Site-specific modulators control human responses to their local environment

Analysis of human-induced land-use changes, resulting in land cover patterns and understanding of its drivers, is hardly a new field of research, but with Homo sapiens continuously being the most dominating species of the Biosphere, the significance of the theme has not decreased. Humans have transformed more than half of the terrestrial land surface, in large part, for extraction and production of resources, with the claim now being made that we have entered into a new geological epoch, the “Anthropocene”.

In our recently published paper in Geo (Site-specific modulators control how geophysical and socio-technical drivers shape land use and land cover), we review how both geophysical and socio-technical drivers can shape land use, and how the strength of these drivers may vary geographically according to site-specific modulators. In particular, we present the site-specific modulators as a new asset to describe how drivers affect land cover patterns by considering the importance of geographic variability in the effect of these potential drivers through a conceptual interdisciplinary framework (Figure 1). The framework provides an outline for analyzing and understanding land cover patterns and their dynamics, and consists of three parts:

1) Geophysical and socio-technological drivers that shape land use

2) Site-specific modulators of the effect of the drivers on land use

3) The net effect of 1 and 2 on direct land use and as a result – land cover patterns.

Mette 1

Figure 1. Conceptual framework of how geophysical and socio‐technical drivers (part 1) shape land use via site‐specific modulators (part 2).

In this blog post, we draw attention to two of the examples presented in the paper (Figure 2).

Mette 2

The conceptual framework in Figure 1 demonstrated with examples from the literature.

From a global perspective, human population densities have been shown to be an important determinant of how well topography can explain forest occurrence (Sandel and Svenning, 2013) (Figure 2a). In this cross-scale global study, forest was well explained by topography in areas with high human populations and poorly explained in areas with low populations. This suggests that at the global scale, human land use is constrained by topographic accessibility even – and in fact, especially – where human population pressure is high. Hence, human population, as a site-specific modulator, drives the topographic-forest relationship. Another, more regional study describes how sandy soils and cattle densities drive maize distributions depending on temporal changing temperature (Figure 3) (Odgaard et al., 2011). Maize distributions have increased over a decade for the Danish lowland region. In the beginning of the study period when temperatures were relatively cool, maize distribution was strongly linked to sandy soils. Sandy soils have a higher heating rate compared to loamy soils, thereby increasing the probability for maize to germinate. Towards the end of the study period, characterized by relatively warm temperatures, maize distributions gradually decoupled from the sandy soils, whereas cattle densities increased in their importance. In this example, temperature can be described as the time-specific modulator (Figure 2b).

Mette 3

Influence of cattle (a) and sand (b) on maize area (modified from Odgaard et al., 2011). Colour legends illustrate temperatures ranging from relatively cool (blue) to relatively warm (red).

In conclusion, we recommend that statistical modeling of future land cover patterns and change includes these spatially-varying interactions of geophysical and socio-technical drivers. This will strengthen spatial modeling approaches used to refine our understanding of what drives land use and land cover patterns.

Read the full  open access paper:

Mette V. Odgaard, Tommy Dalgaard, Peder K. Bøcher Jens‐Christian Svenning. (2018). Site‐specific modulators control how geophysical and socio‐technical drivers shape land use and land cover. Geo: Geography and Environment. 2018;e00060

Opening-up (to) the politics of Anthropocene science

A group of scientists working for the International Commission on Stratigraphy recently recommended that the start of the Anthropocene epoch, an age defined by human impacts on the environment, be set at 1950. The concept of the Anthropocene has produced wide-ranging debates across the natural and social sciences. Here, Johannes Lundershausen , PhD candidate at the Tübingen Centre for Ethics, reflects on a recent dialogue in Geo between Mark Maslin and Andrew Barry

Geo: Geography and Environment recently published and thus fostered a timely dialogue between scientists researching the Anthropocene and scholars in science studies reflecting on the practice of this research (Barry and Maslin, 2016). The interlocutors in the published debate are physical geographer Mark Maslin, who has been actively involved in controversial debates between different research groups about the inception of the Anthropocene (Lewis and Maslin, 2015a), and human geographer Andrew Barry (both from University College London).

The starting point of their discussion is that the politics of the Anthropocene do not just relate to environmental governance but also to the ways in which this Epoch is formally defined by geoscientists. They highlight their disagreement about desirable interactions between the ‘formal’ geo-scientific assessment of the Anthropocene and the ‘informal’ engagements of social scientists with the concept. Whereas Mark Maslin holds that these academic realms should debate the Anthropocene in their own terms, Andrew Barry considers closer collaboration between disciplines essential to the study of the Anthropocene.

Copyright Smudge Studio

This difference is intriguing particularly because Maslin and Barry ostensibly agree on the need to ‘open up the geo-scientific debate about the Anthropocene to the social sciences’ and Barry acknowledges that Maslin has taken a step in this direction, for example in  a publication that he co-authored with UCL colleague Simon Lewis (2015b). Nevertheless, Maslin and Barry arguably mean different things when they talk about this interdisciplinary openness.

When prompted, Maslin draws a picture of interdisciplinarity in which social and natural science debates run parallel to each other. Social sciences, from this perspective, are expected to adapt to the requirements of the natural sciences in order to inform the latter about the consequences of their work as well as the social causes of environmental changes. Geoscientists, meanwhile, ‘should not be distracted by the […] valid discussions on the history and politics’ of the Anthropocene (p. 6). This way of ‘opening-up’ is reminiscent of the ‘subordination-service mode’ of interdisciplinarity that Barry and colleagues defined in a seminal paper in 2008 (Barry et al., 2008).

Barry himself comes closer to an ‘agonistic-antagonistic mode’ of interdisciplinarity in which the epistemological and ontological assumptions of established disciplines are challenged. He proposes a collaboration between the social and the geo-sciences that breaks with the existing disciplinary divisions of labour and involves the social sciences directly in the assessment of the merits of different proposals for an Anthropocene inception.

These two approaches, however, are more than different visions of interdisciplinarity. They also make for different ways of dealing with the topic of the debate, i.e. the politics of the Anthropocene, especially as they relate to geo-scientific definitions of the term. For Barry, interdisciplinarity can foster new conceptualisations of the role of politics in the geo-sciences and, reciprocally, the role of the geological in historical and political sciences; whereas for Maslin, interdisciplinary collaboration can or should not affect the constitution of geo-scientific practice.

Ultimately, it could be argued, the two approaches to interdisciplinarity are equipped to deal with very different conceptions of politics in the geo-sciences in particular, and in science more generally. Although Maslin recognizes politics in the interpretation and application of official criteria for establishing formal geological units, these politics are rather different from those that Barry refers to when he highlights the inherently political nature of, for example, applying scientific standards in practice, defining the scope of scientific controversies or deciding which parties are legitimately involved in such controversies (p. 3). Maslin views science as an ideally value-free endeavour in which clearly defined rules and epistemic standards guide the interpretation of data. This ideal is particularly apparent in his criticism of the members of the Anthropocene Working Group, who, he alleges, have been ‘swayed by political considerations’ in their interpretation of stratigraphic evidence (p. 4). Instead of following the remit of their work and keeping politics out of the geo-scientific definition of the Anthropocene, Maslin contends, they have acted as an advocacy group for a post-1945 inception of the Anthropocene.

This difference between Maslin’s ideal of value-free science and Barry’s insistence on the social and historical contingency of scientific practice raises questions about the initially proclaimed agreement of the two interlocutors about the existence of politics in Anthropocene geo-science. One particularly interesting question concerning this emerging disagreement is how to practically deal with social values in scientific practice (including, amongst others, political ones).

Scientists who operate under the ideal of value-free science tend to see social values in scientific practice as a threat to scientific integrity that opens the door to a politicisation of science. But in geo-scientific research on the Anthropocene, as Barry argues, scientific evaluations are underdetermined by evidence (and, I would add, also by epistemic values). In this situation, social values do not necessarily compete with geo-scientific evidence but they can work to complement the available geological evidence by guiding its interpretation and judging its power to support a given proposal for the inception of the Anthropocene.

Involving social scientists in geo-scientific debates, as suggested by Barry, might be a method of operationalising this indirect role of social values in Anthropocene science. I would argue that Maslin’s proposal to adopt public engagement strategies from climatologists, on the other hand, will not suffice to deal with the politics in Anthropocene science (cf. Beck, 2012), nor will his appeal reference to scientific objectivity, which other researchers, who he accuses of practicing politicised geo-science, equally claim for themselves (Zalasiewicz et al., 2015). Opening up to the idea of an appropriate place for social values in geo-scientific practice and the possibility of an interdisciplinary exchange that produces different scientific practices, arguably holds more potential to deal with the ‘mask[ed][…] political views’ (p. 9) and the ‘political ramifications’ (p. 4) that Maslin acknowledges. The question remains as to whether there are ways to do this while maintaining the ‘independence and credibility’ of geo-scientists (p.6) that Maslin calls for. Debates such as this, between physical and social scientists, are vital ways of moving this conversation forward.

Johannes Lundershausen is a PhD candidate at the Tübingen Centre for Ethics.

Barry A, Born G and Weszkalnys G (2008) Logics of interdisciplinarity. Economy and Society 37(1): 20–49.

Barry A and Maslin M (2016) The politics of the anthropocene: A dialogue. Geo: Geography and Environment 3(2): e00022

Beck S (2012) Between Tribalism and Trust: The IPCC Under the “Public Microscope”. Nature and Culture 7(2): 151–173

Lewis SL and Maslin MA (2015a) A transparent framework for defining the Anthropocene Epoch. The Anthropocene Review 2(2): 128–146

Lewis SL and Maslin MA (2015b) Defining the anthropocene. Nature 519(7542): 171–180.

Zalasiewicz J, Waters CN, Barnosky AD, Cearreta A, Edgeworth M, Ellis EC, et al. (2015) Colonization of the Americas, ‘Little Ice Age’ climate, and bomb-produced carbon: Their role in defining the Anthropocene. The Anthropocene Review 2(2): 117–127