Introduction

The theme of ‘human-landscape interactions’ in the twenty-first century covers a number of very exciting new developments, insights, and debates in the fields of environmental history, palaeoenvironmental reconstruction, and landscape archaeology. The field of landscape archaeology is relatively recent and many of the baseline concepts currently used to address human-landscape interactions were not developed until the 1970s. In the last 5 years, a confluence, or parallel maturation, has taken place between advances in archaeological theory, evolution of new high-resolution palaeoenvironmental sequences, and the emergence of new geospatial technologies.

This survey first summarizes background assumptions and concepts underpinning modern approaches, highlights the major debates and areas of innovation about climate change, environmental causality and new research directions, and lines of investigation that have come to light as a result of these new insights. Then, in light of these developments, this article suggests several theoretical and applied technology avenues for future investigation in landscape archaeology.

From a pre-World War II (WWII) focus on individual archaeological sites as isolated entities, archaeology has moved to their treatment as parts of a broader network of interrelated sites. More recently (post-1970s), the discipline has incorporated the idea of environmental setting for a contextual treatment of archaeological data. Within only the last decade, the emergence of new high-resolution dating and analysis techniques has begun to yield important new sequences of environmental change. These have done nothing less than revolutionize traditional approaches to the study of man-landscape interactions in prehistory and history.

Archaeology has only recently begun to grapple with the fact that these ‘environmental contexts’ are neither static nor constant. Rather, they are almost continuously changing, both independent of, and in response to, human interaction with the environment. As discussed below, recent advances and initiatives are beginning to transform the field from a two-dimensional (2D), mostly static approach (i. e., from solely a diachronic sequence of transformations out of context) to a dynamic, three-dimensional (3D) treatment of archaeological data in a geospatial universe. In fact, such a geospatial perspective will increasingly incorporate both the environmental diversity of past landscapes together with processes of climatic and environmental change and transformation.

Technologically, the advent of such tools as highly resolved, decade-level sampling and dating capabilities, geographic information systems (GIS), and 3D modeling of ancient and modern landscapes, from real world bathymetric and topographic sources, provides the means to dynamically analyze and describe complex geospatial relationships between man and the landscape. This emerging integration of the concept of environmental change, spurred by high-resolution dating techniques and sophisticated 3D real world geospatial data control, is reorienting the field of landscape archaeology from a ‘flat’ 2D universe (as in flat paper maps) into the third dimension which is continuously changing in form and resource potential through time. These new 3D geospatial technologies are providing archaeology with the means to plan, target, and discover surviving (and often well-preserved) archaeological remains. These applied technology solutions are leading to the discovery of well-preserved high-integrity remains, even in heavily altered, or now inundated or land-filled, modern landscapes - based on what the environment used to look like, instead of what it looks like today.

Recent discoveries and debates dominate in five areas of concern, not all complementary or consistent in their findings: (1) the recognition of magnitude and effect of long-term human impacts to the environment; (2) the effect of climate change on human settlement and land use history; (3) the advent and relevance of high-resolution dated sequences of environmental change; (4) very recent recognition of the critical role played by sea-level rise in human history in general, and in the origins of early urbanism in particular; and (5) new insights into the previously ignored significance and potential for archaeological preservation in inundated coastal estuaries, bays, and marshes. In essence, this article is not about ‘global warming’ per se - it is in addition to it.

Most new developments in landscape archaeology, or as some now refer to as landscape ecology and/or paleoecology, stem from the use of new high-resolution palaeoenvironmental pollen, ice or soils sequences to argue that significant environmental and climatic events occurred immediately before or after major changes in settlement patterns, economies or demographics of prehistoric cultures. Instead of studying periods spanning hundreds or even thousands of years, current breakthroughs in both New World and Old World archaeology reflect a shift to new high-resolution temporal and analytical sampling units of 20-50 years, or less.

The most current topic of debate is interpreting the role of climate change in general and the impact of droughts, in particular. As summarized below, droughts have been blamed for the demise of important cultural phases in Egypt, Mesopotamia, the American Southwest, Mexico, the Mayan area, and Andean South America. Similarly, others have argued that droughts were the incentives, or triggers, for early sedentary, centralized settlements and stratified societies. Several theorists and practitioners argue strongly for or against the existence and reality of catastrophic floods in prehistory. And the newest model for the emergence of Mesopotamian civilization highlights the role of sea level rise. As a counter to the often deterministic tone of many of these arguments, several cases highlight the role of past human cultures in bringing about significant, ecologically traumatic, long-term changes to prehistoric and early historic environments. Finally, in response to the recent recognition of the role of Late Holocene sea-level rise, or marine transgression, this overview will conclude with a discussion of the archaeological potential and significance of now buried and/or inundated landscapes, and of the geospatial tools that are being deployed to reveal them.