20 Feb 2023
 | 20 Feb 2023
Status: this preprint is open for discussion and under review for Climate of the Past (CP).

Exploring Holocene temperature trends and a potential summer bias in simulations and reconstructions

Christian Wirths, Elisa Ziegler, and Kira Rehfeld

Abstract. Proxy-based reconstructions and climate model simulations of surface temperature trends during the Holocene disagree: While reconstructions show a cooling during the mid- and late Holocene, climate models show a continuous warming – a contradiction known as the Holocene temperature conundrum. Despite extensive research, the reason for the disagreement remains unclear. Both, missing processes in the models as well as biases in the proxies and the resulting reconstructions are possible sources of the conundrum. Here we compare our TransEBM v1.2 climate simulation as well as additional climate models of different complexity and Holocene temperature trends from the Temperature12k dataset (Kaufman et al., 2020b), with regards to model-data and model-model agreement. We show that models of all complexities disagree with mid-Holocene temperature trends in reconstructions and that this disagreement is almost independent of proxy and archive type. While, models show the highest agreement with summer temperature trends in reconstructions, our study shows that a trivial summer bias in proxies is not sufficient to explain the conundrum. Further effort to disentangle seasonal biases in proxies and the testing of potential misrepresentations in climate models, like anthropogenic land-use, in form of sensitivity experiments are needed to resolve the Holocene conundrum.

Christian Wirths et al.

Status: open (until 01 May 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-86', Anonymous Referee #1, 13 Mar 2023 reply
  • RC2: 'Comment on egusphere-2023-86', Anonymous Referee #2, 22 Mar 2023 reply

Christian Wirths et al.

Christian Wirths et al.


Total article views: 407 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
287 111 9 407 2 2
  • HTML: 287
  • PDF: 111
  • XML: 9
  • Total: 407
  • BibTeX: 2
  • EndNote: 2
Views and downloads (calculated since 20 Feb 2023)
Cumulative views and downloads (calculated since 20 Feb 2023)

Viewed (geographical distribution)

Total article views: 387 (including HTML, PDF, and XML) Thereof 387 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 29 Mar 2023
Short summary
We compare Holocene temperature trends from reconstructions and global climate models of different complexities. We find that models of all complexities disagree with mid-Holocene trends in reconstructions, and we show that this disagreement is largely independent of the type of reconstruction. From our results we conclude that a seasonal bias in the reconstructions is unlikely as a full explanation for the disagreement.