06 Jun Rev. Tom VandeStadt — “Crossing Planetary Boundaries”
In January of this year, the Journal Science published the latest findings of the University of Stockholm’s Stockholm Resilience Center, a research institute that in 2009 developed the concept of Planetary Boundaries. In this model, scientists view the earth as a vast system of systems—the interaction of land, ocean, atmosphere, and life—that make up the Earth System. Nine “boundaries” represent specific systems and processes that regulate the stability and resilience of the Earth System as whole.
These boundaries also represent limits that, if transgressed, increase the risk of making the earth less hospitable for human habitation. According to lead author, Professor Will Steffen, “Transgressing a boundary increases the risk that human activities could inadvertently drive the Earth System into a much less hospitable state, damaging efforts to reduce poverty and leading to a deterioration of human well-being in many parts of the world, including wealthy countries.”
According to the eighteen international scientists that conducted the latest research, humans have now transgressed four of the nine boundaries: climate change, biosphere integrity, land systems, and biogeochemical cycles. Scientists consider two of these boundaries, climate change and biosphere integrity, to be “core boundaries.” Significantly altering either of these “core boundaries” is particularly alarming.
With climate change, the earth has now surpassed the 390 parts per million CO2 mark in the atmosphere. For the entire month of March, the earth averaged over 400 ppm. Preindustrial levels were 280 ppm, and scientists warn that we must reduce CO2 to 350 ppm. We have also reached a point where the loss of summer polar sea ice is almost certainly irreversible, which could help drive the Earth System to a warmer state and contribute to sea level rise. Scientists question how long we can remain over this boundary before large, irreversible changes become unavoidable, changes that produce major threats to human well-being.
Loss of biosphere integrity includes the mass extinction of species currently occurring throughout the earth, and the loss of biodiversity through the wholesale destruction of eco-systems, particularly forests. The main drivers pushing the loss of biosphere integrity are the human demand for food, water and natural resources, driven particularly by high consumption levels in the rich developed countries, and by rapidly expanding middle classes in nations like Brazil, China, India, Russia and South Africa.
With regard to land systems, humans are “developing” land by converting it to human use all over the planet. These lands include forests, grasslands, wetlands and other vegetation types. Again, the loss of forests is of particular concern because forest destruction increases species extinction, and by removing forests from the face of the earth we remove important carbon sinks that soak up atmospheric carbon.
Finally, humans have significantly altered the biogeochemical cycles of nitrogen and phosphorous, mainly as a result of industrial and agricultural processes. Of particular concern is the increasingly heavy use of fertilizer in industrial agricultural production and the impact this has on soil. Furthermore, a significant amount of human-applied nitrogen and phosphorous ends up in the earth’s waterways and oceans, pushing marine and aquatic systems across ecological thresholds of their own.
Last month, I shared three different theological or spiritual models from which Christians can draw to respond to our growing ecological and climate change challenges. All three models—Creation Care, Eco-Justice, and Eco-Spirituality—can provide resources to us as we reflect on our response to our troubled relationship with the earth. This month, on June 14th, Chris Searles, a long-time environmental activist, will offer a presentation to our church that addresses a number of the boundary-transgressing issues outlined above. In particular, he’ll address the loss of biodiversity and species extinction, with an emphasis on tropical forests. And he’ll share with us how people around the globe are making the concerted effort to preserve forests in an attempt to address biodiversity and species extinction, and to maintain each forest’s vitally important function as a carbon sink. Most importantly, he’ll offer us an opportunity to participate in these efforts. I’ve seen his presentation twice, and besides being very informative, it’s both disturbing and hope-inducing. I hope you can make it on June 14.
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Learn more about Rev. Tom's church, the Congregational Church of Austin, UCC: http://congregationalchurchofaustin.org
Learn more about Chris Searles' project, BioIntegrity: http://www.biointegrity.net
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