London, November 15 : Scientists have warned that the presence of smog over India is an indication that the country is getting lesser amount of sunlight.

Padma Kumari and her colleagues at the Indian Institute of Tropical Meteorology in Pune reckon that the country is getting about five per cent less sunlight than it did 20 years ago.

The researchers studied data from the India Meteorological Department, and measured differences in solar radiation at 12 stations across the country between 1981 and 2004.

They observed that the amount of solar radiation reaching India's land mass reduced on average by 0.86 watts per square metre each year. The decline was greater during the 1990s than the 1980s.

According to the study, the country is getting lesser sunlight due a rise in particle pollution linked to industrialisation.

The researchers also blame Western countries for “solar dimming”. They say that the smog produced by the US and Europe during the 20th century spread worldwide and was responsible reduction in the amount of sunshine reaching the Earth.

However, they have also acknowledged the fact that clearer skies returned when the West cleared up its smog pollution in the 1980s and 1990s. The researchers call this phenomenon "global brightening".

Since the global brightening was accompanied by an accelerated rise in global temperatures, the scientists believe the cooling effect of smog may be providing India with protection against global warming.

The researchers also noticed that solar dimming over India was lessened during the monsoon season because the torrential rains brought the fine particles back down to Earth, allowing more sunshine to get through.

They are currently in the process of updating data in the Global Energy Balance Archive, which tracks sunshine levels at 2500 sites worldwide, reports New Scientist magazine. (ANI)