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Colours in sunset paintings show air pollution levels over 500 years

by Samuel Mintz | Thomson Reuters Foundation
Tuesday, 1 April 2014 11:15 GMT

Digitally compressed paintings produced by colourist P. Tetsis at the island of Hydra in Greece in June 2010 during and after the passage of a Saharan dust cloud. The painting on the left shows more dust in the atmosphere than the one on the right. At the bottom are photos of the landscape, taken halfway through the painting process. Images: P. Tetsis (paintings) and C. Zerefos (photos)

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Ratios of red to green in historic art matches levels of dust in the atmosphere, researchers say

LONDON (Thomson Reuters Foundation) – In a poetic coming-together of art and science, researchers have linked the colours used in paintings of sunsets throughout the last 500 years to atmospheric pollution levels at those times. The work could be used as a new tool for analyzing the environment in past centuries, when modern-day instruments were still far from being invented.

Red and green are the key, said lead researcher Christos Zerefos. The higher the ratio of red to green in the paintings, the larger the amount of aerosols floating in the atmosphere – something that in the past was usually the result of volcanic eruptions.

According to a press release from the European Geosciences Union, “skies more polluted by volcanic ash scatter sunlight more, so they appear more red.”

The researchers also did a modern experiment to check their findings.

“We experimented with a famous colourist,” said Zerefos. The man was not told about the experiment; instead “we asked him just to paint. We knew that there was a Sahara dust event coming from conventional forecasting tools that we use in meteorology, so we let him paint, and it turned out that without him knowing, he painted red-green ratios proportional to the aerosol.”

The paper, which was published in the journal Atmospheric Chemistry and Physics, could help point to ways to examine atmospheric aerosol levels in the future as well as the past. Researchers now hope to bring in a neuroscientist to help to look at how the brain registers colours.

“What we plan to do for the future is to collaborate with someone from neuroscience, and see what experiment he can tell us to make so that we can really get more information on how the brain perceives the ratio of colours, not the colours individually.”

Samuel Mintz is an AlertNet Climate intern.

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