org/energy | CC BY
Geothermal a Promising source of Energy
Another reason to believe that the energy transition away from fossil fuels has begun, is that in addition to fossil fuels losing share of total electricity produced, there are promising emerging renewables, such as Geothermal energy. Geothermal energy uses natural heat from deep within the Earth to generate electricity or heat buildings. Wells tap into underground hot water/steam reservoirs, forcing it up to spin turbines that power generators, after which the water is cooled and reinjected to replenish the source (see the picture below).
Geothermal energy production example diagram illustration. Industrial renewable green energy plant example. Steam flow from the underground hot water to turbine generator and cooling towers. Shutterstock Asset id: 1637621995 by VectorMine.
Just like renewables geothermal energy is low emissions energy source but unlike renewables it is not an intermittent energy source. It is as of yet not widely used and not cost effective. However, it appears that might change soon. The advanced drilling techniques needed are utilizing oil and gas expertise and could therefore provide a good transition from fossil fuels to geothermal.
Geothermal power plant from above Shutterstock Asset id: 2539157855 by Alrasyiqin
Is Fusion Power the Future ?
Fusion power is a clean, and near-limitless energy source generated by smashing light atomic nuclei together, usually hydrogen isotope, to form heavier ones. It is a form of nuclear power that releases immense heat. It replicates the process that powers the Sun. Unlike wind and solar it is not intermittent and can generate carbon-free baseload electricity without long-lived radioactive waste. However, it cannot yet be used to produce energy. That does not mean it will not work in the future.
Nuclear fusion power generator concept image, 3d rendering Shutterstock asset id: 2262106105 by MeshCube.
Conclusion
The share of fossil fuels for electricity generation is decreasing despite the fact that the share from hydro and nuclear is also decreasing. The reason is the spectacular increase in the share provided by wind and solar. In addition, EV cars are rapidly replacing internal combustion cars around the world, especially in the EU and China. There are also renewable or clean energy sources that show great promise even though they are not yet widespread. This means that fossil fuels, coal, natural gas, and oil, which are all dirty and dangerous energy sources, are finally being replaced by cleaner alternatives.
Super Facts 
