Teaching astrobiology in a sustainability course

Considering life in the universe gives undergraduates a broader perspective on sustainability.

Seth D. Baum. Teaching astrobiology in a sustainability course. Journal of Sustainability Education, February issue (online).

Full article: Available free online at Journal of Sustainability Education * Click here for the pdf.

Note: This paper is based on Penn State Geog 30. It extends the earlier paper Is humanity doomed? Insights from astrobiology.

Sustainability education typically focuses on sustaining life, ecosystems, and humans here on Earth. However, important insights come from considering life beyond Earth. This article presents several ways to teach astrobiology - the study of life in the universe - in an undergraduate sustainability course. The concept of habitable zones offers perspective on the temporal and spatial scales of sustainability on Earth and beyond. The prospects for long-term sustainability in the universe suggest expanded conceptualizations of sustainability, leading to a present-day focus on the risk of certain global catastrophes. Finally, the possibility of extraterrestrial life and the fact that none has yet been observed gives us new ways of thinking about our own lives on Earth. In sum, astrobiology offers an understanding of how our current sustainability challenges fit within the grander scheme of the universe. This understanding is of great value to the sustainability classroom.

Non-Technical Summary: pdf version

Background: Sustainability and Astrobiology Education
Sustainability commonly refers to the ability for human and/or ecological systems to be sustained on Earth in the face of natural resource depletion, environmental degradation, and other stressors. Astrobiology is the study of life in the universe, including Earth-life colonizing space and life that originates elsewhere. Both are interdisciplinary fields asking big-picture questions about humanity and its surroundings. While sustainability almost always focuses on life on Earth, much about sustainability can be learned from astrobiology. This paper presents several ways of building astrobiology into an undergraduate sustainability course, explaining the concepts and sharing resources including a syllabus, readings, and an essay question.

Where and When Can Life Be Sustained?
Life can only be sustained in habitable zones: places and times in which life can exist. Habitable zones exist across many scales. Habitable planets can only exist within certain zones of galaxies and solar systems. The Goldilocks Principle says that habitable conditions must be "just right". For example Earth can't be too close to or too far from the Sun, or else its temperature would be too hot or too cold. The same principle holds within Earth for humans: some regions are too wet (such as oceans) or too dry (such as deserts), although human technology can often find ways around these limitations (such as submarines).

Long-Term Sustainability
For how long can human civilization, or life in general, be sustained? Earth will probably remain habitable for several billion more years, until the Sun becomes too warm and large. If humans or other Earth-life can successfully colonize space, then we can survive for much longer, though the physics of the fate of the universe is not well understood. And so eventually, sustainability will require space colonization. But the several billion years remaining on a habitable Earth is a long time to achieve space colonization. For people alive today, the most important task towards eventual space colonization is preventing civilization-ending global catastrophes such as nuclear warfare, pandemics, disruptive technologies, and ecological collapse

Extraterrestrial Life
If there is extraterrestrial life, then perhaps life will be sustained in the long-term even if we fail to colonize space before the world becomes not habitable. So far, extraterrestrial life has never been detected despite how old and large our galaxy is, a predicament known as the Fermi Paradox. Several explanations exist for this paradox. One is that civilizations inevitably destroy themselves when they become sufficiently intelligent to do so, a frightening prospect for humanity. Another is that civilizations cannot sustain the rapid growth needed to reach distant corners of the galaxy. A third explanation is simply that there is no extraterrestrial life. We may be the galaxy's (or even the universe's) only shot at something truly special. These possible explanations feed into a suggested essay question: Is humanity doomed? In other words, is the current human population unsustainable?

Created 3 Dec 2012 * Updated 29 Jul 2013