Environmental Change

Critical Zone and Global-Change Research

What we do

The environmental-change group studies contemporary surface processes, past environments, and the future of the Earth system. This group has two interrelated focuses; we operate in the critical zone, where physical, chemical, hydrologic, geological, and biological processes interact, to better understand the functioning of the Earth system. We also use our understanding of modern processes and patterns to uncover the impacts of global change. We work closely with one another and encourage students to develop projects that take advantage of our complementary interests.

Critical Zone:  Hydrology, Geomorphology, Geochemistry, and Biogeochemistry

Our research in the critical zone seeks to understand how the Earth system “works.” Our modern-process studies use instrumental and sampling data that measure ecological, biogeochemical and climatic parameters at field sites. We integrate these data using computational models and laboratory experiments to develop a more complete understanding of the structure and function of the critical zone. Ongoing projects include snowmelt hydrology, stream restoration, fate and transport of metals, mineral weathering, soil formation, ancient and modern Mars surface environments, microclimate weather stations in Antarctica, carbon cycling in temperate forests and global peatlands.  We emphasize course work in the disciplines of ecology, hydrology, glaciology, geochemistry, meteorology, and stable isotopes. Our research takes place in field locations across the globe, including Alaska, the Yukon, the Rocky Mountains, the Appalachians, Crete, South America, and the western Antarctic Peninsula.

Global Change: Ecology, Climatology, and Paleoclimatology

The Global Change group is interested in understanding the patterns and processes of natural and human-induced environmental changes at annual to millennial timescales. We employ multidisciplinary approaches to examine recent and ongoing changes in ecosystems, derive biological, geochemical, and geological proxy records from natural archives preserved in lakes, peatlands, glaciers, corals, and caves, and use computational modeling to understand recent historical processes and formulate predictions about the future. Our current research interests seek to understand global change through documenting the temporal and spatial patterns of hydroclimate variability, biological community and ecosystem responses to climate variability, peat carbon storage, geochemical and magnetic records, and through Earth system modeling, and understanding internal feedbacks. Faculty work with students on research projects in many locations, including the Great Lakes region, northeastern North America, Alaska, the Yukon, the Tibetan Plateau and northwest China, Patagonia, the western Antarctic Peninsula, and the Peruvian Andes.

Research Facilities

We have excellent field, laboratory and computational facilities to conduct research in hydrology, ecology, paleoecology, geochemistry, environmental magnetism, climate modeling, ecosystem modeling, GIS and remote sensing. Field equipment includes peat and sediment corers, field deployed datasondes, and automatic water sampling systems. General lab facilities are used for carbon and sediment analysis, sample processing, and optical and SEM/EDS analysis. Mass spectrometers and cavity ring-down instruments are available for stable isotope determination of C, O, H, and N, with ICP-MS for general aqueous chemistry. Magnetic analysis facilities include a cryogenic magnetometer in a field free room and a selection of demagnetization systems.  Computational facilities include high-performance parallel clusters for climate models, and individual workstations for processing satellite remote sensing and GIS data.

If you're interested in graduate work at Lehigh, start here for links to the research we do, and then learn more about our graduate curriculum and our admissions procedures. More than anything, we encourage you to contact the person or persons you're interested in working with.



Recent Environmental Change Publications

Bebout, G. E., Banerjee, N. R., Izawa, M. R. M., Kobayashi, K., Lazzeri, K., Ranieri, L., and Nakamura, E., 2018. Nitrogen concentrations and isotopic compositions of seafloor-altered terrestrial basaltic glass: Implications for astrobiology. Astrobiology, v. 18, no. 4, DOI: 10.1089/ast.2017.1708.
D. Sahagian, 2018. Cobalt Key to Development of Early Life on Earth. Editors’ Highlights, Eos.
Anderson, L. D., Bebout, G. E., Izawa, M. R. M., Bridge, N. J., and Banerjee, N. R., 2017. Chemical alteration and preservation of sedimentary/organic nitrogen isotopic signatures in a 2.7 Ga seafloor volcanic sequence. International Journal of Astrobiology.
D. Sahagian, 2017. Responding to climate change deniers with simple facts and logic. Eos Editor’s Vox, AGU, March 30, 2017.
Jiang, M., Felzer, B.S., Nielsen, U. and Medlyn, B. , 2017. Biome-specific climatic space defined by temperature and precipitation predictability. Global Ecology and Biogeography, DOI:10.1111/geb12635.
Lazzeri, K. E., Bebout, G. E., and Geiger, C.A., 2017. Nitrogen and carbon concentrations and isotopic compositions of the silica clathrate melanophlogite. American Mineralogist, v. 102, p. 686–689.
Booth, R.K., A.W. Ireland, K. LeBoeuf, & A. Hessl, 2016. Late Holocene climate-induced forest transformation and peatland establishment in the central Appalachians.. Quaternary Research 85: 204-210.
D. Sahagian, 2016. The Proof of our Science Lies in the Telling. Eos Editor’s Vox, AGU, Feb. 8, 2016.
Jiang, M., B. Felzer and D. Sahagian, 2016. Predictability of precipitation over the conterminous U.S. Based on the CMIP5 Multi-Model Ensemble.. Nature- Sci. Rep. 6, 33618.
Jiang, M., B. Felzer and D. Sahagian, 2016. Characterizing predictability of precipitation means and extremes over the conterminous United States. 1949-2010, J. Climate, 29, 2621-2633.
Jiang, M., Felzer, B.S., and Sahagian, D., 2016. Predictability of precipitation over the conterminous U.S. based on the CMIP5 multi-model ensemble. J. Climate, doi:10.1038/srep29962. http://www.nature.com/articles/srep29962.
Jiang, M., Felzer, B.S., and Sahagian, D., 2016. Characterizing predictability of precipitation means and extremes over the conterminous United States, 1949-2010. J. Climate, http://dx.doi.org/10.1175/JCLI-D-15-0560.1.
Tian, H., Ren, W., Tao, B., Sun, G., Chappelka, A., Wang, X., Pan, S. Yang, J., Liu, J., Felzer, B., Melillo, J., and Reilly, J., 2016. Climate extremes and ozone pollution: a growing threat to China’s food security. Ecosystem Health and Sustainability. doi:10.1002/ehs2.1203/.
Zhang, J. Felzer, B.S., and Troy, T.J., 2016. Extreme precipitation drives groundwater recharge: the Northern High Plains Aquifer, Central United States, 1950-2010. Hydrological Processes, doi:10/1002/hyp.10809.
Andrews, T.A., and Felzer, B.S., 2015. Very-heavy precipitation in the greater New York City region and widespread drought alleviation tied to western US agriculture. PLOS ONE10(12): doi10.1371/journal.pone.0144416.
Burrows, J.E., Peters, S.C., 2015. Temporal and geochemical variations in above- and below-drainage coal mine discharge. Applied Geochemistry Special Issue Dedicated to Kirk Nordstrom. doi:10.1016/j.apgeochem.2015.02.010.
Clifford, M.J. and R.K. Booth, 2015. Late-Holocene drought and fire drove a widespread change in forest community composition in eastern North America. The Holocene 25: 1102-1110.
Gallen, S.F., Pazzaglia, F.J., Wegmann, K.W., Pederson J.L., and Gardner, T.W., 2015. The dynamic reference frame of rivers and apparent transience in incision rates. Geology, doi: 10.1130/G36692.1..
A. Bodzin, D. Anastasio, D. Sahagian, T. Peffer, C. Dempsey, and R. Steelman-Couch,, 2014. Investigating Climate Change Understandings of Urban Middle School Students. Jour. Environ. Education, 62, 417-430.
Dangal, S. R. S., Felzer, B. S., and Hurteau, M. D., 2014. Effects of agriculture and timber harvest on carbon sequestration in the eastern US forests.. Journal of Geophysical Research.
Felzer, B. and Sahagian, D, 2014. Climate impacts on regional ecosystem services in the United States from CMIP3-based multimodel comparisons. Climate Research.
Gunderson, K. L., Pazzaglia, F. J., Picotti, V., Anastasio, D. J., Kodama, K. P., Rittenour, T., Frankel, K. F., Ponza, A., Berti, C., Negri, A., and Sabbatini, A., 2014. Unraveling tectonic and climatic controls on synorogenic stratigraphy. Geological Society of America Bulletin, 126, 532-552..
He, Y., Jones, M., Zhuang, Q., Bochicchio, C., Felzer, B.S., Mason, E. and Yu, Z,, 2014. Evaluating the effects of climate seasonality on CO2 and CH4 cycling of Alaskan Ecosystems during the Holocene Thermal Maximum. Quaternary Science Reviews..
Jiang, M., Felzer, B., Hargreaves, B., and Zhang, J, 2014. Parameterization and sensitivity analysis of a biogeochemical model for Pennsylvania dairy pasture carbon flux under climate change scenarios.. Crop Science.
Loisel, J.*, Yu, Z.C., 2014. A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation. The Holocene, 24,1028-1042..
Ruegg, J., Gries, C., Bond-Lamberty, B., Bowen, G.J., Felzer, B.S., McIntyre, N.E., Soranno, P.A., Vanderbilt, K.L., and Weathers, K.C. , 2014. Closing the data life cycle: Using information management in macrosystems ecology research. Frontiers in Ecology and the Environment. 12(1): 24-30.

Graduate Theses

Jien Zhang (Ph.D.), 2017. Detection and Effects of Climate Extremes on Hydrology and Ecosystems: Case Studies in California and the Great Plains, USA.
Laura Markley (M.S.), 2017. “Characterization of the Goethite-Hematite ratio in Paleosols in the Mid-Atlantic Region as a Paleoprecipitation Proxy”.
Advisor: Steve Peters
Rebecca Whiteash (M.S.), 2017. Mercury Bioavailability Positively Correlated to The Mercury:Sulfur Ratio of Dissolved Organic Matter in Oxic Environments.
Advisor: Donald Morris
Robert Mason (M.S.), 2017. “A High-Resolution Paleoecological Perspective on Temperature Oak Forest Dynamics: Implications for Understanding Contemporary Oak Decline”.
Advisor: Robert Booth
Rui Cheng (M.S.), 2017. “Associated effect of temperature and soil moisture on summer forest carbon fluxes in the contiguous US”.
Jien Zhang (Ph.D.), 2016. Detection and Effects of Climate Extremes on Hydrology and Ecosystems: Case Studies in California and the Great Plains, USA.
Michael Clifford (Ph.D.), 2016. Late Holocene drought, fire, and vegetation in northeastern North America inferred from peatland archives.
Advisor: Robert Booth
Minkai Jiang (Ph.D.), 2016. On the history and evidence of the Colwell index in quantifying environmental predictability, and its applications in characterizing precipitation predictability in the conterminous United States.
Nathan Hopkins (Ph.D.), 2016. Magnetic till fabric: Applications of anisotropy of magnetic susceptibility (AMS) to subglacial deformation of till and ice.
Andrews, T. (Ph.D.), 2015. Why precipitation and forest structure are changing in the eastern US: insight from analysis of large empirical and climate model datasets.
Cleary, K. (M.S.), 2015. Carbon sequestration implication of shrub expansion, peat initiation, and sphagnum growth in Arctic Tundra on the north slope of Alaska.
Advisor: Zicheng Yu
Henry, J.E. (Ph.D.), 2015. Geochemical factors controlling the fate of Fe, Al, and Zn in coal-mine drainage in the Anthracite Coal Region, Pennsylvania, USA.
Advisor: Steve Peters
Navara, C.E. (M.S.), 2015. The Effects of interspecific interactions on reproductive success of Carolina chickadees (Poecile carolinensis). (coadvised: Booth and Rice).
Blake, J.M.T. (Ph.D.), 2014. Geologic, tectonic, and geochemical signatures leading to arsenic in groundwater in the Gettysburg Basin.
Advisor: Steve Peters
Leboeuf, K.A. (M.S.), 2014. Holocene Vegetation, Hydrology, and Fire in the North-Central Adirondacks of New York.
Advisor: Robert Booth
Spicer, M.E. (M.S.), 2014. The legacy of planting: A century-long experiment in forest development at Lehigh University.
Advisor: Robert Booth