Questions to ask oneself before choosing an interdisciplinary PhD

Why an interdisciplinary PhD in Environment/Sustainability? 

I will begin with why I made this choice.  I was applying on the back of a bachelor and master of science degree both in Mech Engg and about three years experience working as an Engineer in the research and development division of large private corporation. I was working on emerging energy technologies such as fuel cells and microturbines for distributed power generation mainly from an engineering standpoint but then happened to get assigned a project focussed on the business case for these technologies. This project really spurred my interest in issues related to cost of energy and policies to reduce pollution. I applied to an interdisciplinary PhD program with just a broad motivation to work on clean energy and not being able to articulate much more than professing that I felt it was my responsibility to work towards making the world more environmentally friendly, yes it was that corny and am embarrassed at my naivete.  

But while it has luckily worked out for me, my resume perhaps compensated for my naivete, I actually feel a bit more clarity as to why you really want to go this route, and what you want to do with it wouldn't hurt for this a big leap. You don't quite need to know what it is you want to research as much as what type of thinking and analytical skills you really want to learn. I would recommend asking yourself the following questions

1. Which among the two is the key motivating reason for you?

• Intellectual curiosity: A pure thirst for an understanding of why things are the way they are (in a scientifically/empirically verifiable sense) or how they ought to be/what we ought to do (from a given normative/ethical standpoint).  To me this is knowledge for knowledge sake or for your own intellectual satisfaction. We owe many of the scientific breakthroughs and innovations to this sort of drive - in basic physics, chemistry, biology etc. Only with intellectual curiosity will you really try to get to the bottom of the problem to understand the fundamental causes. In the context of sustainability, this involves asking fundamental questions such as what is our ethical responsibility to the poor and the future,  how do we make decisions under uncertainty (not just risk but fundamental ignorance), how do we discount the future, what types of new institutions we need etc. There are innumerable fundamental questions which more easily fall under philosophy, economics, political science, sociology, climate science etc. or even mathematics. If what drives you is pure intellectual curiosity, a PhD is for you without a doubt, at least if you want a traditional career and accepted forum to pursue this. As to whether you want to do an interdisciplinary PhD requires you to dig a little deeper into your motivations. I say this because, I often find myself craving for an even deeper understanding of say, ethical theories, physical or biological laws,  statistical theory etc. Secondly, I find sustainability research drawing on these more than contributing back to these traditional areas of inquiry, or at least that is my limited understanding based on what I read. It is of course possible to come out of an interdisciplinary program and make fundamental contributions to human understanding but there are more straightforward trajectories for that while remaining motivated by Sustainability. I say this because at its core sustainability is concerned with Ethics and it builds on a solid understanding of human behavior, political and economic systems, basic workings of nature and sustainability research is about taking these reductionistic understandings and saying something that is more than its parts. 

• Passion for impact on environment and society: I see this as absolutely necessary but not sufficient for while you can make a great impact armed with a PhD, you dont really need a PhD for this. In fact advanced degrees could even be a hindrance, fo at its core this is about learning to work with people to get some change going on the ground - by informing individuals, or working with or in businesses, non-profit institutions, and government and you need a capacity to translate science and be an effective communicator, organizer or manager. However, it is true that a PhD lowers the barriers to entry to various institutions through which you can impact on sustainability short of becoming an entrepreneur yourself. This is why a desire to contribute to change is necessary for without this motivation, why bother with  a PhD in Sustainability. I am bit more cautious about enthusiastically encouraging you to do a PhD if your primary objective is bringing about this sort of change. Also a desire to have an impact on the practice of Sustainability can make one impatient not wanting to take the time to learn the boring and painful and I know this because there are way too many classes that talk of lofty things, critiquing everything people, businesses and government do  while requiring little rigorous work or critical thinking. Unfortunately,  academics can often be  arm-chair or ivory-tower critics who themselves lead highly unsustainable lifestyles (flying to conferences, going away to a secluded place to think and write) ensconced in the security of assured and well paying jobs while exhorting students to go and enact change on their behalf. The least I could do is be authentic if I cannot walk the talk. But even if one walks the talk, they would be wrong in expecting others to be able to follow their path. Somewhat recursively, leading a sustainable life oneself is necessary but not sufficient to preach sustainability. 

At one level with an interdisciplinary PhD in environment this is also about asking yourself why do you want to be a generalist? I recall a book I read (more precisely, listened to the audiobook) Range: Why Generalists Triumph In A Specialized World by David Epstein. It doesn't hurt to know that Roger Federer is used as an example of someone who started off learning many sports before settling on tennis or that many nobel laureates while best at one thing are also very good at a few other things. Seems not really that striking but it is the simplest of things that we fail to tell ourselves when we need to and go looking for more profound stuff.  

As for me it was a combination of desire to switch career from engineering to working on environmental issues and since I already had a Masters it had to be a PhD, nothing more profound or no lifetime passion, none of that. But if you ask me both having a thirst for knowledge for knowledge sake and a desire to have an impact is ideal.

This brings me to a second question you should ask yourself

2. What would you like to do post PhD? 

A PhD in sustainability can help in each of the three different types of career's below which I rank order in terms of the returns to investment in a PhD in Sustainability. And by returns I don't mean financial returns (the order will be reversed if we are talking purely financial returns)

• Academia - research and/or teaching 
• Research non-academic 
• Non-research  

I personally feel this is a great time to get an inter-disciplinary PhD if you are interested in an academic career. We are not at a point where we can say the world has one too many generalists.  Also the number of opportunities in academia for interdisciplinary studies is growing (demand). But I suppose the supply of graduates is also growing faster relative to demand and so getting good academic jobs could get tougher. However, this supply and demand argument is less straightforward for there is so much room to differentiate yourself that if you are good you wont be easily comparable to others. If oil companies can brand a commodity like gasoline, I will find a way to differentiate yourself. I had earlier written about my approach and good fortune in choosing an academic career with an interdisciplinary PhD here

An interdisciplinary PhD is also very good for teaching Sustainability or research in non-academic settings. And last but least it can hold immense value in non-research careers in multinational corporations, think tanks, governmental organizations and multilateral institutions such as World Bank etc.

I would like conclude with a few cautionary notes. One is that as exciting and important as Sustainability sounds, coming up with something new, backing it up with evidence, and accomplishing it all in 5 years, is not an easy task. It really requires the discipline to very quickly shed any inhibition of wanting to change society through a dissertation and take up some thing that is small and become really good at it and I assure you it will not be insubstantial in effort or impact. I think it is important to be humble while wanting to make a mark. 

To quote the really wonderful Paul Eddington from my all time favorite political satire Yes Minister - "A journalist once asked me what I would like my epitaph to be and I said I think I would like it to be 'He did very little harm'. And that's not easy. Most people seem to me to do a great deal of harm. If I could be remembered as having done very little, that would suit me." - Excerpted from LINK