STOCKHOLM – The future of humanity will depend on mastering a balancing act. The challenge will be to provide for the needs of more than ten billion people while safeguarding our planetary life-support systems. Recent scientific insights have made us better equipped than ever to strike that balance. Doing so will be our generation’s great task.
Ending poverty has become a realistic goal for the first time in human history. We have the ability to ensure that every person on the planet has the food, water, shelter, education, health care, and energy needed to lead a life of dignity and opportunity. But we will be able to do so only if we simultaneously protect the earth’s critical systems: its climate, ozone layer, soils, biodiversity, fresh water, oceans, forests, and air. And those systems are under unprecedented pressure.
For the last 10,000 years, the earth’s climate has been remarkably stable. Global temperatures rose and fell by no more than one degree Celsius (compared with swings of more than eight degrees Celsius during the last ice age), and resilient ecosystems met humanity’s needs. This period – known as the Holocene – provided the stability that enabled human civilization to rise and thrive. It is the only state of the planet of which we know that can sustain prosperous lives for ten billion people.
But humans have now become the single largest driver of ecosystem change on earth, marking the start of a new geological age that some call the Anthropocene. Scientists argue over the exact starting point of this epoch, but it can be dated to somewhere around 1945, when modern industry and agriculture began to expand briskly. In the future, geologists will see telltale markers like radioactive carbon – debris from nuclear blasts – and plastic waste scattered across the planet’s surface and embedded in rock.
More recently, human activity has undergone what is being called the Great Acceleration: the rapid intensification of resource consumption and ecological degradation. We risk disrupting the earth’s critical systems, and with them modern civilization itself.
The planet’s response to our pressures is likely to be unpredictable. Indeed, the surprises have already begun. As we overdraw on our planet’s accounts, it is starting to levy penalties on the global economy, in the form of extreme weather events, accelerated melting of ice sheets, rapid biodiversity loss, and the vast bleaching of coral reefs.
We face an urgent need to define a safety zone that prevents us from pushing our planet out of the unusually benevolent Holocene state. The Planetary Boundaries framework, which a group of scientists, including one of us (Johan), first published in 2009, does just that. It draws on the best science to identify the key planetary processes regulating the earth’s ability to sustain Holocene-like conditions. For each of those processes, it proposes a boundary – a quantitative ceiling – beyond which we risk inducing abrupt changes that could push our planet into a state that is more hostile to humanity.
These nine boundaries include climate change, ozone depletion, ocean acidification, interference in the global nitrogen and phosphorus cycles, land-use change, global freshwater use, biosphere integrity, air pollution, and novel entities (such as organic pollutants, radioactive materials, nanomaterials, and micro-plastics). Worryingly, our most recent update in January, which confirms the nine boundaries and improves their quantifications further, indicates that humanity has already transgressed four: climate change, nitrogen and phosphorus use, biodiversity loss, and land-use change.
Our challenge is to bring the earth’s systems back within the safety zone, while simultaneously ensuring that every person has the resources he or she needs to lead a happy and fulfilling life. Between these planetary and social boundaries lies humanity’s safe and just operating space: the limits we must respect if we are to create a world that is ecologically resilient and free of poverty.
Meeting these goals will require a far more equitable distribution of the planet’s resources and far greater efficiency in how we use them. If we are to ensure that our planet remains one on which all of humanity can thrive, we will have to pursue a new paradigm of prosperity.