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Trevor Hancock: We have already passed safe and just planetary boundaries

Researchers have re-worked planetary boundaries by adding justice component
A woman uses a cold bandana to cool off during this week’s heat wave in Austin, Texas. JAY JANNER, AUSTIN AMERICAN-STATESMAN VIA AP

Last week, I noted the concept of planetary boundaries has been around for over a decade. A 2009 ­publication by Johan Rockstrom and his colleagues at the ­Stockholm Resilience Centre identified a number of key Earth systems fundamental to natural processes and human wellbeing, and “thresholds which, if crossed, could generate unacceptable environmental change” were identified.

Now Rockstrom — currently at the Potsdam ­Institute for Climate Impact Research — has led another team in re-working the planetary boundaries by adding a justice component. In doing so, they are ­identifying not just a safe operating space for humanity, but a safe and just operating space, one that will minimize ­“exposure to significant harm to humans from Earth system change.” To do so, they looked at eight Earth system domains that are important for human ­wellbeing: climate; two measures of the biosphere (the area of largely intact natural ecosystems and the functional integrity of all ecosystems); two measures of water (surface flows and ground water levels); flows of two key nutrients – nitrogen and phosphorus; and ­atmospheric aerosols (air pollution).

Each of these systems, they noted, “have impacts on policy-relevant timescales; are threatened by human activities; and could affect Earth system ­stability and future development globally.” For each, they then assessed whether “adhering to the safe ESBs [Earth system boundaries] could protect people from ­significant harm,” knowing that any such harm “will lead to greater impacts when vulnerable populations are exposed.”

They assessed the ESBs using three justice ­criteria: intragenerational justice, which is about justice in today’s world “between countries, communities and individuals”; intergenerational justice, which is ­concerned with the “relationships and obligations between generations”; and interspecies justice, “which aims to protect humans, other species and ­ecosystems. The latter in particular “could be achieved by ­maintaining Earth system stability within safe ESBs.”

Their conclusions are sobering: “Seven of the eight globally quantified ESBs have been crossed and at least two local ESBs in much of the world have been crossed, putting human livelihoods for current and future ­generations at risk” — the one that was not exceeded globally was atmospheric aerosols, which is a regional rather than a global measure. (An accompanying map shows the greatest levels of exceedance are found in a band from Indonesia and Indo-China across India and the Middle East and up into central and eastern Europe.)

The climate ESB is worth further ­consideration, especially considering that climate, along with ­biosphere integrity, is considered a core planetary boundary, according to a 2015 updated article on ­planetary boundaries by the Stockholm Resilience ­Centre team. This is because “large changes in the climate or in biosphere integrity would likely, on their own, push the Earth system out of the Holocene state” — the relatively stable state experienced by humans in the past 12,000 years.

Referring to what Timothy Lenton’s team found (referred to in last week’s column on the unjust impact of climate change), Rockstrom and his colleagues pointed out that at 1.5 C warming — the optimistic ­target established in the Paris Accord — “more than 200 million people, disproportionately those already vulnerable, poor and marginalized … could be exposed to unprecedented mean annual temperatures.” In addition, they noted, “more than 500 million could be exposed to long-term sea-level rise.”

This they consider to be unjust, so they recommend the safe and just boundary for climate change be set at or below 1 C. However, they acknowledge, since we are already at 1.2 C of warming, and on track for ­further warming, “this boundary may not be achievable in the foreseeable future,” adding that “adaptations and ­compensations to reduce sensitivity to harm and ­vulnerability will be necessary.”

So where does this leave us? Rockstrom and his ­colleagues are clear: “Nothing less than a just global transformation … is required to ensure human ­well-being. Such transformations must be ­systemic across energy, food, urban and other ­sectors, ­addressing the economic, technological, political and other drivers of Earth system change, and ensure access for the poor through reductions and reallocation of resource use.”

As Thomas Homer Dixon wrote with reference just to climate change: “Our responses … must be far more radical than we’re currently envisioning. ­Incrementalism is now a waste of time and resources.”

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Dr. Trevor Hancock is a retired professor and senior scholar at the University of Victoria’s School of Public Health and Social Policy.

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