A team of scientists from Stanford University in California analysed data on rainfall during the Indian monsoon gathered by the Indian Meteorological Department and other sources over a 60-year period, comparing peak monsoon rainfall patterns during two time periods – 1951–80 and 1981–2011 – and during the peak months of July and August.
The results suggested that although the average total rainfall during the monsoon season has declined, rainfall during the peak monsoon months has become more variable, with increases in the intensity of wet spells and in the frequency of dry spells.
‘The statistical techniques show that the changes in these characteristics are robust and that these changes are unlikely to happen purely by chance,’ said Deepti Singh, the study’s lead author.
‘There are many predictions that global warming should cause heavier downpours and more frequent dry spells,’ said one of the study’s authors, Noah Diffenbaugh. ‘That’s what we’ve found here, but India is a complex region, so we want to be sure before we point the finger at global warming or any other cause.’
This story was published in the June 2014 edition of Geographical Magazine