Kevin Schaefer

Research Scientist III


PhD, Colorado State University, 2004


Permafrost carbon feedback, modeling of the terrestrial biosphere, biogeochemistry, remote sensing of active layer thickness

Recent Highlights and Upcoming Expeditions

  • November 2012: Release of Policy Implications of Warming Permafrost for the United Nations Environmental Programme
  • August 2012: Schaefer traveled to the North Slope of Alaska to collect permafrost cores and perform active layer surveys.
  • July 2012: Schaefer published a paper in Nature Geoscience showing reduced carbon uptake during the 2000-4 drought in the western North America. The drought was the worst in 800 years and is expected to the dry end of a new mega-drought in the western United States (Schwalm et al., 2012).
  • April 2012: Paper published in Nature linking the sudden warming of the Palaeocene-Eocene Thermal Maximum (PETM) 55 million years ago to carbon dioxide and methane released from thawing permafrost in Antarctica (DeConto et al., 2012)

Current Research

  • We are currently quantifying the strength, timing, and dynamics of the permafrost carbon feedback. The permafrost carbon feedback is an amplification of surface warming from anthropogenic greenhouse emissions due to the release of CO2 and methane from thawing permafrost.
  • We are developing new remote sensing techniques to measure active layer thick-ness from space. Currently, the only way to measure active layer thickness is to go into the field and directly measure it using a metal probe.
  • We are exploring ways to improve the representation of various biogeochemical and physical processes in terrestrial biosphere models. We are organizing several Model Intercomparison Projects (MIPs) to compare model output against observations to identify the key model parameters or structures that drive model performance.


Schaefer is lead organizer of the North American Carbon Program (NACP) Site Synthesis. We are comparing simulated carbon fluxes from 21 models against observed carbon fluxes at 44 eddy covariance flux towers.

Member, American Geophysical Union (AGU)

Member, American Association for the Advancement of Science (AAAS)



Gonçalves de Gonçalves, L. G., J. S. Borak, M. H. Costa, et al. (including K. Schaefer). 2013. Overview of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia Data Model Intercomparison Project (LBA-DMIP). Agricultural and Forest Meteorology 182-183: 111-127, doi:10.1016/j.agrformet.2013.04.030.

Liu, L., K. Schaefer, A. Gusmeroli, G. Grosse, B. M. Jones, T. Zhang, A. D. Parsekian, and H. A. Zebker. 2013. Seasonal thaw settlement at drained thermokarst lake basins, Arctic Alaska. The Cryosphere Discussions 7: 5,793-5822, doi:10.5194/tcd-7-5793-2013.

Liu, S., Y. Wei, W. M. Post, R. B. Cook, K. Schaefer, and M. M. Thornton. 2013. The Unified North American Soil Map and its implications on the soil organic carbon stock in North America. Biogeosciences, doi:10:2,915-2,506.

Huntzinger, D. N., C. Schwalm, A. M. Michalak, K. Schaefer, et al. 2013. The North American Carbon Program Multi-scale synthesis and Terrestrial Model Intercomparison Project – Part 1: Overview and experimental design. 2013. Geoscientific Model Development Discussions 6: 3,977-4,008, doi:10.5194/gmdd-6-3977-2013.

Mishra, U., J. D. Jastrow, G. Hugelius, et al. (including K. Schaefer). 2013. Empirical estimates to reduce modeling uncertainties of soil organic carbon in permafrost regions: a review of recent progress and remaining challenges. Environmental Research Letters 8(3), doi:10.1088/1748-9326/8/3/035020.

Raczka, B. M, K. J. Davis, D. N. Huntzinger, et al. (including K. Schaefer). 2013. Evaluation of continental carbon cycle simulations with North American flux tower observations. Ecological Monographs, doi:10.1890/12-0893.1.

Stoy, P. C., M. Dietze, A. D. Richardson, et al. (including K. Schaefer). 2013. Evaluating the agreement between measurements and models of net ecosystem exchange at different times and time scales using wavelet coherence: an example using data from the North American Carbon Program Site-Level Interim Synthesis. Biogeosciences Discussions 10(2): 3,039-3,077, doi:10.5194/bg-10-2915-2013.

van der Velde, I. R., J. B. Miller, K. Schaefer, K. A. Masarie, S. Denning, J. W. C. White, P. P. Tans, M. C. Krol, and W. Peters. 2013. Biosphere model simulations of interannual variability in terrestrial 13C/12C exchange. Global Biogeochemical Cycles 27(3): 637-649, doi:10.1002/gbc.20048.


DeConto, R. M., S. Galeotti, M. Pagani, D. Tracy, K. Schaefer, T. J. Zhang, D. Pollard, and D. J. Beerling. 2012. Past extreme warming events linked to massive carbon release from thawing permafrost. Nature 484(7392), doi:10.1038/nature10929.

Keenan, T. F., I. Baker, A. Barr, P. Ciais, K. Davis, M. Dietze, D. Dragon, C. M. Gough, R. Grant, D. Hollinger, K. Hufkens, B. Poulter, H. Mccaughey, B. Raczka, Y. Ryu, K. Schaefer, H. Q. Tian, H. Verbeeck, M. S. Zhao, and A. D. Richardson. 2012. Terrestrial biosphere model performance for inter-annual variability of land-atmosphere CO2 exchange. Global Change Biology 18(6): 1971-1987, doi:10.1111/j.1365-2486.2012.02678.x.

Liu, L., K. Schaefer, T. J. Zhang, and J. Wahr. 2012 Estimating 1992-2000 average active layer thickness on the Alaskan North Slope from remotely sensed surface subsidence. Journal of Geophysical Research - Earth Surface 117, F01005, doi:10.1029/2011JF002041.

Richardson, A. D., R. S. Anderson, M. A. Arain, A. G. Barr, G. Bohrer, G. S. Chen, J. M. Chen, P. Ciais, K. J. Davis, A. R. Desai, M. C. Dietze, D. Dragoni, S. R. Garrity, C. M. Gough, R. Grant, D. Y. Hollinger, H. A. Margolis, H. McCaughey, M. Migliavacca, R. K. Monson, J. W. Munger, B. Poulter, B M. Raczka, D. M. Ricciuto, A. K. Sahoo, K. Schaefer, H. Q. Tian, R. Vargas, H. Verbeeck, J. F. Xiao, and Y K. Xue. 2012. Terrestrial biosphere models need better representation of vegetation phenology: results from the North American Carbon Program Site Synthesis. Global Change Biology 18(2): 566-584, doi:10.1111/j.1365-2486.2011.02562.x.

Schaefer, K., C. R. Schwalm, C. Williams, M. A. Arain, A. Barr, J. M. Chen, K .J Davis, D. Dimitrov, T. W. Hilton, D. Y. Hollinger, E. Humphreys, B. Poulter, B. M. Raczka, A. D. Richardson, A. Sahoo, P. Thornton, R. Vargas, H. Verbeeck, R. Anderson, I. Baker, T. A. Black, P. Bolstad, J. Q. Chen, P. S. Curtis, A. R. Desai, M. Dietze, D. Dragoni, C. Gough, R. F. Grant, L. H. Gu, A. Jain, C. Kucharik, B. Law, S. G. Liu, E. Lokipitiya, H. A. Margolis, R. Matamala, J. H. McCaughey, R. Monson, J. W. Munger, W. Oechel, C. H. Peng, D. T. Price, D. Ricciuto, W.J Riley, N. Roulet, H. Q. Tian, C. Tonitto, M. Torn, E. S. Weng, and X. L. Zhou. 2012. A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis. Journal of Geophysical Research - Biogeosciences 117, G03010, doi:10.1029/2012JG001960.

Schwalm, C. R., C. A. Williams, K. Schaefer, D. Baldocchi, T. A. Black, A. H. Goldstein, B. E. Law, W. C. Oechel, T. P. U. Kyaw, and R. L. Scott. 2012. Reduction in carbon uptake during turn of the century drought in western North America. Nature Geoscience 5 (8) 551-556, doi:10.1038/NGEO1529.

Sulman, B. N., A. R. Desai, N. M. Schroeder, D. Ricciuto, A. Barr, A. D. Richardson, L. B. Flanagan, P. M. Lafleur, H. Q. Tian, G. S. Chen, R. F. Grant, B. Poulter, H. Verbeeck, P. Ciais, B. Ringeval, I. T. Baker, K. Schaefer, Y. Q. Luo, and E. S. Weng. 2012. Impact of hydrological variations on modeling of peatland CO2 fluxes: Results from the North American Carbon Program site synthesis. Journal of Geophysical Research - Biogeosciences 117, G01031, doi:10.1029/2011JG001862.

Williams, C. A, M. Reichstein, N. Buchmann, D. Baldocchi, C. Beer, C. Schwalm, G. Wohlfahrt, N. Hasler, C. Bernhofer, T. Foken, D. Papale, S. Schymanski, and K. Schaefer. 2012. Climate and vegetation controls on the surface water balance: Synthesis of evapotranspiration measured across a global network of flux towers. Water Resources Research 48, W06523, doi:10.1029/2011WR011586.


Dietze, M. C., R. Vargas, A. D. Richardson, P. C. Stoy, A. G. Barr, R. S. Anderson, M. A. Arain, I. T. Baker, T. A. Black, J. M. Chen, P. Ciais, L. B. Flanagan, C. M. Gough, R. F. Grant, D. Hollinger, R. C. Izaurralde, C. J. Kucharik, P. Lafleur, S. G. Liu, E. Lokupitiya, Y. Q. Luo, J. W. Munger, C. H. Peng, B. Poulter, D. T. Price, D. M. Ricciuto, W. J. Riley, A. K. Sahoo, K. Schaefer, A. E. Suyker, H. Q. Tian, C. Tonitto, H. Verbeeck, S. B. Verma, W. F. Wang, and E. S. Weng. 2011. Characterizing the performance of ecosystem models across time scales: A spectral analysis of the North American Carbon Program site-level synthesis. Journal of Geophysical Research - Biogeosciences 116, G04029, doi:10.1029/2011JG001661.

Schaefer, K., T. J. Zhang, L. Bruhwiler, and A. P. Barrett. 2011. Amount and timing of permafrost carbon release in response to climate warming. Tellus 63(2): 165-180, doi:10.1111/j.1600-0889.2011.00527.x.

Schwalm, C. R., C. A. Williams, and K. Schaefer. 2011. Carbon consequences of global hydrologic change, 1948-2009. Journal of Geophysical Research - Biogeosciences 116, G03042, doi:10.1029/2011JG001674.

Schwalm, C. R., C. A. Williams, K. Schaefer, I. Baker, G. J. Collatz, and C. Rodenbeck. 2011. Does terrestrial drought explain global CO2 flux anomalies induced by El Nino? Biogeosciences 8(9): 2,493-2,506, doi:10.5194/bg-8-2493-2011.


Peters, W., M. C. Krol, G. R. van der Werf, S. Houweling, C. D. Jones, J. Hughes, K. Schaefer, et al. 2010. Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations. Global Change Biology 16(4): 1,317-1,337, doi:10.1111/j.1365-2486.2009.02078.x.

Schwalm, C. R., C. A. Williams, K. Schaefer, et al. 2010. Assimilation exceeds respiration sensitivity to drought: A FLUXNET synthesis. Global Change Biology 16(2): 657-670, doi:10.1111/j.1365-2486.2009.01991.x.


Lokupitiya, E. S. Denning, K. Paustian, I. Baker, K. Schaefer, S. Verma, T. Meyers, C. J. Bernacchi, A. Suyker, and M. Fischer. 2009. Incorporation of crop phenology in simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands. Biogeosciences (6): 969-986.

Schaefer, K., T. Zhang, A. G. Slater, L. Lu, A. Etringer, and I. Baker. 2009. Improving simulated soil temperatures and soil freeze/thaw at high-latitude regions in the Simple Biosphere/Carnegie-Ames-Stanford Approach model. Journal of Geophysical Research 114, F02021, doi:10.1029/2008JF001125.


Schaefer, K., G. J. Collatz, P. Tans, A. S. Denning, I. Baker, J. Berry, L. Prihodko, N. Suits, and A. Philpott. 2008. Combined Simple Biosphere/Carnegie-Ames-Stanford Approach terrestrial carbon cycle model. Journal of Geophysical Research 113, G03034, doi:10.1029/2007JG000603.


Schaefer, K., T. Zhang, P. P. Tans, and R. Stöckli. 2007. Temperature anomaly reemergence in seasonally frozen soils. Journal of Geophysical Research 12, D20102, doi:10.1029/2007JD008630.


Schaefer, K., A. S. Denning, and O. Leonard. 2005. The winter Arctic Oscillation, the timing of spring, and carbon fluxes in the Northern Hemisphere. Global Biogeochemical Cycles 19, GB3017, doi:10.1029/2004GB002336.


Schaefer K., A. S. Denning, and O. Leonard. 2004. The winter Arctic Oscillation and the timing of snowmelt in Europe. Geophysical Research Letters 31(22), L22205.


McNoldy, B., A. Chen, Z. Eitzen, R. Moore, J. Persing, K. Schaefer, and W. Schubert. 2003. Design and construction of an affordable rotating table for classroom demonstrations of geophysical fluid dynamics principles. Bulletin of the American Meteorological Society 84(12): 1,827-1,834, doi:10.1175/BAMS-84-12-1827.

Schaefer, K., A. S. Denning, N. Suits, J. Kaduk, I. Baker, S. Los, and L. Prihodko. 2002. Effect of climate on interannual variability of terrestrial CO2 fluxes. Global Biogeochemical Cycles 16(4), doi:10.1029/2002GB001928.

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Related Resources

Cooperative Institute for Environmental Sciences (CIRES)