For some time now, scientists and environmentalists have sounded the alarm that our planet is sick. But do we really know how sick it is? One way that scientists have been grappling with this puzzle is through the budding concept of “planetary boundaries.”
Will Steffen and coauthors (2016) postulate that a planetary boundary (PB) is a safe operating space for human societies to thrive as constrained by the underlying biophysical process of the Earth System. The concept of PB recognizes that the earth can only operate in a relatively stable condition such as we have today if certain boundaries are not breached. To go beyond certain limits could threaten the capacity of the earth to sustain life as we know it. In other words, keeping within planetary boundaries is to be in the “safe zone of development.”
The boundary varies with the specific biophysical process as modified by human activities. Of these processes, those that have surpassed their planetary boundaries, or those that are posing increasing and high risk, include biosphere integrity (e.g., biodiversity), biogeochemical flows (nitrogen and phosphorus loading of rivers and lakes), climate change and land system change (e.g., deforestation).
To illustrate, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services assessment report (2019), three-fourths of the planet’s land surface has already been modified by humans. Such modification has led to the loss of plants and animal species, loss of livelihoods and socioculturally significant places, degraded landscapes, and to increasing greenhouse gases in the atmosphere.
While the science is in its infancy, there are clear signs that human activities are shaping the state of the planet in ways that no one can fully predict. What can we do? More and more, we will have to act considering not just local and national impacts, but also planetary impacts.
Scientists are exploring how the concept of PB can guide decision-makers. For example, Ibrahim Algunaibet and coauthors (2019) incorporated PB into energy systems models by linking energy generation with the Earth’s ecological limits, with the United States as a test case. They pointed out that ignoring PB could lead to energy mixes that could negate sustainable development aims. For example, the proportion of fossil fuels as energy source will have an enormous effect on the rate of global warming. Another sector with significant impact on PB is that of agriculture and food systems, which are major contributors to nitrogen and phosphorus flows as well as greenhouse gas emissions (see Bruce Campbell and coworkers 2017). Practices such as chemical fertilizer application, if done improperly, could lead to water pollution and climate change.
Clearly, the way forward is fraught with complexity, uncertainty and huge risks. Issues related to equity and social justice, even democracy itself, are just some of the more contentious issues that need to be addressed before the concept of PB becomes a real force in society. For instance, will imposing the concept of PB lead to a top-down approach led by so-called experts? Operationalizing the concept of PB by intergovernmental organizations, government entities as well as the private sector is still subject to ongoing inquiry and debate.
However, the state of knowledge should not lead to paralysis. There are enough indicators pointing to a sick planet, the concept of PB being just one of them. Fortunately, there are numerous multiple-benefit solutions that reduce ecological footprints while allowing for economic progress and profits. At the local and individual levels, each of us can do our share to minimize the impacts of our actions on the planet we all share. At the same time, we must increasingly open our minds to planetary perspectives that view local action in light of global implications.
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Rodel D. Lasco is an author of several Intergovernmental Panel on Climate Change reports, including the forthcoming sixth assessment report. He is the executive director of The OML Center, a foundation devoted to discovering climate change adaptation solutions (https://www.omlopezcenter.org/)