@article{fdi:010065524,
  title = {{C}limate and carbon cycle dynamics in a {CESM} simulation from 850 to 2100 {CE}},
  author = {{L}ehner, {F}. and {J}oos, {F}. and {R}aible, {C}. {C}. and {M}ignot, {J}uliette and {B}orn, {A}. and {K}eller, {K}. {M}. and {S}tocker, {T}. {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{U}nder the protocols of phase 3 of the {P}aleoclimate {M}odelling {I}ntercomparison {P}roject, a number of simulations were produced that provide a range of potential climate evolutions from the last millennium to the end of the current century. {H}ere, we present the first simulation with the {C}ommunity {E}arth {S}ystem {M}odel ({CESM}), which includes an interactive carbon cycle, that covers the last millennium. {T}he simulation is continued to the end of the twenty-first century. {B}esides state-of-the-art forcing reconstructions, we apply a modified reconstruction of total solar irradiance to shed light on the issue of forcing uncertainty in the context of the last millennium. {N}evertheless, we find that structural uncertainties between different models can still dominate over forcing uncertainty for quantities such as hemispheric temperatures or the land and ocean carbon cycle response. {C}ompared to other model simulations, we find forced decadal-scale variability to occur mainly after volcanic eruptions, while during other periods internal variability masks potentially forced signals and calls for larger ensembles in paleoclimate modeling studies. {A}t the same time, we were not able to attribute millennial temperature trends to orbital forcing, as has been suggested recently. {T}he climate-carbon-cycle sensitivity in {CESM} during the last millennium is estimated to be between 1.0 and 2.1 ppm degrees {C}-1. {H}owever, the dependence of this sensitivity on the exact time period and scale illustrates the prevailing challenge of deriving robust constraints on this quantity from paleoclimate proxies. {I}n particular, the response of the land carbon cycle to volcanic forcing shows fundamental differences between different models. {I}n {CESM} the tropical land dictates the response to volcanoes, with a distinct behavior for large and moderate eruptions. {U}nder anthropogenic emissions, global land and ocean carbon uptake rates emerge from the envelope of interannual natural variability by about year 1947 and 1877, respectively, as simulated for the last millennium.},
  keywords = {},
  booktitle = {},
  journal = {{E}arth {S}ystem {D}ynamics},
  volume = {6},
  numero = {2},
  pages = {411--434},
  ISSN = {2190-4979},
  year = {2015},
  DOI = {10.5194/esd-6-411-2015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010065524},
}