Claude Monet is best known for his stunning depictions of water lilies at his garden in northern France. But throughout the mid-1800s and early 1900s, the artist also frequently painted less romantic urban surroundings, with bridges, buildings, railways, and factories often rendered faintly under a hazy patina of subdued colors.
That moody touch was actually smog, according to a study in the journal Proceedings of the National Academy of Sciences that argued Monet and his contemporary, Joseph Mallord William (J.M.W.) Turner, were also chronicling the worsening effects of air pollution on London and Paris during the Industrial Revolution.
Turner’s early works, for instance, often feature sharply visible landscapes under clear skies. But his later paintings, such as his 1842 “Burial at Sea,” which last year hung at the Museum of Fine Arts in Boston, and his 1844 masterpiece “Rain, Steam, and Speed” depict hazier scenes. Both were painted as London’s skies were being choked by industrial smog, the researchers point out.
The artists’ paintings, the findings suggest, provide an early warning about environmental degradation and the climate crisis. And, the authors posit, they show how pollution helped inspire new artistic styles.
“Instead of turning away from the pollution, [the painters] use these environmental changes as a new creative impulse,” said lead author Anna Lea Albright, a climate physicist at Sorbonne University in Paris, who works on air pollution.
The authors analyzed changes in color and style in nearly 100 paintings of London and Paris by the two artists, who both worked in Western Europe during the 18th and 19th centuries. They found that as sulfur dioxide concentrations from burning coal increased in the two cities, the scenes in their paintings increasingly became blurrier, the skies whiter, the colors more muted — changes that reflect the effects air pollution can have on a landscape.
“Industrialization altered the environmental context in which Turner and Monet painted, and our results indicate that their paintings capture [the] changes,” according to the study, published in late January.
Could this all be a coincidence? The authors don’t think so. The shifts are dramatic: In Monet’s early landscapes from the mid-1800s, for instance, visibility averages about 15 miles; but in 35 of his paintings of London’s Charing Cross Bridge, completed between 1899 and 1905, visibility averages just over a half-mile. An official inquiry described London’s visibility in winter 1901 as never more than 2 kilometers, or about 1.2 miles.
The researchers also analyzed 18 paintings from four other artists from the early Industrial Revolution in London and Paris — James Whistler, Gustave Caillebotte, Camille Pissarro, and Berthe Morisot. They found that visibility in those artworks also decreased over time as air quality degraded, suggesting the changes are not merely stylistic.
Albright dreamed up the study while seeing Monet and Turner paintings at the Tate Museum in London and the Musée d’Orsay in Paris. She knew that some art historians had already argued that the two artists’ paintings depicted smog.
“It made me curious whether we could find an empirical basis for a hypothesis already existing in the art historical literature, that these paintings capture increasing air pollution during the Industrial Revolution,” she said.
Her coauthor, Peter Huybers of Harvard University, had previously taught a class on climate signals in artwork. Scientists had previously drawn connections between paintings of sunsets and the atmospheric effects of volcanic eruptions.
The new study examined 38 of Monet’s paintings of London and Paris from 1864 to 1901 and 60 of Turner’s paintings of London from 1796 to 1850. During those periods, sulfur dioxide concentrations from burning coal increased sharply.
The United Kingdom was responsible for nearly half of all global emissions of the compound between 1800 and 1850; London accounted for one-tenth of the nation’s emissions despite taking up just 1 percent of its geography. Paris industrialized at a slower pace, but it too saw a striking increase in sulfur dioxide emissions after 1850.
The authors used a mathematical model to examine changes in the sharpness of outlines of objects in the paintings over time, then compared the findings to how much sulfur dioxide was in the air, based on annual estimates of coal sold and burned in the cities.
More than 60 percent of the time, hazier paintings lined up with increases in air pollution. The authors also found that the artists used more white hues in painting skies over time, which may indicate more polluted skies, although that could also be the result of pigments in the paintings fading over time, the authors note.
The largely coal-powered early Industrial Revolution radically transformed European cities, marking “the most fundamental transformation of human life in the history of the world recorded in written documents,” according to historian Eric Hobsbawm. Factories, mills, and railways were erected, new machinery was adopted; productivity skyrocketed, and so did child child labor, inequality, and air pollution.
As smog filled the skies, early deaths from respiratory illnesses became more common. The burning of fossil fuel also spewed carbon into the atmosphere, which research suggests spurred changes in the climate as early as the 1830s.
The new paper’s findings are bolstered by “previous research highlighting Turner’s interest in growing scientific understanding of the sky, and Monet’s letters highlighting the influence of air pollution on his creativity,” said Albright.
“Without fog London would not be beautiful,” Monet famously once said.
Historians believe Monet was not simply referencing water vapor but “smog,” the word for a mix of pollution and fog not used until the 1900s.
“The emissions of pollutants was changing dramatically over this time, whereas the amount of water that was in the atmosphere, we don’t have any real reason to suspect that that was changing substantially,” said Huybers.
Jonathan Ribner, an art history professor at Boston University who has studied the depiction of air pollution in 19th-century British and French art said while “metaphors and artistic conventions” always play a role in artistic development, his own research suggests Turner and Monet were keen observers of their surroundings.
Some artists try to draw inspiration completely from their imaginations, said Ribner. But Impressionism, the style Monet employed, is really a subset of realism, he said, and though Turner was more of a Romantic than an Impressionist, it’s clear, for instance from his paintings of coal smoke, factories, and mills, that he was interested in “the real.”
The new study can’t explain the exact role pollution had in the artistic trends of the Industrial Revolution. But its conclusions challenge our understanding of the artistic movements that emerged during the Industrial Revolution, its authors say.
“Impressionism is sometimes contrasted with realism, and our results highlight that certain Impressionistic works accurately depict how sunlight filters through clouds and smoke,” said Huybers, a climatologist who focuses on the societal implications of climate change.
Albright added, “Of course, we ultimately cannot know the heart and the mind of an artist.”
“But there is an interest in what influenced the creativity of these brilliant artists, and we make the argument that air pollution was an additional factor that played a role in generating new motifs and new ways of painting.”
Correction, March 3, 2023: Due to a reporting error, an earlier version of this story misstated when Joseph Mallord William (J.M.W.) Turner’s painting “Burial at Sea” hung at the Museum of Fine Arts in Boston. The museum featured the painting last year. The Globe regrets the error.