tag:blogger.com,1999:blog-4142988674703954802.post3365728745055891117..comments2024-03-11T04:54:26.827-07:00Comments on THE HOCKEY SCHTICK: New paper finds Arctic sea ice was much less than present-day during the Holocene Climate Optimum ~6,000 years agoUnknownnoreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4142988674703954802.post-19560525564186332802014-12-21T09:23:07.281-08:002014-12-21T09:23:07.281-08:00From the paper...
http://www.sciencedirect.com/sc...From the paper...<br /><br />http://www.sciencedirect.com/science/article/pii/S0277379113004162?np=y<br />The present study points at a potentially large impact of the increased SW [short wave solar radiation] forcing during EHIM [Early Holocene Insolation Maximum, 9,000 to 6,000 years ago] through the surface albedo feedback, leading to a breakdown of the perennial sea ice cover into a state dominated by ice free summers. Above we have discussed some mechanisms and feedback processes that are not included in the present model study. Although some of the in this model omitted mechanisms are believed to be important (e.g. the surface albedo feedback associated with vegetation) the current understanding of the climate system as a whole is far from complete. Evidence of problems with the coupled GCMs [models] can be found in the PMIP [models of paleoclimate] literature. For instance Jiang et al. (2012) show that 35 out of 36 PMIP models produce colder than present day climate in China during mid-Holocene which is in stark contrast to available multiproxy data for the same time and region indicating 1–5 °C warmer than present day conditions. Suffice to say that further research on the coupled global climate system is needed before any conclusive results regarding the evolution of the Arctic sea ice cover during Holocene can be reached through climate modelling.<br /><br />Several studies suggest that the GHG concentrations were lower during the [Early Holocene Insolation Maximum, ∼ 9,000 years ago] (Indermuhle, 1999, Brook et al., 2000 and Sowers et al., 2003). However, when running the model with GHG [greenhouse gas] concentrations estimated from paleo-proxy data (LeGrande and Schmidt, 2009) for 9000 years BP [before present] yields only a moderate effect on the ice cover thickness of typically ∼0.1 m. This is consistent with the results of CAPE Project members (2001) showing also only marginal effects of the GHG [greenhouse gas] concentration variations on the Arctic climate. <br />Kenneth Richardhttps://www.blogger.com/profile/00198431792165032103noreply@blogger.comtag:blogger.com,1999:blog-4142988674703954802.post-83697741175547254152014-03-24T01:28:58.955-07:002014-03-24T01:28:58.955-07:006000 years ago? Isn't that when the Pope, The ...6000 years ago? Isn't that when the Pope, The Mufti in Iran, the late Osama Bin Laden and all the other religious Global Warming Nuts believe the earth was created? Mrs. EntryReqrdhttps://www.blogger.com/profile/07529284216248692343noreply@blogger.com