State of the Planet

News from the Columbia Climate School

, , ,

The Uncertainties of Groundwater and Climate in India: An Interview with Chandra Kiran Krishnamurthy

Since he arrived at the Columbia Water Center at its founding in 2008, Chandra Kiran Krishnamurthy has been unswervingly focused on two questions. First, how will groundwater depletion and climate change affect agriculture in India? And given the dire nature of the crisis, what can we do to help people adapt?

It’s a challenging question. By all accounts, sub-surface supplies throughout India teeter on the edge of full-blown crisis. Sixty percent of irrigated agriculture in India depends on pumped groundwater, much of which is non-renewable or being used faster than the recharge rate. Uncertainty about how climate change will affect weather patterns over the country only complicates matters.

A recent PhD graduate of Sustainable Development at Columbia University’s School of International and Public Affairs (SIPA), Chandra has taken key role in developing Columbia Water Center’s PepsiCo Foundation funded Punjab groundwater project, which seeks to test and implement inexpensive water saving measures for farmers. He recently defended his dissertation and will be doing his post-doctoral studies in Sweden.

In this interview, Chandra talks about the impact of climate change on Indian agriculture and figuring out how the uncertainties surrounding groundwater depletion drive farmer behavior.

Chandra Kiran Krishnamurthy

Can you describe what you’ve been working on here at the Columbia Water Center?

One focus has been on developing the big picture understanding of how have rainfall extremes over India changed in the last 50 to 100 years. At the same time, I’ve also worked at the local level, looking at very specific issues related to groundwater and agriculture in Punjab, working with Columbia Water Center on that part of their India project.

For that project, the questions we’ve been trying to answer are: first, what has been the trend of groundwater depletion in Punjab and how did we get to that point, and second, how will that depletion translate into livelihood changes in the future?

Then, given our understanding of this, the question was, what can we do? What can a center – the Columbia Water Center – do to assist in thinking of solutions?

In most of these resource management cases, large-scale solutions are not a mystery. The question is how to get to what we know is a good solution in a way that is not just politically but economically feasible.

So we focused on two experiments that would help us understand the characteristics of a solution, how they would or would not work in the real world, and what else should be done to be sure that thee solutions are real ones–and if they’re not, what could we learn from that?

The tensiometer, an inexpensive device that measures soil moisture to help rice farmers irrigate more efficiently.

Do you think it was successful?

I would say we have been successful in the sense that we have demonstrated substantial water savings with very little financial investment.

The key question is, will this approach work over time and to what extent is it scalable over space? And what kind of savings can we reach? We are still grappling with these bigger issues. We are hoping to continue the experiment on a larger scale, to really answer those questions.

Your dissertation is called “Essays on Climate Change and Indian Agriculture” Can you talk about that?

The first question that I looked at is the probable impact of climate change on agricultural yields in India. The main result is that the impact of climate change on agricultural production in India depends very crucially on which season one is talking about. If one is talking about the summer growing season, then my results indicate that there are unlikely to be substantially large impacts in the medium term.

In the case of the winter season, my results indicate unambiguous declines in yield for the medium term.

The next part of the dissertation is: how have extremes of rainfall changed over the past hundred years over different regions in India? Here again the picture is mixed; the answer, it turns out, depends on which measure we’re talking about, with some regions of India are experiencing an increase, and some a decrease. The main message really is that one has to be nuanced when one tries to project, or even contemplate, how these things might change under an evolving climate.

Finally, I have a more conceptual paper that is trying to understand–in a developing country scenario–how an individual farmer can optimally manage a groundwater reservoir, depending on a variety of assumptions about the reservoir. We’re basically trying to understand decision-making under uncertainty, in the context of groundwater management.

In this context there are two sorts of uncertainty. There’s the natural source of uncertainty, which is recharge, and then there is the human source of uncertainty, which is price. In certain settings it would be good to know which source of uncertainty is most important. Can we ignore the natural uncertainty because the human uncertainty is so large that it damps any other source of uncertainty? When can we and can we not ignore a certain source of uncertainty?

It turns out that when there is more than one kind of uncertainty, analysis is really, really complicated. It’s not even clear what behavior is intuitive in this case, because there is nothing obvious.

Suppose, for example, that one increases the uncertainty of the price of non-rice crops—what is the farmer’s response? Would the response be to always plant rice, and therefore extract more water? Or would it be to alternate rice with the other crop, in spite of price variability?

What kind of an effect on farmer behavior would putting a price on electricity have? What kind of price would have to be put to effect farmer behavior to achieve better groundwater outcomes? Is putting a price on electricity even necessary or sufficient to achieve the outcome we desire?

Groundwater pumping in India. Electricity for irrigation is subsidized giving farmers little incentive to conserve and complicating decision-making.

If variability in price is really what’s driving the entire system, then interventions that focus on this element – like insurance, or contract farming – are likely to be most important.

Especially from a policy perspective, it is very important to understand how changes in certainty affect the farmer, because this will help us think through and understand the full implications of a policy prescription.

This part of my dissertation really develops a framework that helps answer these questions. Hopefully in the next couple of years I will answer specific questions with this framework.

Columbia Water Center demonstrates research-based solutions to global freshwater scarcity and climate-related water risks.  Follow Columbia Water Center on Facebook and Twitter

Banner featuring a collage of extreme heat images.

Recent record-breaking heat waves have affected communities across the world. The Extreme Heat Workshop will bring together researchers and practitioners to advance the state of knowledge, identify community needs, and develop a framework for evaluating risks with a focus on climate justice. Register by June 15

Notify of

Inline Feedbacks
View all comments