1. 1. Galloway, J.N., W.H. Schlesinger, C.M. Clark, N.B. Grimm, R.B. Jackson, B.E. Law, P.E. Thornton, A.R. Townsend, and R. Martin, 2014: Ch. 15: Biogeochemical cycles. Climate Change Impacts in the United States: The Third National Climate Assessment. Melillo, J.M., Terese (T.C.) Richmond, and G.W. Yohe, Eds. U.S. Global Change Research Program, Washington, DC, 350-368. http://dx.doi.org/10.7930/J0X63JT0
2. 2. Kunkel, K.E., 2016: Update to data orginally published in: Kunkel, K.E., D. R. Easterling, K. Hubbard, K. Redmond, 2004: Temporal variations in frostfree season in the United States: 1895 - 2000. Geophysical Research Letters, 31, L03201. http://dx.doi. org/10.1029/2003gl018624
3. 3. Brown, D.G., C. Polsky, P. Bolstad, S.D. Brody, D. Hulse, R. Kroh, T.R. Loveland, and A. Thomson, 2014: Ch. 13: Land use and land cover change. Climate Change Impacts in the United States: The Third National Climate Assessment. Melillo, J.M., Terese (T.C.) Richmond, and G.W. Yohe, Eds. U.S. Global Change Research Program, Washington, DC, 318-332. http:// dx.doi.org/10.7930/J05Q4T1Q
4. 4. Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura, and H. Zhang, 2013: Anthropogenic and natural radiative forcing. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, and P.M. Midgley, Eds. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 659-740. http://www.climatechange2013.org/report/full-report/
5. 5. Ward, D.S., N.M. Mahowald, and S. Kloster, 2014: Potential climate forcing of land use and land cover change. Atmospheric Chemistry and Physics, 14, 12701- 12724. http://dx.doi.org/10.5194/acp-14-12701- 2014