Tag Archive for: Methane

Cattle Drugs Could Fuel Climate Change, Study Suggests

Author:

Dosing farm animals with antibiotics increases greenhouse gas emissions from cow dung, research suggests.

Scientists say the drugs boost methane production in cowpats – apparently by favouring antibiotic-resistant, methane-producing organisms in the gut.

Antibiotics also change the microbes which inhabit dung beetles, although apparently with no adverse effects.

The researchers say it’s proof that antibiotic use on farms has unintended, cascading effects on the environment.

For the new paper, in Proceedings of the Royal Society B, researchers followed the trail of antibiotics in cattle and discovered, perhaps unsurprisingly, that said trail did not stop at the cow’s rear end.

The antibiotics changed the microbes in the digestive system of dung beetles, which are vital for cycling carbon and improving soil. The beetles, though, did not appear to be damaged.

By contrast, clear harm was measured in the antibiotic-contaminated cowpats themselves, which produced 1.8 times more methane – a powerful greenhouse gas.

Not a bombshell

This was a surprise, as previous studies have found little or no impact on the dung.

One of the authors, Tobin Hammer from the University of Colorado, told BBC News that some key research questions remained unanswered.

KEEP READING ON BBC

We can’t fight climate change without tackling agriculture emissions: Bob McDonald

Author: Bob McDonald

When it comes to air pollution and greenhouse gas emissions, we generally think of the usual suspects: fossil fuel-powered electrical generating stations, vehicles and industry. But, in fact, agriculture represents roughly one-third of global greenhouse gas emissions, as well as a significant amount of air pollution, and that means we need to make significant changes to the way we farm to help curb global warming and clean up the air we breathe.

Two reports released this week say that improvements in agricultural practices based on current technology will not be enough to bring those emissions down.

The first report, in the journal Global Change Biology, was from an international team that focused on emissions from gases other than carbon dioxide. Carbon dioxide is absorbed from the atmosphere when crops are planted and released after harvest, so in that sense, agriculture is carbon neutral.

Instead, the researchers looked at methane, which comes from livestock and decaying organic matter, and nitrous oxide, which is produced by fertilizer. Both are significant greenhouse gases. The report states that current mitigation plans would only reduce emissions by 20 to 40 per cent, not enough to meet the targets set by the Paris climate accord.

A second report in Geophysical Research Letters shows that agricultural practices in the United States are responsible for more particulate matter in the atmosphere than all other industrial sources. The use of nitrogen fertilizers, techniques used for soil preparation, decaying organic matter and livestock activity produce tiny airborne particles that combine with other air pollution to create aerosols that contribute to a variety of respiratory diseases and public health problems.

Reducing emissions while maintaining production

The agriculture industry faces the difficult challenge of reducing emissions without compromising food production, because more and more mouths to feed are being added to the planet every day.

KEEP READING ON CBC NEWS

Cowspiracy: Revelation or Cheap Trick?

Are environmentalists afraid of stepping in cow dung? The documentary film Cowspiracy contends that large environmental groups are turning a blind eye to the harmful effects cattle have on ecosystems and human health. Environmentalists bristle at the charge and point to work promoting vegan and vegetarian diets and campaigns against factory farms and other excesses of the animal agriculture industry. The film, which was backed by Leonardo DiCaprio, presents “a sensationalist conspiracy where none exists,” according to Greenpeace executive Robin Oakley.

However, a growing number of environmentalists are praising cows and claim they can be climate healers rather than the villains they are often made out to be. They contend that a cow’s methane-rich burps can be offset if cattle grazing patterns are carefully managed. The result, they say, can be pretty landscapes and healthy soil that stores both carbon and water. Is that just spin from cattle ranchers? Does Cowspiracy use green groups as a foil to make a sensational film to generate buzz? A conversation about the future of an American icon in the age of climate disruption.

This podcast features:

Kip Andersen, Founder, AUM Films and Media
Nicolette Hahn Niman, Author, Defending Beef
Jonathan Kaplan, Director, Food and Agriculture Program, Natural Resources Defense Council

This program was recorded in front of a live audience at the Commonwealth Club of California on April 12, 2016

LISTEN TO THE PODCAST ON CLIMATE ONE

Could Eating Less Meat INCREASE Greenhouse Gas Emissions?

Author: Kathy Voth

OK – We’ve all heard it. Eating less meat is better for the planet. Why? Well, there’s research showing that 1) meat production has a big carbon footprint; and 2) ruminants emit lots of methane in farts, burps and manure and this is a problem because methane is an even more potent greenhouse gas than carbon dioxide. But like most things in life, this is a complex issue, and the results of recent research indicate that at least in one region of the world, eating less meat might increase global greenhouse gas emissions.

According to research by University researchers at Scotland’s Rural College and the Brazilian Agricultural Research Corporation, reducing beef production in the Brazilian Cerrado could increase global greenhouse gas emissions. Lead researcher Rafael Silva explains the reasons this way:

“Much of Brazil’s grassland is in poor condition, leading to low beef productivity and high greenhouse gas emissions from cattle. However, increasing demand for meat provides an incentive for farmers to recover degraded pastures. This would boost the amount of carbon stored in the soil and increase cattle productivity. It would require less land for grazing and reduce deforestation, potentially lowering emissions.”

The findings published in the January issue of the journal Nature Climate Change indicate that if demand for beef is 30 per cent higher by 2030 compared with current estimates, net emissions would decrease by 10 per cent. Reducing demand by 30 per cent would lead to 9 per cent higher emissions, provided the deforestation rates are not altered by a higher demand.

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Born to Rewild

Author: Eli Kintisch

In April 2011, Nikita Zimov climbed into a heavy duty truck with six elk in the back and set out from Novosibirsk, a major city in southern Siberia, on a 4000-kilometer trek to the edge of the world. Time was not on his side. He had to reach the Arctic town of Cher-sky, where he and his father, Sergey, run a hardscrabble research outpost called the Northeast Science Station (NESS), before the spring thaw melted the frozen rivers that serve as winter roads in northern Siberia. White wooden crosses marked spots along the winding road where unlucky drivers had perished. Two weeks into his journey, just 40 kilometers from home, Zimov hit a snowbank—his brakes were shot—and the truck tipped over. Unscathed, he phoned his father and spent the next 4 hours, cold and exhausted, leaning against a flimsy tarp hat covered the truck’s roof to keep the elk, also uninjured, from bolting. “I was miserable,” he says. “Almost literally insane.”

Sergey swooped in to rescue Nikita and the elk, and the animals finally reached their destination: Pleistocene Park, a 14,000-hectare reserve near Chersky founded by the elder Zimov 19 years ago. It’s a grand experiment to test whether large herbivores—elk, moose, reindeer, horses, and bison—can, simply by grazing, bring back a grass-dominated ecosystem called the mammoth steppe. That biome dominated the northern reaches of Eurasia and North America for 2 million years, until the end of the last glacial period some 13,000 years ago, when  the landscape turned to mossy tundra and sparsely forested taiga.

If the Zimovs are right, a brighter future for the entire globe may hinge on the experiment’s success. A decade ago, Sergey and colleagues estimated that permafrost encircling the upper Northern Hemisphere contains a whopping 1 trillion tons of carbon—twice earlier estimates—and that this vast pool may be on the brink of leaking into the atmosphere. The finding was a clarion call to climate scientists to take the arctic carbon threat seriously. “This is the most dangerous territory in the world in terms of climate change,” Zimov declares.

Keep Reading in Science Magazine

Ruminants and methane: Not the fault of the animals

Author: Alan Broughton

Cattle and sheep are blamed for contributing to greenhouse gases, belching out methane, and farmers in the future are likely to be taxed because of it.

The recent Green Left Weekly climate change liftout [issue #1078] calls for a drastic reduction in sheep and cattle numbers. There is a TV advertisement, urging people to “go vego to save the planet”. This is a gross misunderstanding of the ruminant carbon cycle.

Ruminants have always emitted methane; it is not something new. Huge herds of wild buffalo, cattle, goats, sheep, deer, cameloids and wildebeest have grazed the grasslands of the world for millions of years. The American prairies once supported greater numbers of bison than they now do cattle, despite the intensive corn and soy production that feeds them.

Methane emissions from wild ruminants was never a problem because nature does not permit waste — the methane was used as food for methanotrophic bacteria in the soil and neutralised. It was never a problem until agricultural practices started destroying these methanotrophic bacteria, which are very sensitive to chemical fertilisers and herbicides. These bacteria reactivate in biologically managed soil.

However, methane is not the whole picture. When the contribution of livestock to soil carbon sequestration is taken into account it is easy to see that ruminants do not increase greenhouse gases if they are managed well.

Grassland soils are the greatest sequesters of carbon — greater than forests. In the top one metre of soils in temperate grasslands there is an average of 236 tonnes of carbon, compared to 96 in temperate forest soils and 80 in cropland.

Keep Reading in Green Left Weekly

Soil Carbon – Can it Save Agriculture’s Bacon?

Author: Dr. Christine Jones

The number of farmers in Australia has fallen 30 per cent in the last 20 years, with more than 10,000 farming families leaving the agricultural sector in the last five years alone. This decline is ongoing. There is also a reluctance on the part of young people to return to the land, indicative of the poor image and low income-earning potential of current farming practices.

Agricultural debt in Australia has increased from just over $10 billion in 1994 to close to $60 billion in 2009 (Fig.1). The increased debt is not linked to interest rates, which have generally declined over the same period (Burgess 2010).


Fig. 1. Increase in agricultural debt (AUD millions)
1994-2009 vs interest rates (%pa)

The financial viability of the agricultural sector, as well as the health and social wellbeing of individuals, families and businesses in both rural and urban communities, is inexorably linked to the functioning of the land.

There is widespread agreement that the integrity and function of soils, vegetation and waterways in many parts of the Australian landscape have become seriously impaired, resulting in reduced resilience in the face of increasingly challenging climate variability.

Agriculture is the sector most strongly impacted by these changes. It is also the sector with the greatest potential for fundamental redesign.

The most meaningful indicator for the health of the land, and the long-term wealth of a nation, is whether soil is being formed or lost. If soil is being lost, so too is the economic and ecological foundation on which production and conservation are based.

Keep Reading on Permaculture Research Institute

Ruminants and Methane

Author: Dr. Christine Jones

Wetlands, rivers, oceans, lakes, plants, decaying vegetation (especially in moist environments such as rain forests) – and a wide variety of creatures great and small – from termites to whales, have been producing methane for millions of years. The rumen, for example, evolved as an efficient way of digesting plant material around 90 million years ago.

Ruminants including buffalo, goats, wild sheep, camels, giraffes, reindeer, caribou, antelopes and bison existed in greater numbers prior to the Industrial Revolution than are present today. There would have been an overwhelming accumulation of methane in the atmosphere had not sources and sinks been able to cancel each other over past millennia.

Although most methane is inactivated by the hydroxyl (OH) free radical in the atmosphere,another source of inactivation is oxidization in biologically active soils. Aerobic soils are net sinks for methane, due to the presence of methanotrophic bacteria, which utilize methane as their sole energy source. Methanotrophs have the opposite function to methanogens, which bind free hydrogen atoms to carbon to reduce acidosis in the rumen. Recent research has found that biologically active soils can oxidize the methane emitted by cattle carried at low stocking rates. The highest methane oxidation rate recorded in soil to date has been 13.7mg/m2/day which, over one hectare, equates to the absorption of the methane produced by approximately one livestock unit (LSU).

In Australia, it has been widely promoted that livestock are a significant contributor to atmospheric methane and that global methane levels are rising. There is no evidence, however, to suggest that methane emissions from ruminant sources are increasing. Indeed, it would seem there has been no clear trend to changes in global methane levels, from any source, over recent decades.

Keep Reading in The Natural Farmer