Offline: Progress towards planetary health

Abstract

2014 was the world's hottest year since records began in 1880—0·69°C higher than the 20th-century average, and 0·04°C higher than previous peaks. NASA's Gavin Schmidt was reported last week as saying that these latest findings do “not bode well for a civilisation that is continuing to add greenhouse gases to the atmosphere”. The news came just as Johan Rockström's team at the Stockholm Resilience Centre updated their now famous idea of “planetary boundaries”. In 2009, Rockström proposed the notion of a safe operating space for humanity. A zone of sustainable life was surrounded by nine boundaries—climate change, ocean acidification, stratospheric ozone, nitrogen and phosphorous cycles (now called biogeochemical flows), global freshwater use, land-system change, biodiversity loss, atmospheric aerosol loading, and chemical pollution. As these boundaries were crossed, Rockström argued, the sustainability of our planet would become eroded, reducing the safe operating space we inhabit. The planetary boundary concept has become a powerful lever in debates about the meaning and measurement of sustainable development. In 2013, Rockström, together with Jeff Sachs and others, wrote an influential submission for the High-Level Panel on the Post-2015 Development Agenda. That paper concluded that, “The science of planetary boundaries makes clear that we are on an unsustainable trajectory…Planetary boundaries define a planetary playing field that guide humanity on how to avoid environmental changes on a global scale.” The latest iteration of the planetary boundary approach, published in Science, includes important modifications. First, two core boundaries are identified—climate change and biosphere integrity. Adverse movements towards either boundary would likely have the necessary force to take us out of the Earth's safe operating space. Second, boundaries are given regional context. The integrity of the biosphere, biogeochemical flows, land-system change, freshwater use, and atmospheric aerosol loading all have considerable sub-global heterogeneity. Third, progress towards protecting our safe operating space is described, incorporating regional as well as global metrics. Finally, the concept of planetary boundaries is refined. For example, a boundary is not a tipping point. Instead, the gap between the boundary and the true threshold for catastrophic change not only indicates uncertainty as to where that threshold actually lies, but also provides an opportunity for early warning and action to reduce the risk of irreversible transition. Revision of the planetary boundary approach will surely continue. Most importantly, they are not yet integrated into the practical politics of sustainable development, the SDGs, or post-2015 planning. They should be. But come back to Gavin Schmidt's word—civilisation. The history of civilisations (our societies and our cultures) tells us that what often seems secure in our lives can collapse and disappear surprisingly easily. There are many well-documented examples of civilisations that have been born, grow, thrive, and then die. The time course is long—over many hundreds of years. There is an abundance of evidence chronicling the precarity of human civilisations. It is not unreasonable to suggest that it is at best complacent and at worst dangerous to think that our societies and cultures are somehow different (better and smarter) today compared with the past—that we are now immune from the forces that challenged and overcame our ancestors. History and science, to the contrary, suggest that we should take our intrinsic fragility very seriously. The planetary boundaries approach is powerful. But it repeats the mistake of saying that it is something outside of us that should be the object of our concern—carbon dioxide, acidified oceans, and so on. Not so. The object of our concern should be us. The seeds of our vulnerability lie within ourselves, not the disturbed natural systems around us. Do we have the right governance, institutions, and decision-making processes to address the predicaments we face? There is reasonable evidence to suggest that we might not. If we accept that our civilisations are fragile and if we agree that the principal threats to our species are deficiencies in human political, economic, social, and knowledge systems, surely the conclusion is that we must redefine health. Health is not only the health of individuals and populations. It is also the health of our civilisations too—what we might come to call planetary health.