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Sunday, March 13, 2016

Managing our diminished biosphere

The question that he frames in all but words

Is what to make of a diminished thing

from The Oven Bird by Robert Frost

by Stephen Mulkey, The Environmental Century, March 7, 2016

There can be no doubt that our earth has been diminished by our presence. For the last 100,000 years we have built civilization mostly from the resources provided by the living ecosystems of this planet. Within the last 300 years, the pace has quickened exponentially as our exploding population has exploited the energy embodied in the carbon bonds deposited by organisms of ecosystems that thrived tens to hundreds of millions of years ago. Our industrial emissions and extractive use of resources have transformed our planet. There are no evildoers or sociopathic villains in this story. We simply did what a very clever social species would do to maximize reproductive fitness and build a civilization.
Obviously, this way of life is no longer in our best interests. A child born today faces the prospect of living in a world that is not merely vastly diminished but incapable of supporting our civilization unless we are able to make dramatic adjustments in our use of natural and human resources and rapidly bring new sources of clean energy online. Developing a sustainable relationship with our planet in the face of rapid ecological and climate change is the greatest challenge in the history of our species. Proactive adaptation to these changes is far less disruptive and expensive than is reactive adaptation, yet we are lagging in efforts to address our plight. We have little time remaining to assess and begin to adapt our living systems.
The preservationist conservation ethic that prevailed during much of the twentieth century is inadequate for this task. My generation of well meaning practitioners has walked in the footsteps of conservationists such as John Muir and Aldo Leopold, and worked diligently to preserve and restore nature. Unfortunately, the goals of restoration have sometimes been poorly defined and the expected outcomes of our management efforts are constantly changing. This is an ongoing and likely never ending discussion in conservation biology. The uncritical heuristic view of conservation treated an intact ecosystem as one that is more or less unchanging within a human lifetime. Looking back at my career, it seems as though my desire for moral action was at times channeled into the conservation movement without clear understanding of the natural and human drivers of the shifting baselines that define an ecosystem.
The changes that we have wrought are so vast that in many cases pure species and habitat preservation is simply no longer an option. With climate zones in rapid transition, the base of the food chain for many ecosystems is in the process of being disrupted over a decadal timeframe, which is a heart beat in ecological time. Thus, the species composition of many ecosystems is now in dynamic transition. As species move seeking better habitat, the definition of an invasive species becomes moot in many cases. In the face of such rapid change, restoring an ecosystem to some specified prior natural state is a futile activity.
Instead of maintaining the species composition of an ecosystem, at minimum we must focus on maintaining ecosystem form and function. We must work to maintain ecosystem services such as nutrient cycling and watershed integrity, which are crucial for maintenance of biodiversity and human well being. Active ecosystem management includes consideration of assisted species colonization, a controversial practice that raises issues of ethics as well as the potential for ecosystem disruption if done inappropriately.
I should be clear that I do not advocate abandoning endangered species to likely extinction. Instead, I am arguing for sophisticated, comprehensive management of ecosystems that include preservation of species and their precious genomes, but not necessarily in the context of the milieu of organisms where they have been during recent times. This will require us to become far more engaged with the principles of ecosystems science than is the current practice.
The potential for mismanagement is very real as we attempt to save not only form and function but specific species. Many academic ecologists will see this as a rationale for inaction. For some there will never be a time when we know enough to safely manage such complex living systems. I believe that we must act even if it means that we may make some mistakes, perhaps even big mistakes. This adds urgency to the need for focused research in the ecological sciences, rather than the continued collection of more little bricks for the edifice of knowledge. I hope that my colleagues, our professional societies, and funding agencies will continue to rise to this urgent challenge. Time is short.
Sophisticated proactive adaptive management of ecosystem form and function is not only crucial for maintenance of biodiversity, it is indispensable if we are to keep climate change within limits consistent with civilization. The living portion of the planet is both a greenhouse gas source and sink, and maintaining net positive greenhouse gas uptake requires ongoing active management on a global scale. We have much of the data necessary to support this task, but few effective management programs are underway and widespread.
The Intergovernmental Panel on Climate Change Fifth Assessment (IPCC AR5) reports that agriculture, forestry, and other land uses (AFOLU) account for about a quarter of all anthropogenic emissions. Although most of this was estimated to be due to deforestation, a disturbing new report in the journal Nature indicates that agriculture has driven the terrestrial biosphere to become a net source of greenhouse gases to the atmosphere. Reforestation accounts for recent trends in reducing CO2 emissions from AFOLU and the UN program known as REDD+ provides guidance on preserving forests for carbon balance, primarily in tropical countries. However, these new findings show that mitigating agricultural sources of methane and nitrous oxide will be required to significantly reduce emissions from AFOLU. The AR5 suggests that managing living systems for a combination of mitigation and adaptation can yield the best outcome in reducing the impacts of climate change over this century.
We are doing a very poor job of managing the emissions from the earth’s diminished living systems as they respond to the effects of climate change. Beetle infestations in the American West driven by warming and exacerbated by drought have led to massive fires of historic proportions. According to the World Resources Institute, in September 2015 enormous peat fires in Indonesia exacerbated by a severe dry season produced carbon dioxide and methane pollution equivalent to that of the entire daily output of the U.S. for each of 26 days. Similarly, recent severe drought in the Amazon basin has recurred at higher frequency than in recorded history leading to widespread tree mortality and impaired carbon uptake of surviving forest. We can expect increasing emissions from ecosystems as they are damaged by extreme weather, extended drought, flooding, storm surge along the coasts and other forms of disturbance that come with climate change. Impaired CO2 uptake and associated increased emissions from the earth’s living systems means that mitigation of fossil emissions must be ever more strenuous to overcome these positive feedbacks.
Within the recent decade we have become an urban species and generations of humans are living ecologically illiterate lives. Corporate and government decision making reflects a profound ignorance of the principles of ecology and sustainability. The role of ecosystems in supporting life is rarely appreciated and there is even less awareness of their role in regulating the temperature of our planet. Wholesale management of the earth’s ecosystems is necessary and urgent if we are to have a fighting chance at salvaging a livable climate through the end of this century. This will require federal, state, county, and municipal agencies to coordinate their activities and land use over at least a 50 year horizon. As the Paris climate accord has shown, international cooperation on such an unprecedented scale is challenging but not impossible.
Though diminished, the earth’s ecosystems remain utterly critical to our survival. We must actively assume the role of gardener in the garden, and like the gardener who plants perennials, we may not see the results of our efforts within our lifetimes. Never before in the history of our species has cooperation on such a grand scale been necessary. It is perhaps heartening to note that never before has such cooperation been as possible as it is in the present era. I have often thought it astonishing that our plight has arrived at a time when we not only understand the science of our planetary dysfunction, but we also have the solution within our grasp.
We are now asked to test the hypothesis inherent in our Latin binomial, Homo sapiens. Are we indeed wise humans? Has our cultural evolution allowed us to mature beyond our organic programming? In this long planetary emergency can we overcome our tribalism to extend our obligate sociality to include everyone on earth?

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