Methane Gas Emissions

Methane CH4 is a greenhouse gas that the International Panel on
Climate Change estimates is between 21-23 times the potency of carbon
dioxide. Methane is produced by the digestion process of cattle, from
wetlands, termites, rice growing, fossil fuel use, landfill methane
gas and industrial processes.According to the CSIRO the gas
concentrations in the atmosphere have approximately doubled since the
industrial revolution, rising from 700ppb to ~1795 in 2010. Over the
last decade however methane levels in the atmosphere have been
relatively stable. Between 2007-2009 there was a small spike in
methane levels, but following that the growth rate returned to
approximately zero.Sources of methane gas emissions- Methane is
emitted from both natural sources and human activities
- Natural
emissions are dominated by anaerobic breakdown of organic matter in
wetlands
- Human activities account for more than 60% of global
emissions as per below:Source - % total Anthropogenic emissions
Fossil
fuels - 25%
Livestock - 25%
Rice cropping - 20%
Landfill methane -
20%
Biomass burning - 10%Causes of increase in methane gasA report by
CSIRO and other organisations that was published in 2010 in ECOS found
that the rise in methane emission levels in the atmosphere was caused
by the release of this gas previously stored in wetlands in the
arctic. The warmer summers of 2006 and 2007 as well as the wetter
conditions in the tropics contributed to the release of this gas from
the arctic wetlands. The report suggests that with climate change and
unpredicted weather conditions that there is a risk of continued spike
in atmospheric methane being released from arctic wetlands.Cows
methane gasThe most commonly discussed contributor to atmospheric
methane emissions is the one from cows. However as noted above cows
the gas contributes 25% of anthropogenic emissions globally, the same
as fossil fuels and just slightly more than rice growing and
landfill.Reducing emissions from cattleThe Australian cattle industry
is focused on looking at how to reduce this gas emissions from
ruminant (cattle and sheep) digestion. Meat and Livestock Australia in
partnership with the federal government has a $28 million project
underway with 18 different research projects under the banner of
Reducing Emissions from Livestock Research Program (RELRP). Under this
program research bodies from across the country are looking at how to
more effectively measure methane, such as with methane detector.
Researchers are also investigating whether there are particular
animals that naturally produce less methane gas and if so, if this can
be selectively bred for.Another area of focus under the RELRP is
whether different feeds can have an impact on reducing the gas release
of cows. One of the projects funded under RELRP is being undertaken by
Dr Ed Charmley from the CSIRO. Dr Charmley has recently reported some
positive findings with feeding cattle a Mexican fodder tree, with
methane gas detector showing that it leads to cows methane gas being
20% lower than cows that don't eat the Mexican fodder tree.