Uncertainty, and how to communicate it to policy makers, is of growing concern in global change research (Dessaia et al., 2007). But whereas in the field of climate change the primary source of uncertainty is about the future, for desertification even past and present trends are highly inaccurate and strongly contested. Nevertheless, the two are related, since uncertainty about past and present trends in terrestrial variables included in global climate models affects uncertainty about future trends in climate and their impacts on the planet and its inhabitants.
So surely anything that scientists can do to use remote sensing and field observations to improve our knowledge of it must be a good thing and improve implementation of the UN Convention to Combat Desertification (CCD)? In practice, things are not as simple as this. I argue in this paper that uncertainty, and the ability of scientists and policy makers to reduce it, are connected in complex ways. That scientific uncertainty is not autonomous but socially constructed and politically contingent has been recognized for some time (Wynne, 1992).
The first part of the paper looks at the relationship between uncertainty and constraints on communication between scientists and policy makers in the desertification regime, which consists of the binding CCD and the voluntary Plan of Action to Combat Desertification (PACD) which preceded it. This discussion is informed by reference to the Boundary Organization Model. The second part of the paper fits these constraints into a broader picture of uncertainty, framed by reference to the concept of post-normal science and a new Knowledge-Action Framework of science-policy communication. All three conceptualizations help scientists to stand back and view their roles as actors within the wider knowledge system' of desertification.
