Study of Sunsets to help in understanding global warming

A novel method of studying the effects of global warming with the help of old paintings of celebrated artists is being worked on.

The team, at the National Observatory of Athens, is using the works of old masters to work out the amount of natural pollution spewed into the skies by eruptions such as Mount Krakatoa in 1883. Reports from the time describe stunning sunsets for several years afterwards, as the retreating light was scattered by reflective particles thrown high into the atmosphere. By studying the colour of sunsets painted before and after such eruptions, the researchers say they can calculate the amount of material in the sky at the time.

The team found 181 artists who had painted sunsets between 1500 and 1900. The 554 pictures included works by Rubens, Rembrandt, Gainsborough and Hogarth. They used a computer to work out the relative amounts of red and green in each picture, along the horizon. Sunlight scattered by airborne particles appears more red than green, so the reddest sunsets indicate the dirtiest skies. The researchers found most pictures with the highest red/green ratios were painted in the three years following a documented eruption. There were 54 of these "volcanic sunset" pictures.

Amazing!