The nine boundaries are important physical markers of ecosystem health. When crosses, the ecosystem because unstable likely in nonlinear ways, meaning that efforts to restore ecosystem stability once those boundaries are crosses become much more difficult. Because the form of ecosystem instability that occurs when the boundaries are crossed are nonlinear, this may lead to abrupt, irreversible ecological changes.
The general importance of these boundaries is two-fold. First, in identifying conditions that are dangerous in terms of ecosystem stability and survival. And second, as indicators of the effect of humans, and in particular human production and consumption patterns on ecosystem stability since the industrial revolution. The rise in individual components of the planetary boundaries are measures of ecologically adverse conditions. As related research indicates, these boundaries are being changed by human behavior, and thus controlling human behavior is essential to survival of the planet.
Although nine planetary boundaries have been proposed, there are currently only adequate scientific measures of seven of those boundaries. The nine boundaries areas are follows:
1. Biogeochemical. This boundary is made up of two individual boundaries for nitrogen and phosphorous pollution. The nitrogen boundary has already been crossed; the phosphorous boundary has not been crossed.
2. Climate change. Measured by mean atmospheric carbon dioxide concentration or as radiative forcing, the climate change boundary has been crossed.
3. Ocean acidification. The mean of global ocean acidification measured by the aragonite concentration in surface seawater. This boundary has not been crossed.
4. Biodiversity loss. Measures the extinction rate for species. The extinction rate for species has increased significantly since the industrial revolution and has exceeded the specified boundary.
5. Land use. The land use measure is an indicator of the volume of land converted to agricultural production as a percentage of land space. This boundary has not been crossed.
6. Freshwater use. This is a measure of global freshwater use, and thus describes the global boundary and not geographic variations in that boundary. The freshwater use boundary has not been crossed.
7. Ozone depletion. The ozone depletion boundary is a good example of how international cooperation on setting boundary limits has prevented a boundary from being crosses. This is a measure of stratospheric ozone concentration.
8. Atmospheric aerosols. Atmospheric aerosol chemicals play a role in other processes such as climate change. While scientists agree that these chemical are important, there is currently no scientific agreement as to the concentrations of these chemical that forms a boundary.
9. Chemical pollution. Chemical pollutants are not globally ubiquitous. There is no agreement, however, as to the concentration of such chemicals for the purpose of establishing a planetary boundary.
For green criminologists, these boundaries are important in two ways. First, as empirical measures of the forms of harm humans produce and the kinds of adverse impacts humans have on the ecosystem. Second, these boundaries also serve as measures of different forms of harm against the ecosystem that may be considered to form categories of green crime or as a mechanism for grouping green crimes. To date, green criminologists have not given much attention to the issue of planetary boundaries (for an exception see, Lynch et al., 2013; Stretesky, Long and Lynch, 2014).
For additional details see the website of the Stockholm Resilience Center: Link.
Lynch, Michael J., Michael A. Long, Kimberly L. Barrett and Paul B. Stretesky. (2013). Is it a Crime to Produce Ecological Disorganization? Why Green Criminology and Political Economy Matter in the Analysis of Global Ecological Harms. British Journal of Criminology 55, 3; 997-1016.
Stretesky, Paul B., Michael A. Long and Michael J. Lynch. (2014). “The Treadmill of Production, Planetary Boundaries and Green Criminology.” In T. Sapiens, Rob White and M. Kluin’s (eds), Environmental Crime and Its Victims. Devon, UK: Ashgate.