New environmental boundaries set limit for ‘safe and just’ human future

Humans are taking colossal risks with the future of civilisation and everything that lives on Earth, a new global study involving experts from The Australian University (ANU) shows. 

In a world-first, a group of more than 40 researchers from the Earth Commission have identified safe and just boundaries for five critical domains that play a key role in supporting life and planetary stability. 

These ‘Earth system boundaries’ provide one of the most holistic measurements of our planet’s finite limits and will form the backbone of the next generation of sustainability targets and practices.

“The study explores what’s needed to minimise significant harm to humans as a result of changes in the Earth system,” Dr Steven Lade, study co-author and ARC Future Fellow at the ANU Fenner School of Environment and Society, said. 

“It sets boundaries at scales relevant for assessment and management of the conditions of biophysical systems, such as the biosphere and freshwater.” 

Concerningly, nearly all of the safe and just limits have already been breached. 

For example, the authors identify a temperature increase of one degree Celsius as the safe and just limit to avoid significant harm from climate change, which the Intergovernmental Panel on Climate Change states has already been breached. 

The findings underscore the urgent need for action across climate, the biosphere, freshwater, nutrient cycles and aerosol pollutants, as well as the need for just transformations. 

“Overwhelming evidence shows that a just and equitable approach to both goal setting and transformation to achieve the goals is essential to planetary stability,” Professor Joyeeta Gupta, co-chair of the Earth Commission, said. 

“We cannot have a safe planet without justice. Anyone building a resilient company, institution or nation for the long term must work towards this future.” 

While previous research has studied the ‘safe’ limits of climate and other critical processes, this is the first to incorporate ‘justice’ into scientific analysis. These ‘just’ boundaries are limits at which humans are protected from significant harm and, in some places, are more stringent than the ‘safe’ boundaries. 

“This study shows how the protection of the planet is inseparable from the success of communities, societies and economies” ANU Distinguished Professor Xuemei Bai, study co-author and Earth Commissioner leading the working group on cross-scale translation, said. 

“These boundaries need to be translated for actors across all levels, in particular cities and businesses. It will enable them to understand their fair share of resources and responsibilities, and to take measurable action to minimise their footprint on the planet that also help improving human wellbeing.” she said. 

The research was undertaken by the Earth Commission, which is hosted by Future Earth and is a part of the Global Commons Alliance. 

The paper is published in Nature.