Johan Rockstrom with SP Wani during a field visit at ICRISAT-Patancheru. (photo credit)
Ecologist Johan Rockström begins by reminding us modern humans have just experienced “10,000 years of grace,” an interglacial period capable of supporting human development. He tells us we’re currently putting the planet into a “quadruple squeeze” through pressures of human growth and inequality (80% of climate impact from 20% of people), climate change (whether we end up at 350/450/550ppm of CO2), ecosystem loss (loss of 60% of species), and the problem of surprise – rapid tipping points.
Rockström tells us that may be at a point where humans are the main pressure on the planet. It’s not just CO2 that maps a hockey stick – methane, nitrous oxide, loss of species, ozone depletion all have a distinctive, rapidly rising curve. There was a massive acceleration on those curves in the 1950s. And it’s possible that we currently face the most challenging decade in human history, a decade where we have to “bend the curves”.
Natural systems have stable states and thresholds. Think of a ball rolling on a curved surface. One measure of resilience is the depth of the cup. But when the ball reaches a local maximum, it can quickly tip into another state (as he says this, he steps off the stage, lands on his feet after a few foot fall, and continues his talk without breaking stride.)
Systems can collapse very quickly. Coral reef systems can turn from thriving ecosystems to systems that have lost diversity very quickly. We may have just seen a possible threshold in the arctic – we rapidly lost 30% of reflective ice cover. This is the largest red flag warning for humanity, he tells us.
Nine factors, and their interactions, serve as “planetary boundaries”: climate change, ozone depletion, aerosol loading, ocean acidification, freshwater use, chemical pollution, land system change, rate of biodiversity loss, bio-geochemical loading, and global nitrogen and phosphorous cycles. Rockström tells us that we’ve crossed the boundary on three of these factors – nitrogen flow, biodiversity loss, and climate change.
Is sustainable development utopia? No – we can fix this – there’s evidence we can. In Latin America, collapsed farmland was recovered through zero-till, mulch-based farming. The Great Barrier Reed, which was beginning to collapse, has now been revived due to a new governance strategy, and there’s a new focus on putting redundancies and diversity in the natural system. In Sweden, swamplands that were considered worthless flood zones are now being reincorporated into urban planning.
We face the largest transformative development since industrialization. But he argues that we can manage it if we build resilient systems.
This post originally appeared on Ethan's excellent blog My Heart's in Accra.