An Integrated Analysis of Regional Land-Climate Interactions

The intensity and spatial reach of contemporary human alterations of the Earths land surface are unprecedented. Land-use and land-cover change (LULCC) are among the most significant of these human influences. Many studies demonstrate the influence of LULCC on local and regional climate, which, when aggregated, may significantly alter the global climate. Meanwhile, climate change related to increased atmospheric concentrations of greenhouse gases is expected to considerably affect people and ecosystems due to altered temperature and precipitation patterns.

While significant research has focused on global climate modeling and socioeconomic factors influencing land-use change, an integrated assessment at the regional scale of coupled human-climatic systems is required to address the question, What is the magnitude and nature of the interaction between land use and climate change at regional and local scales? Through this research project, an international multidisciplinary team including social, ecological, atmospheric, and statistical scientists will address this question by exploring the linkages between two foci of global change research, LULCC and climate change.

A major goal of global change science is to obtain a more reliable estimation of future climatic conditions. This goal increasingly requires high-resolution regional scale climate modeling that includes feedbacks between the land and atmosphere. This project aims to complete the loop of land-use/climate/land-use impacts assessment. Its contribution is in analysis of the complex linkages among components, with special emphasis on the questions, how does land-use change affect climate and how will climate change affect land use? These linkages will be examined through analysis and modeling of agricultural systems, land-use change, the physical properties of land cover, and regional climate dynamics.

The study will focus on East Africa, which has broad ranges of ecosystems, tropical climatic conditions, and areas of rapid land use change as well as a population vulnerable to climatic variability. The project will integrate (1) future local-level climate scenarios derived from downscaling of global climate models; (2) information derived from detailed long-term case studies of LULCC and analyses of long records of observed climate; (3) models to project LULCC from local to regional scales; (4) analyses of time-series satellite imagery to translate the effects of LULCC on land surface characteristics; (5) net primary productivity simulations; and (6) climate information from a regional climate model parameterized using local land surface parameters. The culmination of the project will be a series of climate-land system feedback experiments identifying the magnitude and nature of interactions between land and climate dynamics at regional scales. The investigators will characterize these interactions in terms of the determining form of feedbacks, the strength of linkages, issues of spatial and temporal scales, and the effect of "tipping points" on climate-land interactions.

The project will make a significant contribution both to science and to policy. Its scientific importance lies in addressing the complex interactions and feedback between climate change and land-use change by integrating state-of-the-art methodologies and multidisciplinary approaches. It will explicitly address issues important to biocomplexity theory and complex system modeling, including feedback, thresholds, uncertainty, and non-linearity. These are inherent issues in linking information derived from a variety of models and case studies in order to understand the multi-scale dynamics associated with linking LULCC and climate change over time. The anticipated scientific findings and new methodologies will advance future climate change research at regional and global scales. With respect to application, the project will provide plausible scenarios of future climate change and its impacts upon the dominant livelihood systems of East Africa.

The team will work with policy-makers and other stakeholders, including farmers and herders, to assess the implications of these scenarios for future agricultural research and policy, conservation, and land-use planning in the region. The findings will be relevant to scientists and policy-makers in many other parts of the world who are concerned with the implications for society and environment of complex interactions between land use and climate. In addition to addressing many fundamental climatic, ecological and socioeconomic questions, the research will be tightly integrated with the education of students from elementary school to graduate school. It will provide capacity-building opportunities for young and mid-career American and African scientists as well as outreach to various stakeholders from local to international communities. This project is supported by an award resulting from the FY 2003 special competition in Biocomplexity in the Environment focusing on the Dynamics of Coupled Natural and Human Systems.