Atmospheric History Captured in Sunset Colors of Old Paintings

Old World artists captured the state of the climate in their paintings of sunsets centuries ago, according to a new study.

Writing in the journal Atmospheric Chemistry and Physics, a team of Greek and German researchers report that the colors of sunsets painted by artists in centuries past can be used to estimate pollution levels in Earth's past atmosphere.

The researchers cite the 1815 eruption of Tambora volcano in Indonesia, the largest volcanic eruption in recorded history. The event sent a huge plume of volcanic ash and smoke into the air, and the particulate matter ejected by the volcano scattered sunlight in a particular way, making sunsets appear more bright red and orange in Europe for a number of years.

"Nature speaks to the hearts and souls of great artists," said lead study author Christos Zerefos, a professor of atmospheric physics at the Academy of Athens in Greece. "But we have found that, when coloring sunsets, it is the way their brains perceive greens and reds that contains important environmental information."

For their study, Zerefos and his team studied high-resolution photographs of paintings of the sunset made between the years 1500 and 2000. In this 500-year period, the world saw more than 50 large volcanic eruptions.

The researchers theorized that they could ascertain information about the amount of aerosols in the atmosphere based on the relative amounts of red and green along the horizon in the paintings.

"We found that red-to-green ratios measured in the sunsets of paintings by great masters correlate well with the amount of volcanic aerosols in the atmosphere, regardless of the painters and of the school of painting," Zerefos said in a statement.

To corroborate their theory, the researchers commissioned a well-known painter to paint sunsets during and after the passage of the Saharan dust cloud over the Greek island of Hydra in June 2010. The painter was reportedly unaware of the dust storm. The researchers found that more pollution in the atmosphere correlated with more warm colors in the artist's paintings.

"Early artists created an inadvertent record of climate change. That began to change around the mid-20th century when artists deliberately started picturing the explosion of the human footprint," William L. Fox, director of the Center for Art + Environment at the Nevada Museum of Art, told The Scientific American.