Why Earth Systems Science?

Since my last post, I have switched jobs and moved.  Now that all of the whirlwind of moving to a new place, searching for a job, going through the entire interview process, negotiating salary and benefits, proceeding through the introduction to the job, and getting settled into both a new apartment and a new job has ceased, I have a moment to think (and not be plagued by writer's block).  Interestingly, it was a conversation this weekend which reminded me of a common question over the past six months:

"Wait, you majored in the science of Earth systems?  What does that mean?"

Of course, this sort of question would invariably lead me into either (a) an extremely short, I-study-everything-Earth-type response; (b) a simple response of "Well, really, I focused on meteorology and atmospheric science" that cleared things up without really touching on what I really studied; or (c) a very lengthy discussion about what Earth systems mean, the processes involved, and (practically) what I would do with my degree.  Most circumstances called for option a or option b since often I did not have the time to dedicate to a full explanation.  Alternatively, the person asking was not particularly interested in the full details:  They just wanted a better picture about what sort of science I understood.  However, on the occasion where option c was available, I started explaining my studies and often was rewarded with an excellent conversation that delved into the science of my degree and even the philosophy or culture behind it.

So, what are Earth Systems, and why do they warrant a specific degree rather than simply taking a geology degree or an atmospheric science degree?

Earth, as the scientific community is becoming aware, is a very, very complex world.  We could study things in concrete disciplines, with black-and-white divisions—indeed, we did for a very long period of time.  In a way, it was precisely because we still had so much to understand that these divisions worked.  Without knowing, for example, that limestone is different than granite and that the two formed under different circumstances, we would never have been able to make the connection between the tiny forms of life that left layers of calcium carbonate at the bottom of the ocean and the rock formations we study today in geology.

Earth as a complex system is often broken up into different sub-systems, called "spheres", when it is studied.  Each sphere is a focus of study that is very specific.  Some people define more spheres than I do, others less, but that is the nature of a complex system.  For my purposes, the definition from my degree works fairly well, as long as I acknowledge that other people may identify other systems.  The five I identify are the atmosphere (meteorology/climatology), the lithosphere (geology; note that I am not using the meaning of lithosphere that is a layer of Earth, but rather the generalized term for rock as we used it in my degree program—another term would be the geosphere), the hydrosphere (both fresh- and salt-water), the biosphere (life), and the cryosphere (ice).  All of these spheres are highly interconnected, with changes in one sphere affecting other spheres.

So, a simplistic example:  a volcanic eruption.  A volcanic eruption is within the lithosphere.  However, the spew of ash and other particulates into the atmosphere as aerosols affects the atmosphere.  As the atmosphere carries the ash elsewhere, the aerosols can cause cloud formation and rain over other areas of the world, which can affect the biosphere and even the hydrosphere.

Now, back to those spheres.  Since they all affect each other, the spheres are said to interact with each other.  Often, this involves feedback mechanisms, which are active areas of earth systems science research.  A feedback mechanism is actually a common element in many different areas of science.  More on that in a later post. The important point in this discussion is that these systems are highly interconnected, and small changes can multiply into huge changes in certain circumstances. That fact is why many scientists are referring to the study of Earth as the study of Earth systems. If we are to understand how the Earth works and how what we do affects the world around us, we need to look at Earth as a series of sub-systems with extremely complex interactions. Decisions need to be made with that high level of interconnectedness in mind; weighing all the effects of our actions as a species will require more awareness and more detail than that under which we have been operating as a society. To take on a very controversial topic, the use of fracking techniques, for example, will need to be considered in light not only of our interaction with the geosphere, but also with the hydrosphere in the form of groundwater and aquifiers.

With all of the debate over climate change at the moment, perhaps this may—however obliquely—shed light on why scientists cannot say with any certainty what will happen if we, for example, reduce fossil fuel usage. The system is so complex, the sub-systems so unique, the interactions so unknown, that all we may do is take our limited knowledge and forecast forward from there. A computer calculating the future climate under certain conditions can only give us a forecast that is as good as the knowledge we have to set up the current parameters. Computers, as many of the programmers I know would say, can be remarkably wrong when our initial input is incorrect even by a slight amount.

Hence the importance of a degree that looks at all of the Earth systems, one which trains the alumni to understand that every component of the system is dependent on other components of the system. One which emphasizes the need for learning each sub-system even while focusing on one sub-system and its specific interactions with other sub-systems. It is a natural evolution, in my mind; once we began to understand the specifics of each sub-system on its own, we needed to begin to widen our view to encompass interactions between sub-systems if we ever hope to get a grasp on the system as a whole.

This whole post is only a small piece of the conversation I have started as part of my option c response to the “What is Earth systems science” question. It does not touch on the more involved meanings of Earth systems science (that would be the length of a book or even a series of books!), all of the detail of processes involved (which will likely appear as posts later down the line), or even what I will do with my degree (there are a lot of choices). I did not get into the philosophical discussions—which pull in the history of science, cultural perceptions, and even social norms—that arise when I discuss the implications of my degree intellectually or academically. However, I think this provides a relatively concise manifesto in support of my field along with a short introduction for anyone considering the field itself. Ask questions in the comments, though, if you find something in need of clarification!