This study quantitatively estimates the spatial distribution of anthropogenic methane sources in the United States by combining comprehensive atmospheric methane observations, extensive spatial datasets, and a high-resolution atmospheric transport model. Results show that current inventories from the US Environmental Protection Agency (EPA) and the Emissions Database for Global Atmospheric Rese...

The present study was conducted to evaluate in vivo the role of rumen ciliate protozoa with respect to the methane-suppressing effect of coconut oil. Three sheep were subjected to a 2 x 2 factorial design comprising two types of dietary lipids (50 g x kg(-1) coconut oil vs. 50 g x kg(-1) rumen-protected fat) and defaunation treatment (with vs. without). Due to the defaunation treatment, which r...

The emission of methane and the higher hydrocarbons is observed in both mid-ocean ridge and subduction-related hydrothermal systems. It has been recently reported that methane emanating from an extensional ultramafichydrothermal system originates from the abiogenic reduction of (mantle) CO2 (1). The same process is also known to occur in subaerial subduction-related systems (2). These findings ...

The costs of greenhouse gas emission reduction with abatement of carbon dioxide, methane, and nitrous oxide are investigated using the FUND model. The central policy scenario keeps anthropogenic radiative forcing below 4.5 Wm. If CO 2 emission reduction were the only possibility to meet this target, the net present value of consumption losses would be $45 trillion; with abatement of the other g...

Methane is a climatologically important greenhouse gas, which plays a key role in regulating water vapour in the stratosphere and hydroxyl radicals in the troposphere. Recent findings that vegetation emits methane have stimulated efforts to ascertain the impact of this source on the global budget. In this work, we present the re-5 sults of high frequency (ca. 1 min −1) methane measurements cond...

The attenuation of methane and four chlorofluorocarbons was investigated in a dynamic methane and oxygen counter-gradient system simulating a landfill soil cover. Soil was sampled at Skellingsted Landfill, Denmark. The soil columns showed a high capacity of methane oxidation with oxidation rates of 210 g m(-2) d(-1) corresponding to a removal efficiency of 81%. CFC-11 and to a lesser extent als...

Methane is the second most important greenhouse gas contributing to climate warming. The open ocean is a minor source of methane to the atmosphere. We report intense methane emissions from the near-shore southern region of the North Sea characterized by the presence of extensive areas with gassy sediments. The average flux intensities (~130 μmol m(-2) d(-1)) are one order of magnitude higher th...

[1] Methane (CH4) represents a major product of organic matter decomposition in lakes. Once produced in the sediments, CH4 can be either oxidized or emitted as a greenhouse gas to the atmosphere. Lakes represent an important source of atmospheric CH4, but the relative magnitudes of the internal pathways that lead to CH4 emissions are not yet clear. We quantified internal cycling and methane emi...

The recent growth in production and utilization of natural gas offers potential climate benefits, but those benefits depend on lifecycle emissions of methane, the primary component of natural gas and a potent greenhouse gas. This study estimates methane emissions from the transmission and storage (T&S) sector of the United States natural gas industry using new data collected during 2012, includ...

Cobalt chromite (CoCr2O4) with normal spinel structure, shows catalytic activity for oxidation of unburned methane in the natural gas vehilcles (NGV). In this study, CoCr2O4 nanoparticles were synthesized through a conventional co-precipitation technique and investigated for the catalytic combustion of methane. Cobalt nitrate hexahydrate,...