Portland State University PDXScholar Institute for Sustainable Solutions Publications and Presentations Institute for Sustainable Solutions 5-1-2011 How Defining Planetary Boundaries Can Transform Our Approach to Growth W. L. Steffen Johan Rockström Robert Costanza Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/iss_pub Part of the Sustainability Commons Let us know how access to this document benefits ou.y Citation Details Steffen, W., Rockström, J., & Costanza, R. (2011). How Defining Planetary Boundaries Can Transform Our Approach to Growth. Solutions: For A Sustainable & Desirable Future, 2(3), 59-65. This Article is brought to you for free and open access. It has been accepted for inclusion in Institute for Sustainable Solutions Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Feature HowDefiningPlanetary BoundariesCanTransform OurApproachtoGrowth byWillSteffen,JohanRockström,andRobertCostanza Rockström et al. Nature (2009) and Ida Kubiszewski/Solutions The globe represents the proposed safe operating space for the nine planetary systems. The wedges represent an estimate of the current position for each variable. The boundaries in three systems (rate of biodiversity loss, climate change, and human interference with the nitrogen cycle) have already been exceeded. InBrief Our planet’s ability to provide an accommodating environment for humanity is being challenged by our own activi- ties. The environment—our life-support system—is changing rapidly from the stable Holocene state of the last 12,000 years, during which we developed agriculture, villages, cities, and contemporary civilizations, to an unknown future state of significantly different conditions. One way to address this challenge is to determine “safe boundaries” based on fundamental characteristics of our planet and to operate within them. By “boundary,” we mean a specific point related to a global-scale environmental process beyond which humanity should not go. Identifying our planet’s intrinsic, non- negotiable limits is not easy, but here we specify nine areas that are most in need of well-defined planetary boundaries, and we explain the steps needed to begin defining and living within them. www.thesolutionsjournal.org | May-June 2011 | Solutions | 59 Author Note: This article is based on move to someplace else. As human that certain preconditions must be set the papers “A safe operating space for population has grown, these short- that acknowledge and respect those humanity,”1 published in Nature, and term solutions are no longer viable. boundaries. “Planetary boundaries: Exploring the Furthermore, the impacts of our pres- This new situation is captured in safe operating space for humanity,”2 ence were not usually felt beyond our the concept of the Anthropocene, a published in Ecology and Society. See immediate surroundings. This is also newly defined geological era beginning these papers for a complete description of no longer the case. The global envi- around the 1800s, with the Industrial the planetary boundaries. Here, we pres- ronment has provided an especially Revolution. The term was introduced ent the underlying concepts and suggest and popularized by Nobel Laureate ways to limit continued growth of the Paul Crutzen,5 who felt the recent influ- material economy on a finite planet. Key Concepts ence of human activity on the Earth was significant enough as to constitute The Challenge the naming of a new epoch. The past • In the last 200 years, humanity has Over the past half century, we transitioned into a new geological 12,000 years or so is a period defined by have become adept at dealing with era—termed the Anthropocene— geologists as the Holocene, an epoch environmental problems on a local which is defined by an accelerating in which global average temperature departure from the stable environ- and global scale. The worst excesses mental conditions of the past 12,000 has been remarkably stable and during of the Industrial Revolution have, in years into a new, unknown state of which time agriculture developed, fol- many cases, been ameliorated. Rivers, Earth. lowed by the appearance of ever larger such as the Thames in London, have settlements and the development of been cleaned up and the air quality • In order to maintain a global environ- complex civilizations in Africa, Asia, ment that is conducive for human in major cities, such as Los Angeles, development and well-being, we South and Central America, and the is better. Synthetic pesticides once must define and respect planetary Mediterranean region. sprayed on our crops, such as DDT, boundaries that delineate a “safe Since the Industrial Revolution, operating space” for humanity. We have been banned in most developed must return to the long-term stable the human enterprise has expanded so countries, and lead has been removed global environment that nurtured rapidly that we are now overwhelm- from petroleum-based fuels. These human development. ing the capacity of the Earth system to impressive successes have been absorb our wastes and to sustainably celebrated, perhaps most notably in • The nine areas that are most in need provide the services we require. In of planetary boundaries are climate Bjorn Lomborg’s book The Skeptical change, biodiversity loss, excess the period since the Second World Environmentalist.3 nitrogen and phosphorus production, War, the acceleration of development However, to say we have done stratospheric ozone depletion, ocean has become particularly dramatic. acidification, global consumption of enough globally would be false on two freshwater, change in land use for Humanity is fundamentally chang- counts. First, while these problems have agriculture, air pollution, and chemi- ing the Earth’s physical climate,6 been addressed in many European and cal pollution. overwhelming its capacity to provide North American nations, over three- ecosystem services, homogenizing its • We estimate that humanity has 7 quarters of the world’s people do not live already transgressed three of biological diversity, and substantially in developed countries. For them, many these boundaries: climate change, modifying the global cycles of key of the local and regional environmental biodiversity loss, and phosphorus elements like nitrogen, carbon, and problems still exist and, in many cases, production. phosphorus.8 We are indeed passing are worsening. Second, the environ- through the exit door of the Holocene • Several steps can be taken to estab- ment—our life-support system—is lish and enforce these boundaries, and into the unknown world of the under increasing threat from a wide and they are suggested here. Anthropocene. range of human pressures, many of So what is the solution to this them emanating from consumption in dilemma? Humanity needs to change the wealthy countries. The deterioration accommodating environment over course, but in what direction and of the global environment puts even the past 12,000 years for humanity what principles should guide the more pressure on the poorest countries to develop and thrive.4 But the world journey? The problem has been to limit growth, even as they struggle to population is no longer small, spread recognized for several decades, and bring their populations out of poverty. out, and technologically limited. many attempts have been undertaken This is an entirely new situation for Does our planet have boundaries to define or inform solutions—limits humanity. In the past when we fouled regarding the amount of growth it to growth,9 safe minimum stan- our local environment, we could can absorb? We believe it does and dards,10 the precautionary approach,11 60 | Solutions | May-June 2011 | www.thesolutionsjournal.org Conceptual Diagram of Boundary, reshold, and Zone of Uncertainty Planetary Planetary boundary boundary Dangerous T hreshold level (e.g., Mt yr- ) (e.g., Mt yr- Safe Zone of operating Zone of (e.g., extent of land ice) uncertainty space uncertainty Response variable carbon sequestration Terrestrial Control variable (e.g., ppm CO2 ) Land-use change (e.g., % terrestrial ecosystems under cropland) 12 and tolerable windows, for example. Table 1: Categories of Boundaries These provide an excellent knowl- SLOW PROCESSES WITHOUT BOUNDARY CHARACTER PROCESSES WITH GLOBAL edge base from which to work toward KNOWN GLOBAL SCALE SCALE THRESHOLDS a more sustainable future. SCALE OF PROCESS THRESHOLDS The Concept of Planetary SYSTEMIC PROCESSES Boundaries AT PLANETARY SCALE How do we begin to identify what aspects of our planet need boundaries and what those boundaries are? The 1,2 concept of planetary boundaries, AGGREGATED PROCESSES while building on earlier efforts, takes FROM LOCAL/REGIONAL SCALE a rather different approach. It does not focus so directly on the human enterprise, as do most of these earlier approaches, but rather emphasizes the Earth as a complex system. Here we identify nine areas that are most in need of set planetary boundaries: cli- mate change; biodiversity loss; excess nitrogen and phosphorus production, Rockström et al. Ecology & Society (2009) and Richard Morin/Solutions Our initial analysis yielded nine planetary boundaries for Earth-system processes, such as for climate which pollutes our soils and waters; change, which undoubtedly features threshold/abrupt change behavior, and for others, such as Table 2: Planetary Boundaries stratospheric ozone depletion; ocean