Svante August Arrhenius ( / ə ˈ r iː n i ə s , ə ˈ r eɪ n i ə s / ə- REE -nee-əs, -⁠ RAY – , Swedish: [ˈsvânːtɛ aˈrěːnɪɵs] ; 19 February 1859 – 2 October 1927) was a Swedish scientist. He began his career as a physicist but is often called a chemist. Arrhenius helped create the field of physical chemistry. In 1903, he won the Nobel Prize in Chemistry, becoming the first Swedish person to receive a Nobel Prize. In 1905, he became the director of the Nobel Institute and held this position until his death.

Arrhenius was the first person to use physical chemistry to calculate how rising levels of carbon dioxide in the atmosphere affect Earth's surface temperature. His research was important for the development of modern climate science. In the 1960s, Charles David Keeling measured carbon dioxide levels in the air and found they were increasing. His findings supported the idea that this increase could lead to significant global warming.

Many scientific terms, places, and institutions are named after Arrhenius to honor his work. These include the Arrhenius equation, Arrhenius acid, Arrhenius base, the lunar crater Arrhenius, the Martian crater Arrhenius, the mountain Arrheniusfjellet, and the Arrhenius Labs at Stockholm University.

Biography

Svante Arrhenius was born on February 19, 1859, in Vik (also spelled Wik or Wijk), near Uppsala, Sweden. He was the son of Svante Gustav and Carolina Thunberg Arrhenius, who were Lutheran. His father worked as a land surveyor for Uppsala University and later held a higher position. At age three, Arrhenius taught himself to read without help from his parents. He also became very skilled at math by watching his father add numbers in his account books. Later in life, he was deeply interested in math, data, and finding patterns and rules in science.

At age eight, he entered a local school, starting in the fifth grade. He excelled in physics and math and graduated as the youngest and most talented student in 1876.

At the University of Uppsala, Arrhenius was not satisfied with the physics instructor or the chemistry teacher, Per Teodor Cleve. He left Uppsala and studied at the Physical Institute of the Swedish Academy of Sciences in Stockholm under physicist Erik Edlund in 1881.

His work focused on the conductivities of electrolytes. In 1884, he submitted a 150-page dissertation on electrolytic conductivity to Uppsala University for his doctorate. The professors, including Cleve, were not impressed and gave him a low grade. However, after his defense, the grade was upgraded to third-class. Later, his work on this topic earned him the 1903 Nobel Prize in Chemistry.

In his 1884 dissertation, Arrhenius presented 56 ideas, most of which are still accepted today with little or no change. His most important idea was that solid salts break apart into charged particles when dissolved in water. These particles, called ions, were named by Michael Faraday long before. Faraday believed ions were created only during electrolysis, which requires an electric current. Arrhenius proposed that ions exist in salt solutions even without electricity. He also suggested that chemical reactions in solutions occur between these ions.

The professors at Uppsala were not impressed by his dissertation, but Arrhenius shared it with scientists in Europe, such as Rudolf Clausius, Wilhelm Ostwald, and Jacobus Henricus van 't Hoff. These scientists were more interested in his work. Ostwald even visited Uppsala to invite Arrhenius to join his research team in Riga, but Arrhenius declined. He wanted to stay in Sweden-Norway for a while because his father was very ill and would die in 1885. He also had a job at Uppsala University.

In 1884, Arrhenius also proposed definitions for acids and bases. He believed acids are substances that produce hydrogen ions in solution, and bases are substances that produce hydroxide ions in solution.

In 1885, Arrhenius received a travel grant from the Swedish Academy of Sciences. This allowed him to study with scientists in Riga (now in Latvia), Würzburg, Germany, Graz, Austria, and Amsterdam.

In 1889, Arrhenius explained that most reactions need heat energy to start by introducing the concept of activation energy, which is a type of energy that must be overcome for molecules to react. The Arrhenius equation describes how activation energy affects the speed of reactions.

In 1891, Arrhenius became a lecturer at Stockholm University College (now Stockholm University). He was promoted to professor of physics in 1895 and became rector in 1896.

Around 1900, Arrhenius helped set up the Nobel Institutes and the Nobel Prizes. He was elected to the Royal Swedish Academy of Sciences in 1901. He held positions on the Nobel Committees for Physics and Chemistry and used them to influence prize awards for friends and deny them to enemies. In 1901, he was elected to the Swedish Academy of Sciences despite strong opposition. In 1903, he became the first Swede to win the Nobel Prize in Chemistry. In 1905, he was appointed rector of the Nobel Institute for Physical Research in Stockholm, a position he held until his retirement in 1927.

In 1911, Arrhenius won the first Willard Gibbs Award. He was elected an International Member of the United States National Academy of Sciences in 1908, an Honorary Member of the Netherlands Chemical Society in 1909, a Foreign Member of the Royal Society in 1910, an International Member of the American Philosophical Society in 1911, and a Foreign Honorary Member of the American Academy of Arts and Sciences in 1912. In 1919, he became a foreign member of the Royal Netherlands Academy of Arts and Sciences.

Later in life, Arrhenius’s theories became widely accepted, and he turned to other scientific topics. In 1902, he studied physiological problems using chemical theory and found that reactions in living organisms and in test tubes follow the same rules. In 1904, he gave lectures at the University of California on applying physical chemistry to the study of toxins and antitoxins. These lectures were published in 1907 as Immunochemistry. He also studied geology, astronomy, cosmology, and astrophysics. He proposed that the Solar System formed from interstellar collisions and explained phenomena like comets, the solar corona, the aurora borealis, and zodiacal light using radiation pressure. He also suggested that life might have traveled between planets via spores

Marriages and family

He married twice. First, he married his former student Sofia Rudbeck (1894–1896), and they had one son, Olof Arrhenius [sv; fr]. Later, he married Maria Johansson (1905–1927), and they had two daughters and one son.

Arrhenius was the grandfather of Agnes Wold, a bacteriologist; Svante Wold, a chemist; and Gustaf Arrhenius [sv; fr; ru; zh], an ocean biogeochemist.

Svante Thunberg, the father of climate activist Greta Thunberg and a distant relative of Arrhenius, was named after him.

Greenhouse effect

In 1896, a scientist named Arrhenius used basic science principles to calculate how much Earth’s surface temperature might rise if more carbon dioxide (CO₂) entered the atmosphere. He studied how CO₂ traps heat, a process called the greenhouse effect. Arrhenius believed that human activities, like burning fossil fuels, could release enough CO₂ to cause global warming. His ideas became important in modern climate science. Arrhenius built on the work of earlier scientists, including Joseph Fourier, John Tyndall, and Claude Pouillet. He wanted to understand if greenhouse gases, like CO₂ and water vapor, could explain changes in Earth’s temperature during ice ages and warmer periods.

To study this, Arrhenius used infrared observations of the moon taken by scientists Frank Washington Very and Samuel Pierpont Langley at the Allegheny Observatory. He calculated how much heat is absorbed by CO₂ and water vapor in Earth’s atmosphere. He used a scientific rule called the Stefan–Boltzmann law to create a formula. His original formula described how changes in CO₂ levels might affect Earth’s temperature. In this formula, Arrhenius called CO₂ “carbonic acid,” a term now used only for the liquid form H₂CO₃. A modern version of his formula is still used today. It shows how the concentration of CO₂ (C) compared to its starting level (C₀) affects the amount of heat trapped in the atmosphere (ΔF), measured in Watts per square meter. Scientists have found that the value α (alpha) for CO₂ is 5.35 (±10%) W/m².

Arrhenius based his calculations on data from his colleague Arvid Högbom. He predicted that burning fossil fuels would release enough CO₂ to cause global warming. His work considered how changes in water vapor and temperature differences across Earth might affect warming, but he did not account for clouds or how heat moves upward in the atmosphere. Today, his work is seen as the first proof that rising CO₂ levels could cause warming, assuming other factors remain the same.

In 1900, another scientist, Knut Ångström, criticized Arrhenius’s findings. Ångström published the first modern infrared absorption spectrum of CO₂, showing that adding more CO₂ might not increase heat absorption because the atmosphere already absorbed most of the infrared radiation. Arrhenius disagreed and dismissed this criticism in 1901. He later wrote about his ideas in a book for the general public, suggesting that human-caused CO₂ emissions could prevent a new ice age and help feed a growing population.

Scientists now agree that changes in Earth’s orbit have historically influenced the timing of ice ages, while CO₂ acts as a key factor that amplifies temperature changes. However, CO₂ levels today are much higher than they have been in millions of years, when Earth was much warmer and sea levels were much higher.

Arrhenius estimated that reducing CO₂ levels by 0.62–0.55 would lower temperatures by 4–5°C, while doubling CO₂ levels could raise Arctic temperatures by 8–9°C. In his book Worlds in the Making, he described the idea that Earth might become a “hot house” if CO₂ levels rose.

In 1971, scientists S. Ichtiaque Rasool and Stephen Henry Schneider calculated that doubling CO₂ levels would raise Earth’s temperature by about 0.8°C, and increasing CO₂ tenfold would raise temperatures by 2.5°C. They concluded that burning more coal could not prevent an ice age. Both Arrhenius and Ångström were correct in their general ideas but incorrect in their specific predictions about temperature changes.

Works

• 1884, Research on the Conductivity of Electrolytes, doctoral dissertation, Stockholm, Royal publishing house, P. A. Norstedt & Söner, 155 pages.
• 1896a, On the Influence of Atmospheric Carbon Dioxide Content on Ground Surface Temperature, in the Proceedings of the Royal Swedish Academy of Science, Stockholm 1896, Volume 22, No. 1, pages 1–101.
• 1896b, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science (fifth series), April 1896, Volume 41, pages 237–275.
• 1901a, On the Heat Absorption by Carbon Dioxide, Annalen der Physik, Vol. 4, 1901, pages 690–705.
• 1901b, On the Heat Absorption by Carbon Dioxide and Its Influence on the Temperature of the Earth's Surface. Abstract from the proceedings of the Royal Academy of Science, 58, 25–58.
• Arrhenius, Svante. The Spread of Life in the Universe. Die Umschau, Frankfurt a. M., 7, 1903, 481–486.
• Lehrbuch der kosmischen Physik (in German). Vol. 1. Leipzig: Hirzel. 1903. Lehrbuch der kosmischen Physik (in German). Vol. 2. Leipzig: Hirzel. 1903.
• 1906, The Likely Cause of Climate Fluctuations, Meddelanden från K. Vetenskapsakademiens Nobelinstitut, Vol. 1, No. 2, pages 1–10.
• 1908, Worlds in the Making (Das Werden der Welten); the Evolution of the Universe, Academic Publishing House, Leipzig, 208 pages.