15. Modeling environmental responses to combinations of changes in climate and land use
There is growing concern among policy makers, land and resource managers, and the general public about the potential effects of global warming on the environment and about the resources necessary for our society to thrive. The international community has sponsored a rigorous examination of the causes, mechanisms, and possible climatic consequences of this warming (IPCC 2007), and there are numerous efforts to model these consequences at both global and regional scales. Although these studies are important, they do not yet account for the possible concomitant effects of human land use. The effects of climate change and variability are significantly amplified by land use threats. Land use change, including disturbances and intensification, may alter water quality and quantity, encourage the spread of invasive species, and alter habitat connectivity. For example, National Wildlife Refuges are being impacted by high rates of land use change along their margins, such as biofuels development on the Great Plains, the spread of pine plantations in the Southeast, and increased urbanization in western and coastal regions. Future environmental conditions will be some combination of the effects of changes in climate and in land use, and we seek to develop methodologies that will permit us to assess the consequences of these combined effects.
The objective of this postdoctoral position will be to work with USGS scientists to develop a framework and the capacity to construct scenarios of change that are driven by the combination of climate change and land use. This work will focus on two to four regions within the United States that have different climatic conditions and different potential trajectories of land use change. The initial regions to be considered for further research are: the Mid-Atlantic region (forest giving way to urbanization under a wet climate), the Upper Midwest (high intensity agriculture), the Upper Colorado River Basin (high proportion of Federal lands in a semiarid context), and the Central Valley of California (agricultural region giving way to increasing urbanization). Global climate model simulations will be selected from the new IPCC (2007) AR4 results that represent high, medium, and low greenhouse emissions levels. For each set of emissions-level simulations, the land surface characteristics will be changed to portray a range of possible land use schemes as projected by models developed at the EROS Data Center. These scenarios will then be used as the bases for simulating potential consequences for ecosystems, species’ distributions, and water resources in each of the selected regions.
Scenarios from the same models used in the IPCC studies will be examined for the present and for two intervals of the past. Model simulations from the early and middle Holocene, when solar radiation in Northern Hemisphere summer was greater than it is today, provide insights into warmer climates (but with greenhouse gases at levels near those before the industrial revolution). We will compare the results of these simulations with paleoenvironmental studies to assess how well the models simulate climates that were different from those of today. The second examination of the past will focus on the effects of changes in land use and land cover since the arrival of western civilization using model simulations with greenhouse gases held constant but with the present-day land cover replaced by reconstructed land cover for the immediate pre-contact period.
Proposed Duty Station: Denver, CO
Areas of Ph.D.: Geology, geography, hydrology
Qualifications: Applicants must meet one of the following qualifications: Research Geologist, Research Geographer, Environmental Scientist
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)
Research Advisor(s): Robert Thompson, (303) 236-5347, rthompson@usgs.gov; Thomas Loveland, (605) 594-6066, loveland@usgs.gov; Gary Clow, (303) 236-5509, clow@usgs.govHuman Resources Office contact: Kathleen Scheich, (303) 236-9581, kscheich@usgs.gov
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Summary of Opportunities |