**6. Acknowledgment**

16 International Perspectives on Global Environmental Change

Indeed, the concepts of detection and attribution7 – have clear shared meanings for both the political world and the scientific field, following the dialectics assumed by Giddens, in which the impact of the social sciences appears when "socio-scientific concepts [end up being selectively absorbed] by the social world, to which such concepts [become] a constitutive part" (2001: 112; my translation from the Brazilian edition). In addition, it can be observed that attribution of climate change to human action depends on the shared understanding of the uncertainties intrinsic to climate modelling. This dialectics is manifested in the importance attributed to detection and attribution in both the technical and the political discourses, which can be documented by the generalized and continuing use of these concepts, as central elements of both scientific investigation and political deliberation as can be found, for example, in Houghton & Morel (1984), Thatcher (1990), and

The role of the concept of emissions scenarios8 (i.e. scenarios of emissions of greenhouse gases as defined, for example, in IPCC, 2000), can be understood in similar terms. In this case, it also presents particular interest because it offers the prospect of descriptions of the future which would be immediately shared with the social world, but manifestly have not the status of predictions, since the result of the reproduction and evolution of the social world is admittedly uncertain for anyone. Emissions scenarios, more particularly, serve to at least two purposes – as qualitative narratives that can be associated to reference ranges of emissions necessary to parameterize GCM models, and as an idea reflecting the unpredictability of emissions

In comparison to other analyses, which put emphasis on the IPCC review procedures, for example, those assuming an "'Extended Peer Community' [where] various stakeholders with various perspectives [...] are brought into the dialogue assessing the input from science to decision-making" (Saloranta, 2001: 492), the double hermeneutic framework may consider that some core issues pertaining to IPCC work are not *a posteriori* deliberated by society. On the contrary, here it is assumed that shared concepts have emerged in a social world in which the scientists are embedded. The success in arriving at some shared concepts does not presupposes consensual, definite and comprehensive responses as a result of the production of "objective" knowledge by science, and the dialectics assumed by the double hermeneutics can potentially recognize situations of conflict, contradictions, and the result of different mobilizations in relation to the environmental change issue (e.g. Alves, 2008;

The societal and political aspects of the problem of the changing Earth System have represented a major challenge for both the development of Earth System studies and to consider the question about the societal responses to climate change. In such a context, the articulation between the natural and the social sciences is also seen as a significant challenge

7Here, detection will be understood as detection of climate change, in particular, temperature, and attribution as attributing climate change to specific causes, in particular, to anthropogenic greenhouse

8"Scenario is a plausible description of how the future may develop, based on a coherent and internally consistent set of assumptions about key relationships and driving forces. Note that scenarios are neither

in the scientific reports of IPCC WG1 (IPCC, 1990, 1996, 2001, 2007).

Alves, 2010; Schor, 2008; Shackley et al, 1998).

gas emissions (Houghton & Morel 1984; IPCC, 1990).

predictions nor forecasts." (IPCC, 1995: 33)

**5. Conclusion** 

produced by social systems for both the scientific field and the social world itself.

I would like to express my gratitude to the book editors, for the clear indication of the parts of the text that needed revision and clarification to be more intelligible to a larger, multidisciplinary audience of scientists, and to Josefina Moraes and Roberto Araújo for their comments and suggestions to an earlier version of this chapter. This work is the result of several years of investigating and teaching environmental, climate and land change topics at the National Institute for Space Research (INPE), and I am indebted to my post-graduate students and colleagues that have helped to discuss and develop these ideas.
