LONDON: Contrary to popular perception that glaciers are melting faster the world over due to global warming, a new study says that Swiss glaciers were melting even faster in the 1940s when temperatures were lower.

Significantly, ETH Zurich researchers attribute the melting of glaciers in the 1940s to a lower level of aerosol - a suspension of fine solid particles or liquid droplets in a gas - pollution in the atmosphere.

The increase in winter snow and melting glaciers in summer have been measured at heights of 3,000 metres, on the Clariden Firn, the Great Aletsch glacier and the Silvretta glacier, without interruption for almost 100 years.

Matthias Huss used this unique range of measurements to examine how climate change in the last century affected the glaciers, as part of his doctoral dissertation.

His work was supervised by Martin Funk, professor in glaciology at the Laboratory for Hydraulics, Hydrology and Glaciology ('VAW') ETH Zurich, who co-authored the study.

The research team took into account the solar radiation measured on the earth's surface in Davos since 1934.

They arrived at their findings by calculating the daily melt rates with the aid of climate data and a temperature index model, based on the half-yearly measurements on the glaciers since 1914.

These results were then compared with the long-term measurements of solar radiation in Davos, says a release of ETH Zurich.

Studies over the past two decades have shown that solar radiation varies substantially due to aerosols and clouds, and this is assumed to influence climate fluctuations.

The new study was published in Geophysical Research Letters.