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The atmospheric CH4 increase from ∼0.7 to 1.68 p.p.m.v. over about the past 300 years which has been documented from analysis of air trapped in ice cores1-4 and from tropospheric measurements (see ref. 5 for example) is attributed to anthropogenic modifica ...
The disturbed stratigraphy of the ice in the lowest 10% of the Greenland GRIP ice core prevents direct access to climatic information older than 110 kyr. This is especially regretful since this period covers the previous interglacial corresponding to marin ...
The oxidative capacity of past atmospheres is highly uncertain. We present here a new climate-biosphere-chemistry modeling framework to determine oxidant levels in the present and past troposphere. We use the GEOS-Chem chemical transport model driven by me ...
This article presents a state-of-the-art of atmospheric methane reconstruction based on ice-core studies. Starting with a biogeochemical overview of the methane cycle, it explains the processes of gas diffusion in firn and trapping in ice. It presents and ...
Using new and previously published CO2 data from the EPICA Dome C ice core (EDC), we reconstruct a new high-resolution record of atmospheric CO2 during Marine Isotope Stage (MIS) 6 (190 to 135 ka) the penultimate glacial period. Similar to the last glacial ...
Gases trapped in polar ice provide our most direct record of the changes in greenhouse gas levels during the past 150,000 years. The best documented trace-gas records are for CO2 and CH4. The measurements corresponding to the industrial period document the ...
American Association for the Advancement of Science (AAAS)2008
Ease of worldwide travel provides increased opportunities for organisms not only to colonize new environments but also to encounter related but diverged populations. Such events of reconnection and secondary contact of previously isolated populations are w ...
The Antarctic Vostok ice core provided compelling evidence of the nature of climate, and of climate feedbacks, over the past 420,000 years. Marine records suggest that the amplitude of climate variability was smaller before that time, but such records are ...
Recent studies show that soil eukaryotic diversity is immense and dominated by micro-organisms. However, it is unclear to what extent the processes that shape the distribution of diversity in plants and animals also apply to micro-organisms. Major diversif ...
The suggestion of climatic instability during the last interglacial period (Eem), based on the bottom 10% of the Greenland Ice core Project (GRIP) isotopic profile, has been questioned because the bottom record from the neighboring Greenland Ice Sheet Proj ...
