Contribution to GTI Roundtable "Bounding the Planetary Future"

Noel Castree

Johan Rockström’s essay develops a line of is-ought thinking he has expressed in high-profile co-authored peer review papers.1 He uses three intersecting ideas promoted by sizeable teams of environmental scientists to argue that a Great Transition is now more necessary than ever before. They are the ideas of planetary boundaries, the Anthropocene, and global tipping points. I endorse his ultimate message about the need for root-and-branch change to the prevailing socio-technical order. However, his essay arguably alerts us to problems that may lie ahead for him and his many collaborators in the networks and programs of global change science. For all his insistence on the need for societal change—an "ought" issuing from the evidence presented in recent papers in Science and The Anthropocene Review—his own argumentative practices continue an old practice of trying to scientize politics.2 Looking ahead, these practices may not be the best basis on which global change science can shape public policy at the global and national levels.

The planetary boundaries concept abstracts information about local and regional environmental change and seeks to identify thresholds that stand to have global significance if transgressed. The related concept of a "safe operating space" is clearly a normative one, and is implied to be a rational inference from present facts about escalating human impacts on Earth. Rockström and his collaborators (e.g., Jeffrey Sachs) have already enjoyed some considerable success in getting the concepts taken seriously by senior members of the United Nations. At the same time, his central involvement in Future Earth—the umbrella for a new phase of global change science—means that these concepts will at some level shape future research into how humans affect, and ought to respond to, a post-Holocene world. This is all to the good, despite the justified reservations expressed by some.3

However, it seems to me that Rockström and his collaborators need to think again about the roles they are playing as "scientists" and their relationships to political institutions and wider publics. Rockström’s essay moves uneasily been old fashioned is-ought reasoning and outright advocacy of a Great Transition on non-scientific grounds. There is absolutely nothing wrong with either practice, in the right situations. But mixing the two up when writing or speaking to others as a "scientific researcher" can produce a whole brew of problems identified by Roger Pielke in his much cited book The Honest Broker: Making Sense of Science in Policy & Politics.4

Pielke coins the term "stealth issue advocacy" to refer to situations when scientists use evidence (or robust predictions) to argue that certain governmental decisions are virtually mandated by science. This is relatively uncontentious in what Pielke calls "Hurricane politics" situations where the level of scientific uncertainty about risks or harms is low and the level of "values consensus" about appropriate societal responses is high. However, it amounts to an illicit scientization of political reasoning in what he calls "Abortion politics" situations. These are situations where scientific uncertainty about the phenomena under investigation is high and values consensus about appropriate societal responses to possible risk or harms is low. In these situations, Pielke argues, scientists need to act as "honest brokers of policy alternatives." Rather than aligning the “is” of their research findings with one or other “ought” about how society should respond, scientists should seek to clarify the implications of their discoveries for a range of value-based options about how society might respond.

In the present case, Rockström’s argument for a more equitable world order does not flow logically from his collaborative research into planetary boundaries. Rather, it is a value-based critique of the socio-economic and geographical inequality rife in the early twenty-first century. I wholeheartedly agree that greater equality is desirable. However, there are surely risks when he and other senior geoscientists try to pass off value-based arguments as a “necessary” implication of their ostensibly “value free” research.

This much was obvious years ago when climate change skeptics in the USA and elsewhere politicized the science because they detected an unwelcome coupling between science and certain value-based policy proposals (notably the reduction of fossil fuel consumption). Happily, the years of such skepticism seem to be behind us. However, I suspect that the more they make strong is-ought claims, the more Rockström and his collaborators may find that their words fall on deaf ears. The levels of scientific uncertainty about planetary thresholds and what constitutes a “safe operating space” are high. There is inevitably also an absence of values consensus on whether something so profound as a Great Transition is needed globally. Global leaders have struggled to action even something as tame as an effective regime to reduce greenhouse gas emissions levels. Given this, there is a risk that prominent members of the global change science world may be perceived by outsiders as over-reaching.

Today is not like the late 1970s when the conditions were propitious for a few leading scientists to shape Cold War nuclear weapons policy by advancing the idea of a “nuclear winter.” Pielke’s vision of honest brokering suggests the need to avoid issue advocacy so that scientific researchers can help decision makers avoid the political stand-off that routinely accompany contentious public issues (like legalized drug use or the right of women to abort a fetus). Put differently, Pielke suggests that issue advocacy should be transparent (not stealthy) and that it should ultimately not trump scientists’ collectively playing the honest broker role.

This said, we are arguably on the threshold of a new era of “science-based policy” worldwide. Rockström and his coauthor's determination to make broad normative claims anticipates the much needed involvement of a wider range of social scientists and humanists in global change science. These researchers can help decision makers achieve a far richer understanding of actual and possible “human dimensions” than is provided by currently prominent approaches like environmental economics.5 Many explore normative issues and various forms of value-based action in ways that are evidenced-based, principled, and transparent. The greater involvement of social scientists and humanists could change the current “social contract” between global change researchers and various non-academic stakeholders. It could ultimately challenge the fact-value distinction that guides Pielke’s otherwise useful arguments. It could ensure that Rockström and colleagues can talk about values and goals without using stealth and scientization as tactics. In sum, we need a “great transition” in the present academic division of labor and the way decision-makers define the “proper” roles played by natural scientists, social scientists, and those in the humanities. The GT Network can help foster that, and so, too, can Rockström and his various collaborators across the disciplines. Ideas like a safe operating space merely establish the preconditions for what needs to be an open and informed values-based debate about the sort of Earth we want future generations to inherit. Sadly, we appear to lack sufficient grassroots pressure for such a debate to occur worldwide, not to mention a news media that still treats ‘the environment’ as one ‘issue’ among many others. Given this, it’s understandable that concerned scientists will want to play politics in their ostensibly non-political observation about global environmental change. But as I have argued, I doubt this tactic will change the hearts and minds of political leaders and economic elites.

1. Will Steffen et al., “Planetary Boundaries: Guiding Human Development on a Changing Planet,” Science 347, no. 6223 (January 2015): 736-46,
2. Ibid.; Will Steffen et al., “The Trajectory of the Anthropocene: The Great Acceleration,” The Anthropocene Review (January 2015): 1-18,<.
3. Fred Saunders, “Planetary Boundaries: At the Threshold… Again: Sustainable Development Ideas and Politics,” Environment, Development, and Sustainability (September 2014),
4. Roger Pielke, The Honest Broker: Making Sense of Science in Policy and Politics (New York: Cambridge University Press, 2007).
5. Heide Hackmann et al., “The Social Heart of Global Environmental Change,” Nature Climate Change 4 (August 2014): 653-555,

Noel Castree
Noel Castree is a Professor of Geography at the University of Wollongong, Australia, and the University of Manchester, England. He is the author and editor of several books on human-environment relations, including Nature (2005) and Making Sense of Nature (2014).

Cite as, Noel Castree, contribution to GTI Roundtable "Bounding the Planetary Future," Great Transition Initiative (April 2015),

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