Lall-Post.jpg A leading expert on hydroclimatology and climate change adaptation, Upmanu Lall spends his days working on research projects in the areas of water resource systems analysis and flood/drought risk, and teaching both undergraduate and graduate students as the Alan & Carol Silberstein Professor of Engineering at Columbia University. In addition, Lall serves as the director of the Columbia Water Center, which combines research with policy to create sustainable models of water development and management that can be implemented on both local and global levels.

Here, Lall discusses how people are finally realizing that the climate is going to change and that we are going to be facing more floods and more droughts in the future; why, to work on water issues, one must also develop expertise in statistics, chemistry, ecology, and a number of other related areas; and how water scarcity will continue to increase and negate the efforts of those trying to deliver clean water to individuals.

What do you say when people ask you, "What do you do?"

I work with the science of water and climate, applying it to solve real world problems.

What new idea or innovation is having the most significant impact on the water sustainability world?

The understanding of climate and its influence on water. Many people are now in tune with the fact that the climate is going to change and that we are going to be in trouble either because there will be more floods or more droughts. This idea only goes so far, though, because there is much more to it than just climate change. The ocean and atmospheric conditions that determine flood and drought events need to be better understood, so that the predictive capability of floods and droughts can be improved. This will have a greater effect on people's lives whether or not average global temperature will be at some level in the future.

What's something that most people just don't understand about your area of expertise?

The question people often ask me is how can one person be working on so many different topics? It's nothing intrinsic about my personal expertise. If you are working on the water issue, you have no choice but to get into many different areas and seriously try to understand them. People don't understand that to work with water issues, you have to develop expertise in a number of related areas ranging from climate to ecology to statistics to chemistry and policy and decision making.

What's an emerging trend that you think will shake up the water sustainability world?

The fact that water scarcity will continue to increase and negate the efforts of those trying to deliver clean water to individuals. This is often not appreciated by the non-profit community trying to provide people water through individual small projects. This modus operandi is going to be upset because there is no attempt to control overall resource use. Examples are abundant in developing countries such as India where there's no regulation of groundwater withdrawal. Anybody can go and start pumping, unless they are very big like PepsiCo or Coca Cola. You may be able to provide someone water today, but it may be gone tomorrow.

In terms of safe drinking water supply, which is what many people are interested in, most of the technologies and methods we have used in the past are going to be supplanted by small-scale devices that are quite effective in terms of both energy use and the level of purification. We are not far from deploying those technologies, which can be as complicated and at the same time as simple to use as the refrigerator. The refrigerator is not a simple technology, but we have it and we use it. Water purification may be not very far from that.

What's a water sustainability trend that you wish would go away?

For the last ten to twenty years, there has been a lot of discussion about integrated water resource management (IWRM), and I think this is a distraction, because there is very little understanding of what that means in practice. It looks at all aspects of water use, at all the stakeholders involved in water use, for example, and weighs them equally. It doesn't recognize who has the power, or what the institutions are, or what the feasibility is of different future scenarios. I think the discussion about IWRM is moot. Rather than talking about integration as a theory, one needs to talk about what to do in reality, and this can translate into a few specific things in each place. Of course, one has to be thoughtful about the broader impacts of what one does to change the course of water, as well as what would happen if nothing is done to change the direction of water use and supply.

What's an idea you became fascinated with but that ended up taking you off track?

There are too many. It happens all the time, every day. To choose just one I would say chaos theory. The basic idea is that there really may not be any long-term predictability in any of the things that we usually talk about. One of the major goals of science is to say that things are predictable and deterministic; by finding the real law and associated data you can describe the future.

In chaos theory if you know what is going on today, you may be able to say something about a short period in the future, but after that, no. With even fairly simple systems you can start to lose predictability and all you may be able to say is something about the likelihood of certain types of events. Today, many scientists focus on linking large, complex climate models to water and ecology models, and may not have clear thinking as to what they can and cannot reliably expect to predict. At the same time, in a complex system, you may end up with interactions that lead to near regular recurrence of the same type of events, e.g., floods and droughts, in a certain region. That was fascinating and I spent quite a bit of time on it. I looked at it not just from a water or climate point of view, but at all kinds of systems in nature.

Who are three people or organizations that you would put in a Hall of Fame for your field?

First, the South Florida Water Management District, with Jayantha Obeysekera, and Tampa Bay Water, because academia creates knowledge, but one has to decide whether or not that knowledge is useful and how best to correctly apply it. These two organizations have done an amazing job in the U.S. They have been extremely forward-looking using academic tools and emerging ideas in the real world.

Second, the Harvard Water Program in the 1960s. They came up with principles for public sector investment in water. Today these principles are not considered to be functioning very well and in fact to be responsible for some of the ills, but at the time it was a benchmark.

Third, I'll say Leonardo da Vinci. He explored two main theories of how fluids flow and what can be done with them. Many of the things he worked on became the principles for design during that period.

What other field or occupation did you consider going into?

English literature, physics, and psychology.

What website or app most helps you do your job on a daily basis?

Gmail. It's available wherever you are. It's actually something that wastes most of my life. It's the communications piece of my life. I get papers to read, I send papers out.

What song's been stuck in your head lately?

Rat-a-tat. OK, that's not a song, but that's what I hear all day long from the keyboard

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