What Sunsets Painted Centuries Ago Reveal About Global Air Pollution

Dramatic sunsets are undeniably gorgeous, but they portend something ominous: millions of fine particles polluting the air. Researchers are now studying sunsets painted over the past 500 years to find clues to how our air got dirtier after the Industrial Revolution.

Particulate matter in the air—pollution, essentially—scatters sunlight to create those deep red sunsets. The redder the light, the more pollution in the air. This can happen naturally, like after a volcanic eruption, and it can happen because we've been spewing pollution into the atmosphere by burning coal and driving cars.

What Sunsets Painted Centuries Ago Reveal About Global Air Pollution

Race Horses by Edgar Degas (1885-1888) via ibiblio.org

In a new study published in the journal Atmospheric Chemistry and Physics, researchers looked at 124 sunsets painted by European artists from 1500 to 2000. They found that sunsets were redder immediately after volcanoes erupted. Over time, the sunsets became redder after the Industrial Revolution, even when there were no volcanoes. In other words, these painters were inadvertent chroniclers of air quality, helping to corroborate historical climate reconstructions.

Painters aren't the only ones who unintentionally left useful climate records. A couple years ago, researchers used flowering dates in the journals of Henry David Thoreau to calculate that temperatures in Massachusetts had risen 4.3 degrees Fahrenheit since the 1840. They may not have had sophisticated instruments hundreds of years ago, but artists and writers were keen observers of their own world. Buried in our libraries and museums are these hidden weather chronicles—if we know how to look. [The Daily Climate]

What Sunsets Painted Centuries Ago Reveal About Global Air Pollution

Landscape on the Orne by Edgar Degas (1884) via Wikipainting

What Sunsets Painted Centuries Ago Reveal About Global Air Pollution

Women Before the Setting Sun by Casper David Friedrich (1818) via Wikimedia Commons