The Holocene temperature conundrum

Liu, Z., Zhu, J., Rosenthal, Y., Zhang, X., Otto-Bliesner, B. L., Timmerman, A., Smith, R. S. ORCID: https://orcid.org/0000-0001-7479-7778, Lohmann, G., Zheng, W. and Timm, O. E. (2014) The Holocene temperature conundrum. Proceedings of the National Academy of Sciences of the United States of America, 111 (34). E3501-E3505. ISSN 0027-8424 doi: 10.1073/pnas.1407229111

Abstract/Summary

A recent temperature reconstruction of global annual temperature shows Early Holocene warmth followed by a cooling trend through the Middle to Late Holocene [Marcott SA, et al., 2013, Science 339(6124):1198–1201]. This global cooling is puzzling because it is opposite from the expected and simulated global warming trend due to the retreating ice sheets and rising atmospheric greenhouse gases. Our critical reexamination of this contradiction between the reconstructed cooling and the simulated warming points to potentially significant biases in both the seasonality of the proxy reconstruction and the climate sensitivity of current climate models.