Renewed growth of atmospheric methane

@article{Rigby2008RenewedGO,
  title={Renewed growth of atmospheric methane},
  author={Matthew L. Rigby and Ronald G. Prinn and P. J. Fraser and P. G. Simmonds and R. L. Langenfelds and J. Huang and Derek Martin Cunnold and L. Paul Steele and Paul B. Krummel and Ray F. Weiss and Simon J. O'Doherty and Peter K. Salameh and H. J. Ray Wang and Christina M. Harth and Jens M{\"u}hle and L. W. Porter},
  journal={Geophysical Research Letters},
  year={2008},
  volume={35}
}
Following almost a decade with little change in global atmospheric methane mole fraction, we present measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) networks that show renewed growth starting near the beginning of 2007. Remarkably, a similar growth rate is found at all monitoring locations from this time until the latest measurements. We use these data, along with an inverse method… 
Role of atmospheric oxidation in recent methane growth
TLDR
It is found that it is not possible to implicate, with a high degree of confidence, rapid global CH4 emissions changes as the primary driver of recent trends when the authors' inferred OH trends and these uncertainties are considered.
Rising atmospheric methane: 2007–2014 growth and isotopic shift
From 2007 to 2013, the globally averaged mole fraction of methane in the atmosphere increased by 5.7 ± 1.2 ppb yr−1. Simultaneously, δ13CCH4 (a measure of the 13C/12C isotope ratio in methane) has
The Drivers of Atmospheric Methane Fluctuations over the Last Three Decades
Understanding the processes behind the observed methane fluctuations over the last three decades is crucial for reliable projections of future levels of atmospheric methane, the second most important
A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4
TLDR
The atmospheric methane level has resumed its increase after a plateau between 1999 and 2006, and a box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the plateau.
Analysis of recent atmospheric methane trends using models and observations
Over the past two decades the growth rate of methane has shown large variability on multi-year timescales, the reasons for which are not well understood. The JULES land surface model, TOMCAT 3-D
Three decades of global methane sources and sinks
Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces
Historical and Contemporary Global Methane Cycling
Methane (CH4) has been studied as an atmospheric constituent for more than 200 years. However, the first modern measurements of atmospheric CH4 concentration were made by using the infrared
Ambiguity in the causes for decadal trends in atmospheric methane and hydroxyl
TLDR
It is concluded that the current surface observing system does not allow unambiguous attribution of the decadal trends in methane without robust constraints on OH variability, which currently rely purely on methyl chloroform data and its uncertain emissions estimates.
Growth Rate, Seasonal, Synoptic, Diurnal Variations and Budget of Methane in the Lower Atmosphere
We have used an AGCM (atmospheric general circulation model)-based Chemistry Transport Model (ACTM) for the simulation of methane (CH4) in the height range of earth’s surface to about 90 km. The
Non-CO 2 Greenhouse Gases
In the past decades, accurate and precise atmospheric measurements of radiatively active gases have been crucial in revealing the rapid and unceasing growth of their global concentrations that has
...
...

References

SHOWING 1-10 OF 29 REFERENCES
Contribution of anthropogenic and natural sources to atmospheric methane variability
TLDR
The results indicate that wetland emissions dominated the inter-annual variability of methane sources, whereas fire emissions played a smaller role, except during the 1997–1998 El Niño event.
Evidence for variability of atmospheric hydroxyl radicals over the past quarter century
The hydroxyl free radical (OH) is the major oxidizing chemical in the atmosphere, destroying about 3.7 petagrams (Pg) of trace gases each year, including many gases involved in ozone depletion, the
Atmospheric methane levels off: Temporary pause or a new steady‐state?
The globally‐averaged atmospheric methane abundance determined from an extensive network of surface air sampling sites was constant at ∼1751 ppb from 1999 through 2002. Assuming that the methane
The growth rate and distribution of atmospheric methane
Methane was measured in air samples collected approximately weekly from a globally distributed network of sites from 1983 to 1992. Sites range in latitude from 90°S to 82°N. All samples were analyzed
On the role of hydroxyl radicals in the self-cleansing capacity of the troposphere
Thousands of megatons natural and anthropogenic gases are released and subsequently removed from the troposphere each year. Photochemical reactions, initiated by hydroxyl (OH) radicals, oxidise most
Measurements of an anomalous global methane increase during 1998
Measurements of atmospheric methane from a globally distributed network of air sampling sites indicate that the globally averaged CH4 growth rate increased from an average of 3.9 ppb yr−1 during
In situ chloroform measurements at Advanced Global Atmospheric Gases Experiment atmospheric research stations from 1994 to 1998
Measurements of atmospheric chloroform (CHCl3) by in situ gas chromatography using electron capture detection are reported from the Advanced Global Atmospheric Gases Experiment (AGAGE) network of
A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE
We describe in detail the instrumentation and calibrations used in the Atmospheric Lifetime Experiment (ALE), the Global Atmospheric Gases Experiment (GAGE), and the Advanced Global Atmospheric Gases
Atmospheric modeling of high‐ and low‐frequency methane observations: Importance of interannually varying transport
[1] We compare modeled and observed atmospheric methane (CH4) between 1996 and 2001, focusing on the role of interannually varying (IAV) transport. The comparison uses observations taken at 13
...
...