Why are the monsoons in India becoming more extreme?

They are becoming more extremes may be due to global warming and other climatic changes that are responsible to affect the environment badly..

Well one of the study's authors clearly states that we don't know: "The question is what is causing that climate change. It could be global warming; it could be some other forcing factors," Diffenbaugh added.

From the 2007 IPCC report, they state: "...observational data finds a significant correlation between ENSO and tropical circulation and precipitation such that there is a tendency for less Indian summer monsoon rainfall in El Niño years and above normal rainfall in La Niña years." https://www.ipcc.ch/publications_and_data/ar4/wg1/...

In the past 15 years, we have had a predominance of La Nina years so one would expect less extreme monsoon seasons. I guess that just highlights the fact that we really don't know.

In my humble opinion as a non-climate scientist I would suggest that there are climate cycles at work covering and/or changing over a much larger time scale than we have good data for. That always makes it difficult to extract a signal from the noise.

"Overall, they found that wet spells became more intense in the 1981-2011 period and that dry spells became more frequent but less intense."

Post hoc analysis looking at too short a time span and covering wet spells and dry spells in both intensity and length. HMMM! Do you realize that this barely covers a full PDO cycle?

So you pretend to be more knowledgable about science than I am.

Here is a question. If I look at 20 different variables for a statistically significant change at the 0.05 level, what is the chance I find one that is only statistically significant by chance?

If you want to plan for agriculture, then it is really simple. Farmers need methods of adapting to changes. The variation year to year far exceeds any changes they are going to see from AGW over their entire life. Consider this. The IPCC claims a 0.7 degree increase by 2050. What variation in local yearly averages do you imagine a farmer sees from year to year?

More water = more life