History of the Future: Interstellar

It is great to be here with you all tonight and to celebrate Earth Day with you.

Most of Interstellar takes place far away from Earth. And yet, I find the movie a fantastic opportunity to reflect on our planet. I want to share with you a few thoughts on my work as a biologist on earth, and how this colors my perspective on Interstellar.

You’ve seen the road signs:
Dust storms may exist. Zero visibility possible.

I came to truly understand the meaning of these signs the day that I drove to southern New Mexico to start a new job. My car was packed with everything I owned that wouldn’t go in the moving truck due to being flammable, liquid, or alive. It wasn’t a great time to spend hours on the side of the interstate, wind howling, the promised near zero visibility, and my cats yowling in the backseat. But this was early in my days as a desert ecologist – I didn’t yet appreciate that a few hours is a short dust storm or how lucky I was to have a well sealed car.

I’ve since built my career studying the ecology of some of the world’s least hospitable deserts. I’ve had the opportunity to stop and look at these systems closely, realizing how full of life they are even when they look barren and devoid of life on the surface.

In the hyperarid Namib Desert of southern Africa we work on the bizarre Welwitschia plant – which produces only two leaves that might live for 1000 years and they grow continuously like a beaver’s teeth – somehow it continues to capture light energy through photosynthesis even if it has been a few years since the last rain.

Or on the windswept Namib plains there are almost no plants, and much of the light energy capture is done by hypoliths – these are communities of photosynthetic micro-organisms that live and capture solar energy under rocks. The sun and wind are so harsh that the microbes can’t live on the soil surface like they do here in the Sonoran Desert, but life is glorious under the shelter of quartz rocks that are just translucent enough to let a little bit of sunlight through for photosynthesis.

In these conditions I’ve lost days on end of planned fieldwork while the wind howled outside. I’ve lost more than a few sensors and samples to being covered by shifting sands, while also learning the best ways to clean dust out of electronics. Fortunately only one time was I careless
enough to let one of my precious data sheets get carried off in a dust storm.

So as we see the future Earth envisioned in Interstellar, I have a visceral reaction to the dust storms … I feel the dust itching in my scalp and ears, feeling like it will take a week of showers to feel clean again. I look at the small mountains of dust on the windowsills in the farmhouse and I wonder if it is strategic to clean them now, or will another dust storm just coat the house again tomorrow?

But much as I loathe the feeling of sand exfoliating my face, I have also come to realize that dust is one of the factors that shapes deserts. Deserts cover nearly half the world’s land surface, but they’ve been the research underdog for a long time.

We’ve struggled to understand and predict biological patterns in deserts. I think this is in part because we have expected desert processes to be governed by the same general rules as wetter systems, but just more limited by water. Recently, some collaborators and I have concluded that in many ways deserts operate under an entirely different set of rules.

Dust is a key player in a few of these desert rules. For example, when wind move dust around, it redistributes mineral nutrients used by plants, concentrating these resources in certain areas and leading deserts to be much more spatially variable than wetter locations.

Similarly, wind moves dead plant material along with dust, leading to burial of the plant material in locations where it is more readily transformed by micro-organisms.

And these desert rules extend beyond dust.

Have you noticed how dense vegetation can be underneath trees in deserts? One reason is that deep-rooted plants, like many desert trees, draw water upwards through their roots. Once it gets toward the surface the soil, physical properties can lead to water being inadvertently released from the roots into the surface soils. This is unfortunate for the trees, but it sustains the typically shallow-rooted plants that are living underneath the deeply rooted trees.

Dominant cooling processes also differ in deserts, where uneven canopy structure and low water availability lead to substantial convective air cooling. This contrasts with forests where uniform canopies and high water availability lead to evaporative cooling.

The thing about these desert rules is that they’ve been really helpful for my desert ecologist colleagues and me as we strive to understand and predict ecological patterns in deserts. But, we’ve also come to realize that – while uniquely important in deserts – these processes sometimes occur in wetter systems. When climate change pushes wet systems into extended dry conditions, desert rules can kick in.

In the scientific paper where we outlined the idea of the desert rules, we discuss examples of wetter systems operating under desert rules.

One of these examples looks to me like the opening scenes of Interstellar. In the movie, we see a struggling unirrigated agricultural system. Climate, blight, and other forces unknown to us have changed the nature of this system. Crop productivity is on edge and human livelihoods are threatened.

In the paper, our struggling corn fields are in northern Europe in the 2018 drought and heatwave.

Both the real and imagined systems have switched to desert rules – to understand how these systems are operating, we have to use lessons learned in deserts.

As we meet the protagonists of Interstellar, humanity is at a crossroads … the planet that they know has changed dramatically and the future of human civilization is under threat. The rules that worked in the past are no longer in place – what can they do?

The different perspectives on what to do in the time of planetary change is an important underlying theme in Interstellar. We see this very clearly in the scene in the principal’s office. To save humanity is the best bet to hang our hopes on educating future farmers?

Our protagonists elect to hang their hopes on finding a habitable exoplanet in the vast universe.

I’m rather fond of earth, so if I were in the imagined earth of Interstellar, I think I’d go with the farmers – but also work to see that the farmers were backed up by a cadre of scientists, land managers, and a thoughtful community – to understand, mitigate, and adapt to changing circumstances – with an understanding that the rules for how ecosystems operate might change through time and we need to be creative in our thinking.

Human curiosity drives us to explore, and the universe has no end to fascinating possibilities. We know that humans can go to the moon. Humans will go to other planets in our solar system and perhaps beyond.

We’re on an incredibly unique planet where luck and millions of years of evolution have collided to make Earth habitable, beautiful, and diverse in many different ways – from our driest deserts where photosynthesis happens under rocks to our tallest rainforests.

Are there other planets out there that could harbor life? I have no reason to think that there wouldn’t be and I’m intellectually curious to know what that life looks like and under what rules it operates.

We have challenges on earth, including issues that may threaten the future of life on earth as we know it. But we don’t want to find ourselves having to make the choices faced by the humans in Interstellar, or to gamble with the incredibly low odds of trying to find another habitable planet in a vast universe. Fortunately, I believe that there is no reason that we should need to take this gamble. We have a biodiverse planet with organisms adapted to endure against incredible odds.

On top of that we as humans are fortunate to have logic, problem-solving ability, scientific knowledge, and compassion. In comparison to interstellar travel, our earth-bound challenges seem to me to be pretty simple to solve, although we might need to have open minds to consider different rules. We can sustain life on this unique and fascinating planet if we put our minds to it.

Happy Earth Day and enjoy the show!