An astonishing new study suggests that cow farts may play a much bigger role in the warming of our planet than we thought possible.
A new NASA-sponsored study shows that global methane emissions produced by livestock are 11% higher than estimates made last decade. Because methane is a particularly nasty greenhouse gas, the new finding means it’s going to be even tougher to combat climate change than we realized.
Natural byproduct of the cow is methane as its gut microbes breakdown the tough vegetation it eats. Methane traps the sun’s heat and warming our planet. CO2 is the biggest culprit in this effect, methane is far more effective than CO2 when it comes to keeping heat.
We’ve known for quite some time that greenhouse gases produced by cattle, sheep, and pigs are a significant contributor to global warming, but the new research, published in Carbon Balance and Management, shows it’s worse than we thought. Revised figures of methane produced by livestock in 2011 were higher than estimates made in 2006 by the Intergovernmental Panel on Climate Change (IPCC) a now out-of-date estimate.
In a project sponsored by the U.S. National Aeronautics and Space Administration’s (NASA) Carbon Monitoring System research initiative, researchers from the Joint Global Change Research Institute (JGCRI) found that global livestock methane (CH4) emissions for 2011 are 11% higher than the estimates based on guidelines provided by the Intergovernmental Panel on Climate Change (IPCC) in 2006 – reads a statement from Biomed Central. This encompasses an 8.4% increase in CH4 from enteric fermentation (digestion) in dairy cows and other cattle and a 36.7% increase in manure management CH4 compared to IPCC-based estimates. Revised manure management CH4 emissions estimates for 2011 in the US from this study were 71.8% higher than IPPC-based estimates.
There are approximately 1.5 billion cows on the planet, each and every one of them expelling upwards of 30 to 50 gallons of methane each day. We typically think of farts as being the culprit, but belches are actually the primary source of cattle-produced methane, accounting for 95 percent of the problematic greenhouse gas.
Argentina scientists are now attaching backpacks to collect cow farts.
Methane is about 30 times more efficient at trapping the Sun’s radiative heat than carbon dioxide over a timescale of about a century. There may be more CO2 in the atmosphere than methane, but by unit, it’s the more destructive greenhouse gas. Both NASA’s Carbon Monitoring System research initiative and the Joint Global Change Research Institute (JGCRI) contributed to the study.
The estimates are 15% larger than global estimates provided by the U.S. Environmental Protection Agency (EPA), only quite smaller than estimates provided by the EPA for the US, 4% larger than EDGAR (Emissions Database for Global Atmospheric Research) global estimates, 3% larger than EDGAR estimates for US and 54% larger than EDGAR estimates for the state of California. Both the EPA and EDGAR use IPCC 2006 default information which may have contributed to their under estimations.
Among global regions, there was notable variability in trends in estimated emissions over recent decades – said Ghassem Asrar, Director of JGCRI and a co-author of the new study. For example, we found that total livestock methane emissions have increased the most in rapidly developing regions of Asia, Latin America, and Africa…We found the largest increases in annual emissions to be over the northern tropics, followed by the southern tropics.
It’s not immediately clear how, or even if, these revised figures will impact livestock production or public policy, but at the individual level, it suggests we should cut back on our consumption of meat and dairy. The privilege we have over these animals, it would appear, now comes at a hefty price.