Although a normal monsoon has been forecast for South Asia this year, and rains have begun normally in many parts of the region, people are still anxious about the rainy season that lasts for four months.
Their anxiety has to do with the uncertainties surrounding the timing of the monsoon in recent years.
While the debate continues over the role of climate change, scientists have also been looking at the possible role of soot and urban smog pollution in disrupting this weather system.
The uncertainties surrounding the monsoon have mainly affected agriculture, resulting in a rise in food prices.
In the past decade, a number of monsoon seasons saw lower than average rainfall in some places. Some areas were hard hit by droughts while other areas were flooded with unusually heavy and torrential rainfall in a short span of time.
The variability and the erratic pattern has begun to emerge in some parts of the region this year already.
Soot includes particles of so-called black carbon from the incomplete combustion of fossil fuels, wood and biomass burning.
Smog consists of air pollutants in the lower atmosphere, including troposphere ozone, a powerful greenhouse gas.
Several scientists have over the years said that increased concentrations of black carbon and troposphere ozone could be disturbing monsoon patterns.
