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

Zhang, J. Felzer, B.S., and Troy, T.J. , 2020. Projected changes of carbon balance in mesic grassland ecosystems in response to warming and elevated CO2 using CMIP5 GCM results in the Central Great Plains, USA. Ecological Modeling. 434: 109247.
Felzer, B.S. , 2019. Cleaner Air Is a Win-Win. Nature Climate Change.
Felzer, B.S.; Ember, C.; Cheng, R.; Jiang, M., 2019. The Relationships of Extreme Precipitation and Temperature Events with Ethnographic Reports of Droughts and Floods in Nonindustrial Societies. Weather, Climate, and Society, 12: 135-148.
Herbert, R.P., S.C. Peters, D.M. Nelson, & R.K. Booth, 2019. Light variability and mixotrophy: responses of testate amoeba communities and shell δ13C values to a two-year peatland shading experiment. European Journal of Protistology 67: 15-26.
Liu, B., R.K. Booth, J. Escobar, Z. Wei, B.W. Bird, A. Pardo, J.H. Curtis, & J. Ouyang, 2019. Ecology and paleoenvironmental application of testate amoebae in peatlands of the high-elevation Colombian páramo. Quaternary Research 1: 14-32. doi:10.1017/qua.2018.143.
Amesbury, M.J., Booth, R.K., et al., 2018. Towards a Holarctic synthesis of peatland testate amoeba ecology: Development of a new continental-scale palaeohydrological transfer function for North America and comparison to European data. Quaternary Science Reviews 201: 483-500.
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.
Felzer, B.S. and Jiang, M., 2018. Effect of land use and land cover change in context of growth enhancements in the United States since 1700: net source or sink?. JGR-Biogeosciences, https://doi.org/10.1029/2017JG004378.
Felzer, B.S. and Jiang, M., 2018. Effect of land use and land cover change in context of growth enhancements in the United States since 1700: net source or sink?. JGR-Biogeosciences.
Felzer, B.S. and Jiang, M., 2018. Effect of land use and lance cover change in the context of growth enhancements in the United States since 1700: net source or sink?. JGR-Biogeosciences.
Fischer, H. et al., 2018. Palaeoclimate constraints on the impact of 2ºC anthropogenic warming and beyond. Nature Geoscience 11: 474-485.
Gallego-Sala, A.V. et al., 2018. Latitudinal limits to the predicted increase of the peatland carbon sink with warming. Nature Climate Change 8: 907-913.
PAGES2k Consortium (Emile-Geay, J. and 95 co-authors), 2018. A global multiproxy database for temperature reconstructions of the Common Era. Scientific Data 4:170088 doi: 10.1038/sdata.2017.88.
Stelling, J.M., Z.C. Yu, J. Loisel and D.W. Beilman, 2018. Peatbank response to late Holocene temperature and hydroclimate change in the western Antarctic Peninsula. Quaternary Science Reviews 188: 77-89.
Williams, J.W, E.C. Grimm, J. Blois, D. Charles, E. Davis, S.J. Goring, R.W. Graham, A.J. Smith, M. Anderson, J. Arroyo-Cabrales, A.C. Ashworth, J.L. Betancourt, B.W. Bills, R.K. Booth, P. Buckland, B.B. Curry, T. Giesecke, S.T. Jackson, et al., 2018. The Neotoma Paleoecology Database: A multi-proxy, international community-curated data resource. Quaternary Research 89: 156-177.
Xia, Z.Y., Z.C. Yu, and J. Loisel, 2018. Centennial-scale dynamics of the Southern Hemisphere westerly winds across the Drake Passage over the past two millennia. Geology 47: 855-858.
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.
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.
Loisel, J., Z.C. Yu, D.W. Beilamn, K. Kaiser and I. Parnikoza, 2017. Peatland ecosystem processes in the Maritime Antarctic during warm climates. Scientific Reports 7: 12344: doi:10.1038/s41598-017-12479-0 .
Sahagian, D., 2017. Responding to climate change deniers with simple facts and logic. Eos Editor’s Vox, AGU, March 30, 2017.
Stocker, B.D., Z.C. Yu, C. Massa, and F. Joos. , 2017. Peatland and ice core data constraints on the timing and magnitude of CO2 emissions from past land use. Proceedings of National Academy of Sciences of the USA 144: 1492-1497..
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.
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., 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., 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.
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.
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/.
Yu, Z.C., D.W. Beilman and J. Loisel, 2016. Transformations of landscape and peat-forming ecosystems in response to late Holocene climate change in the western Antarctic Peninsula. . Geophysical Research Letters, 43: 7186–7195.
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..

Graduate Theses

Adam Benfield (M.S.), 2019. Late Holocene History and Environmental Controls of Distichia muscoides Dominated Peatlands in the Eastern Colombian Andes.
Advisor: Zicheng Yu
Matthew Huff (M.S.), 2019. A High-Resolution Paleoecological Perspective on Historical Fire Regimes in Great Lakes Barren Communities of Stockton Island, Wisconsin.
Advisor: Robert Booth
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).