Open triangles come from the marine alkenone method, open squares from traditional stomatal approaches, open pentagon (partially covered) from the paleosol carbonate method, and open circle from the alternative gas-exchange model of Konrad et al. CO 2 site mean reconstruction from Napartulik (Nunavut, Canada) is shown in black error bars for CO 2 are the 2.5 and 97.5 percentiles. (2013), Hyland and Sheldon (2013), Roth- Nebelsick et al. B: CO 2 proxy record from Royer (2014), with additional data from Badger et al. A: Likely minimum global mean surface temperature, calculated from the benthic foraminifera d 18 O compilation of Zachos et al. Proxy record of Cenozoic CO 2 and temperature. To better understand the climate forcings and feedbacks responsible for this amplification. Our results support the case that long-term climate sensitivity toД¬O2 in the past was sometimes high, even during largely ice-free periods, highlighting the need Present at Napartulik during the middle Eocene were maintained under CO2 concentrations These estimates represent the firstДirect constraints on CO2 for a High Arctic forest and suggest that the temperate conditions Site median of 424 ppm (351вЂ“523 ppm at 95% confidence). Individual reconstructions vary between 392 ppm and 474 ppm, with a Metasequoia (dawn redwood) leaves to reconstruct atmospheric CO2 from six fossil forest horizonsДЄt Napartulik. Here we apply a new plant gas-exchange model to Napartulik or any other polar forest site. Despite this wealth of paleontological and paleoclimatologicalДata, there are currently no direct constraints on atmospheric CO2 levels for

An abundance of dataДЇrom Napartulik suggests mean annual temperatures at least 30 вЊ warmer than today andДЄtmospheric water loads 2Г— current levels. Polar forest sites, Napartulik, crops out of middle Eocene (47.9вЂ“37.8 Ma) sediments onД®astern Axel Heiberg Island, Nunavut, Canada (~78В°N paleolatitude). One of the most well-known and stunningly preserved System dynamics in a largely ice-free world. Fossils from Paleogene High Arctic deposits provide some of the clearest evidence for greenhouseД¬limates in the past and offer the potential to improve our understanding of Earth

Metasequoia 4 mech parts