An international team of researchers has identified nine planetary boundaries that must be maintained in order to sustain life on earth as we know it. Of those nine, we have already crossed the thresholds of four in such as way as to “fundamentally change the functions of nature.” By “degrading land and freshwater systems, emitting greenhouse gases and releasing vast amounts of agricultural chemicals into the environment” we are, the researchers say “eating away at our own life support systems.”
The team of 18 includes researchers from Scripps Institution of Oceanography at UC San Diego, the Australian National University and the Stockholm Resilience Centre. Together they spent five years identifying nine planetary boundaries, whose “processes and systems regulate the stability and resilience of the earth system,” as well as the current standing of those boundaries.
The nine boundaries are:
- Climate change
- Change in biosphere integrity (biodiversity loss and species extinction)
- Stratospheric ozone depletion
- Ocean acidification
- Biogeochemical flows (phosphorus and nitrogen cycles)
- Land-system change (for example deforestation)
- Freshwater use
- Atmospheric aerosol loading (microscopic particles in the atmosphere that affect climate and living organisms)
- Introduction of novel entities (e.g. organic pollutants, radioactive materials, nanomaterials, and micro-plastics).
Of these, climate change and biosphere integrity are “core boundaries,” and any significant change in these would “drive the earth system into a new state.” Yet, we have already crossed into a “zone of uncertainty” in not just climate change and biosphere integrity, but also biogeochemical flows and land-system change.
In the words of one of the team, Veerabhadran Ramanathan, the findings are “sobering.” Speaking to the Guardian, the report’s lead author Will Steffen explained that these systems have shot up since 1950, and show no signs of slowing down. “When economic systems went into overdrive, there was a massive increase in resource use and pollution,” Steffen said. “It used to be confined to local and regional areas but we’re now seeing this occurring on a global scale. These changes are down to human activity, not natural variability.”
He continued: “It’s clear the economic system is driving us towards an unsustainable future and people of my daughter’s generation will find it increasingly hard to survive. History has shown that civilizations have risen, stuck to their core values and then collapsed because they didn’t change. That’s where we are today.”
The findings were published January 16 in the journal Science, and will be presented as a series of seminars at the World Economic Forum in Davos on January 21-24.
Via The Guardian
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