such as criminology or political science to the environmental sciences such as climatology or ecology. They are an absolute necessity if scientific understanding is to be translated into effective evidence-based and place-based policy, and if the average citizen is to become fully informed and engaged in discussions about potential uses and abuses of geographical technologies.

Earth observing satellites provide powerful observations of the physical parameters that characterize the Earth system, including sea-surface temperatures, rainfall, and land cover. Geographical scientists have benefited from the massive investments that have been made not only by U.S. government agencies, but also by the private sector and by agencies in other countries. They have discovered effective means of turning raw sensor measurements into characterizations of the land surface, and have applied these in numerous ways, many of them discussed in other chapters of this report (e.g., Chapters 2, 3, and 4). However, many of the social aspects of the Earth system cannot be observed or measured from above, and understanding of them must therefore rely on people’s willingness to divulge sensitive information about themselves in programs such as the U.S. Census.


The activity of describing and drawing the world—the literal root of the term geography—has changed dramatically over the centuries. An editorial in Nature (Editorial, 2008) went so far as to argue that our museum collections are full of specimens collected at vaguely recorded locations (Guo et al., 2008), but there is now no longer any excuse for not recording the location of any scientific observation made of phenomena on or near Earth’s surface. For many researchers much of the science of cartography, or the drawing of maps that accurately convey knowledge, has been encapsulated in a series of default options in software. Access to the products of remote sensing, once a task requiring a great deal of technical knowledge, is now reduced for many users to the manipulation of the simple user interface of a desktop or laptop computer, or even a hand-held PDA (personal digital assistant).

However, although it has undoubtedly become easier to work with geographical data and tools, we should not confuse the act of “describing and drawing” phenomena with the geographical knowledge and understanding that are embedded in today’s tools and data acquisition systems, or with the processes of reasoning and inference that translate raw observations into scientific knowledge and ultimately into improved decisions. Even though it is possible to make a decent-looking and informative map by doing no more than accepting the default options of a software package, the science of cartography is still an active field. Remote sensing, a workhorse of modern geographical data acquisition, continues to advance, making use of new kinds of sensors that exploit different parts of the electromagnetic spectrum, access a broader range of acoustic frequencies in the case of marine remote sensing, and achieve finer levels of spatial, temporal, or spectral resolution, and each new development opens opportunities for research into additional applications in the geographical sciences.

None of these developments, however, has in any way reduced the importance of expertise in reasoning and inference, and it is clearly in this area that the role of the geographical scientist is most critical (Longley et al., 2005). No one would suggest, for example, that technology has in any way reduced the need for expert pedologists, both as creators of knowledge about soils and as interpreters of that knowledge to users, even though that knowledge may be expressed through the simple medium of a map. Similarly the expertise of the cultural geographer in observing and interpreting the human landscape can never be encapsulated in software. Geographical scientists understand the nature of particular classes of phenomena through their training and knowledge of the literature. They are aware of the importance of spatial concepts such as scale, location, place, and interaction (Gersmehl, 2005); are familiar with their underlying theories and the pitfalls associated with each; and are capable of making effective use of the geographical data and tools at their disposal to augment the sum of human knowledge about the geographical landscape, while remaining cognizant of the inevitable uncertainty associated with that knowledge.

Past investments in research into geographical data and tools have produced dramatic progress. The stunning zooms and pans of the virtual globes rely on fundamental research by geographical scientists into ways of capturing the curved surface of the planet in digital form, a research area known as discrete global

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