It’s all about the safe operating space

The Planetary Boundaries concept will be ten years old in September 2019. What impact has it had in academia? To answer that question, researchers at the centre analysed the paper’s citations to assess the academic research and discussion sparked by concept – a discussion that is still going strong.

"The high number of citations of the Planetary Boundaries papers reflects how much demand there is for sustainability concepts. We wanted to assess if the planetary boundaries concept meets those needs and how," says lead author Andrea Downing.

In 2009, the paper “A safe operating space for humanity” was published in Nature, followed by a longer article in Society and Ecology. The papers proposed a new Earth system framework for risk management under uncertainty called the Planetary Boundaries Framework. As of 6 May 2019, these two papers have been cited 3885 times according to the Web of Science.

A signpost to a different route

A main finding from the research is that the planetary boundaries framing has focused discussion on maximum allowable impacts on the Earth system. This can overshadow an important role of the concept as a “signpost to a fundamentally different” route to sustainable development, one which acknowledges a Holocene-like Earth system as a prerequisite for future development.

“The emphasis needs to be on the “safe operating space”, not the limits,” suggests Downing.

Downing and colleagues separated the research papers into three main groups. The first group, “commentaries”, was the biggest collection of papers. Here, researchers have, for example, used the planetary boundaries concept to underpin their own arguments relating to human impact on the Earth system, or described the challenges that different contexts bring to applying planetary boundaries research. The second basket contained papers that advanced the planetary boundaries concept as an Earth system framework. The final group explored how to use the concept, for example to apply it at national or regional scales or explore links to social dimensions, such as behaviours, impacts, needs or aspirations.

Applying and criticizing the concept

The researchers found that three boundaries attracted the most critique: biodiversity, land use and water. One paper, for example, by leading biodiversity expert Georgina Mace from Imperial College, London, challenged the biodiversity metrics used and suggested alternatives. These were later incorporated into the first major update of the boundaries concept in 2015. In 2013, Dieter Gerten from the Potsdam Institute for Climate Impact Research in Berlin, and colleagues, queried the water boundary and suggested that human freshwater usage may be lower than previous estimates.

Two boundaries have remained unquantified: chemical pollution (now “novel entities” such as herbicides, pesticides, plastics, GMOs) and aerosol loading (small particles in the atmosphere). To date, only the chemical pollution boundary has spurred further research. The core planetary boundaries team, though, plans a series of workshops on both boundaries in 2019/2020.

Over 70 papers focused on applying the concept, by including social dimensions and re-scaling the planetary level of the processes to the scales at which sustainable development can be enacted. Downing and team categorise these papers according to four terms: needs, aspirations, behaviours and impacts.

Most research focuses on impacts of human activities on planetary boundary processes, for example impacts of agriculture on land-use or water systems. Other research questions centre on matching boundary values to human needs – for instance water or food requirements – or seeks to derive what social transformations (behaviours) can lead away from boundaries. A small but highly relevant fraction of the literature matches social goals to the boundaries (aspirations, e.g. Raworth).

Downing adds, “To shift from a boundary focus to a safe operating space focus we need to bring out the human dimensions and interrogate what sustainable futures look like, for whom, where and who can or should contribute to building them.”

Design tools to implement the concept

The Planetary Boundaries concept has clearly provided a much-needed platform for research on issues of sustainable development. It has triggered widespread and interdisciplinary research and increased awareness of global sustainability challenges. There is nonetheless still more talk than action in terms of developing the concept for use, which clearly shows that the task at hand is not trivial.

Downing and her team identify that a crucial area for future research lies in designing tools with which to implement the concept, addressing human dimensions and understanding the interdependencies between social-ecological processes that shape safe-operating spaces.

Indeed, commonly used footprints approaches fail to account for the interdependences of Earth system processes that is central to the concept, and leaves behind the resilience framing that is essential to navigating safe operating spaces for humanity.