Tirupati, Jan 8 (UNI) The efficacy of cloud seeding resorted by various States to induce rains during failed or poor monsoon seasons is being studied through a national experiment coordinated by the Indian Institute of Tropical Meteorology in Pune. It could take at least three years for Met experts to conclude whether cloud seeding helps triger rainfall whenever the monsoon fails according to an expert participated in the recently held 104th Indian Science Congress here. The experiment taken up in two arid regions of Maharashtra and Telangana to study the efficacy of cloud seeding when the monsoon plays truant. The results of ongoing experiment could help either increase this technique to quench the thirst in parched areas, or identify other methods to overcome shortage. Institute Director R Krishnan said two aircrafts and a host of instruments were being used to determine the effect of cloud seeding. Experts from various organisations including the Indian Space Research Organisation (ISRO) were contributing to this unique study, he added. He said deforestation had been found to be one of the major reasons for monsoon failure. Nearly 40 to 45 per cent of forest cover had been lost over the last two centuries in South-East Asia. These forests have given way to agricultural fields thus resulting in loss of incoming radiation. Besides this the El Nino factor and several internal issues had severely impacted the monsoon showers. Mr Krishnan said the monsoon was decreasing over Himalayas over the last 200 years, resulting in reduction in formation of ice during the winter, and subsequent inflow of water into rivers like the Ganga. Last year, the monsoon was expected to be normal but fell short because La Nina did not develop as expected. UNI CNR MSP CS 1333