Proposing a planetary boundary for terrestrial ecosystem loss
By Dr. Glen Barry, December 16, 2012
Paper presented at the Kerala Law Academy International Law Conference on Conservation of Forests, Wildlife and Ecology, December 15-17, 2012
Full Paper: http://bit.ly/EIKeralaPaper
Theme - The Legal Regime and Measures for Conservation of Bio Diversity and Protection of Ecological Balance of Western Ghats
“Earth provides enough to satisfy every man's need, but not every man's greed.” – Mahatma Gandhi
"How wonderful it is that nobody need wait a single moment before starting to improve the world." – Anne Frank
*Version 1.0, not yet peer reviewed, or final edits for publication in conference proceedings
Review Paper Abstract
Planetary boundary science continues the study of requirements to avoid ecosystem collapse and to achieve global ecological sustainability, by defining key thresholds in the Earth System's ecological conditions that threaten human well-being. Terrestrial ecosystems do not enter into the nine originally defined boundaries ranging from climate change to water availability, except peripherally through other boundaries such as land use and biodiversity. A rigorous research agenda is necessary to determine what quantity and quality of terrestrial ecosystems are required across landscapes so as to sustain the biosphere. This includes a spatially explicit way of indicating what extent of a landscape, bioregion, continent and global Earth System must remain in the form of connected and intact core ecological areas and semi-natural agroecological buffers, in order to sustain local ecosystem services as well as the biosphere commons. Connectivity of large ecosystem patches which remain the matrix for the landscape is a preeminent consideration. When ~60% of a natural ecosystem habitat remains, after just under 40% of the ecosystem has been destroyed, the landscape is said to percolate, and we see critical collapse of the "percolating cluster" – the dominant large habitat patch constituting the matrix of the landscape – into smaller, more distant habitat, in a sea of human development. This critical deterioration of habitat connectivity continues so that at or near 50% loss of a landscape or bioregon's natural vegetation, the natural habitat percolates from people within ecosystems, to natural islands surrounded by human works. This transition is likely to be similar at a continental and global scale.
A new planetary boundary threshold is proposed: that 60% of terrestrial ecosystems must be maintained across scales – with the boundary set at 66% as a precaution – as a safe space not only for humanity but for all life and to maintain the long-term viability of the biosphere. It is thought that loss and diminishment of terrestrial ecosystems aggregates from the local and regional scale, yet disrupts planetary process with this global scale threshold. It is hypothesized that ensuring natural ecosystems and their biogeochemical flows remain the context for human endeavors is a requirement to sustain the biosphere for the long term, and that fundamentally this requires large core ecological areas, and the critical connectivity of ecosystem processes and patterns, as the global and fractal landscape matrix. It is further proposed on the basis of ecology's percolation theory that two-thirds of the 66% of terrestrial ecosystems must be protected as ecological core areas (in total 44% of the global land mass as intact ecological cores, 22% as agroecological, agroforestry and managed forest buffers, and transition zones), to ensure the ecological integrity of the semi-natural agroecological landscapes, to maintain critical ecosystem connectivity across scales, and encompass semi-natural landscapes and bioregions within a matrix of intact nature to ensure that their own ecological patterns and processes are sustainable. Up to 50% of Earth's land surface has already been transformed from mostly wild to mostly anthropocentric, so the biosphere is likely to have already lost its global percolating cluster. If indeed bioregional and global scaled landscapes are similar to landscape and bioregional pattern, terrestrial ecosystem connectivity is already critically lacking, and the global ecosystem now exists as patches of nature within a sea of humanity. It is urgent to protect most of what remains and to begin reconstructing connected ecological landscape matrixes of intact ecosystems across scales, so that globally the biosphere can percolate back to connected nature as the provider of top-down context to human and all life.
To have meaning in guiding global ecological sustainability policy, these continental and global observations – and proposed 66% presence / 44% protected – planetary boundary for terrestrial ecosystem loss must be grounded in real-life landscape and bioregional conservation considerations. An example are efforts to achieve ecological sustainability, including maintaining continued viable populations of Asian elephants in the Western Ghats bioregion of India, particularly within Kerala state, as an umbrella species. The Asian elephant requires extensive and adequate natural habitat for its survival, and the Western monsoon depends upon forest-dependent pressure gradients – and thus the provision of both provides for water, clean air, soil, pollinators, and other ecosystem services for the region, nation, and biosphere. An initial expansive regional ecosystem mapping exercise that seeks to identify natural gradients in ecological importance has taken place in Kerala, but its largely top-down processes have faced organized socio-political resistance, it is not clear the scientifically valid mapping processes have enough understanding and support, and the legal structure is not in place to tie its requirements for local and regional sustainability to laws. As a real-world example, elephants moving across landscapes are emblematic and widely visible examples of the myriad types of flows that continue on a connected landscape, making life possible. It is suggested that as go the Western Ghats' and Kerala's Asian elephants and their habitat, so shall go the biosphere, and that it is crucial to build awareness that healthy ecosystems are essential to both local advancement and global sustainability. On the basis of taking such an ecosystem and landscape approach to the needs of Earth System sustainability, and given pernicious trends of ecosystem loss and decline, it is concluded that more attention is needed to prevent worst-case outcomes including biosphere collapse and a lifeless Earth, particularly because of abrupt climate change and ecosystem loss. A massive and global program to protect and restore natural ecosystems – funded by a carbon tax on fossil fuels – is presented as the sort of policy approach necessary at this time to avoid biosphere collapse. Humanity is now the major force shaping the biosphere, which, if current trends in ecological loss and diminishment continue, may collapse or die as a result.
Full Paper: http://bit.ly/EIKeralaPaper