Nearly 75% of nitrous oxide and 80% of methane emissions can be traced to the agricultural sector. link  Today, the majority of American farmland is dominated by industrial agriculture, the system of chemically intensive food production developed in the decades after World War II, featuring enormous single-crop farms and animal production facilities. Back then, industrial agriculture was hailed as a technological triumph that would enable a skyrocketing world population to feed itself. Today, a growing chorus of agricultural experts, including farmers as well as scientists and policymakers, sees industrial agriculture as a dead end, a mistaken application to living systems of approaches better suited for making jet fighters and refrigerators. The impacts of industrial agriculture on the environment, public health, and rural communities make it an unsustainable way to grow our food over the long term. And better, science-based methods are available. link



  • Agriculture – general
  • Factory farming and  greenhouse gases
  • Meat consumption globally
  • Grass-fed debate
  • How to reduce emissions
 Agriculture – general

Large-scale  meat production also has serious implications for the world’s climate. Animal waste releases methane and nitrous oxide, greenhouse gases that are 25 and 300 times more potent than carbon dioxide, respectively. Global meat production and consumption have increased rapidly in recent decades, with harmful effects on the environment and public health as well as on the economy, according to research done by Worldwatch Institute’s Nourishing the Planet project for Vital Signs Online. Worldwide meat production has tripled over the last four decades and increased 20% in just the last 10 years. Meanwhile, industrial countries are consuming growing amounts of meat, nearly double the quantity in developing countries. link

July 2018: Meat and dairy industries surpass oil industry as world’s biggest polluters. If the agricultural industry continues down its current path, the authors of a new report warned that the livestock sector could be responsible for 80% of the allowable greenhouse gas budget by 2050. The report adds to a growing body of evidence for the harm meat and dairy consumption can cause to the planet. link

May 2018: New analysis of damage farming does to planet. Avoiding meat and dairy products is the single biggest way to reduce the environmental impact on the planet. New research shows that without meat and dairy consumption, global farmland use could be reduced by more than 75%. The analysis shows that while meat and dairy provide just 18% of calories and 37% of protein, it uses the vast majority, 83%, of farmland and produces 60% of agriculture’s greenhouse gas emissions. link

May 30 2018: Livestock companies not reporting emissions. Three out of four (72%) of the world’s biggest meat and fish companies provided little or no evidence to show that they were measuring or reporting their emissions, despite the fact that livestock production represents 14.5% of all greenhouse gas emissions. By failing to properly report their climate emissions, meat and fish companies may be “putting the implementation of the Paris agreement in jeopardy.” link

January 2017: Agriculture begins to tackle its role in climate change. After years of being off the table in climate talks, agriculture is now being considered widely by countries trying to reach their Paris emissions cuts pledges. “Agriculture has really lagged, said Craig Hanson, director of the food, forests and water program at the World Resources Institute. ”Considering it contributes 13% of greenhouse gas emissions, and 24% of net emissions with land-use change, it’s surprising it’s taken so long . . .but it’s finally happening,” he said – however unevenly. link

September 2017: Factory farming is killing the planet – link

July 2015: Agriculture may be emitting 40% more of one greenhouse gas than previously thought – link

December 2015: Earth has lost a third of arable land in past 40 years, scientists say. The continual ploughing of fields, combined with heavy use of fertilizers, has degraded soils across the world, research found, with erosion occurring at a pace of up to 100 times greater than the rate of soil formation. It takes around 500 years for just 2.5cm of topsoil to be created amid unimpeded ecological changes. This has potentially disastrous consequences as global demand for food soars, scientists have warned. New research has calculated that nearly 33% of the world’s adequate or high-quality food-producing land has been lost at a rate that far outstrips the pace of natural processes to replace diminished soil. link

July 2011: Between 1850 and 1970 agriculture contributed most CO2. Over the past 150 years, between 50% and 80% of organic carbon in the topsoil has vanished into the air, and seven tons of carbon-banking topsoil have been lost for every ton of grain produced. When we consider our CO2 predicament, we tend to fault our love affair with the car and the fruits of industry. But the greater culprit has been agriculture: since about 1850, twice as much atmospheric CO2 has derived from farming practices as from the burning of fossil fuels (the roles crossed around 1970). The catalyst for reducing CO2 and restoring soil function and fertility, they say, is bringing back the roving, grazing animals that used to wander the world’s grasslands. The natural processes that take place in the digestive system and under the hooves of ruminants might be the key to turning deserts back into grasslands and reversing climate change. link 

Factory farming and  greenhouse gases

More than half of methane released each year comes from human activities, notably farming. (July 2007) The Journal of Animal Science says that ruminant animals produce between 250 and 500 liters of methane gas every day. The combined environmental effect of the world’s livestock is enormous. There are around 1.5 billion cattle on our planet – more than double the number 30 years ago. Normally a cow’s stomach is pretty inefficient – 80% of food ingested comes out as waste or methane. There are also over a billion sheep and some 800 million goats. Animal agriculture produces more than 100 million tons of methane a year and many organizations urge a vegetarian diet to help avert climate catastrophe. Changing the ruminants’ diets is another approach. A trial in Scotland on lamb recently obtained a 70% decrease in methane formation, while in New Zealand, where agriculture accounts for almost 50% of the country’s greenhouse gas emissions, scientists are working on reducing methane by getting rid of the microbes in animals’ stomachs that produce methane. link

November 2017:  Getting a better handle on methane emissions from livestock. Cattle, swine and poultry contribute a hefty portion to the average American’s diet, but raising all this livestock comes at a cost to the environment.  Just how much methane animals release, however, is the subject of debate According to the U.S. EPA, the livestock industry is the second-biggest methane emitter in the U.S. Current estimates of total livestock methane emissions may rely on outdated emission factors and do not fully consider feed intake and differences in animal diets, or the facilities used to store manure. These data gaps lead to large uncertainties in methane emission figures. link

Grazing can fight desertification and reverse climate change
Allan Savory TED talk on holistic farming to sequester carbon – link
Response from George Monbiot (August 2014)  “(Savory’s) statements are not supported by empirical evidence and experimental work, and that in crucial respects his techniques do more harm than good.” link

October 2017: The last argument for farming animals has collapsed. The answer, we are told, is to keep livestock outdoors: eat free-range beef or lamb, not battery pork. But all this does is to swap one disaster – mass cruelty – for another: mass destruction. Almost all forms of animal farming cause environmental damage, but none more so than keeping them outdoors. The reason is inefficiency. Grazing is not just slightly inefficient, it is stupendously wasteful. Roughly twice as much of the world’s surface is used for grazing as for growing crops, yet animals fed entirely on pasture produce just one gram out of 81 grams of protein consumed per person per day. link

April 2009: Which meat harms our planet the least? As a general rule, red meat (beef, lamb, goat, and bison) are the worst offenders.  link

November 2013: Emissions of methane in U.S. exceed estimates. Cattle may be a bigger problem than US government thought. The nearly 90 million cattle in US feedlots are the country’s largest source of methane from anthropogenic (human-caused) emissions according to the EPA. A new report published by Harvard University scientists estimate they may release 50% more methane into the atmosphere than the government had estimated. The new report finds that ruminant animals generate twice as much methane as the EPA supposed. The report comes on the heels of a decision by the EPA to reduce its estimates – by 25 to 30% – of the atmospheric carbon released by the natural-gas industry.  link

The counter argument.
Don’t blame dairy cows for greenhouse gas emissions – new study
Eating less meat and dairy products won’t have major impact on global warming, expert argues. Read here

 Meat consumption globally

Over the past 50 years, global meat production has almost quadrupled from 78 million tonnes in 1963 to a current total of 308 million tonnes per year. In 2014, around 315 million tonnes of meat were produced worldwide. For 2015, the FAO forecasts an increase to 318.8 million tonnes. The IAASTD predicts that this trend will continue, especially because the growing urban middle classes in China and other emerging economies will adapt to the so-called western diet of people in North America and Europe with its burgers and steaks. On average, every person on Earth currently consumes 42.9 kilograms of meat per year. In the EU, meat consumption has stagnated recently; there is also a growing number of vegetarians and vegans. What’s more, they main type of meat consumed has switched from beef to poultry. The favourite meat of the average European however is pork. The Chinese also share this appetite for pork. Per capita, meat consumption in China has increased six-fold over the past 40 years. Since the population almost doubled to 1.3 billion people over the same period, global demand for meat. link

Fermentation process:
Enteric fermentation is fermentation that takes place in the digestive systems of animals. In particular, ruminant animals (cattle, buffalo, sheep, goats, and camels) have a large “fore-stomach,” or rumen, within which microbial fermentation breaks down food into soluble products that can be utilized by the animal. The microbial fermentation that occurs in the rumen enables ruminant animals to digest coarse plant material that monogastric animals cannot digest. Methane is produced in the rumen by bacteria as a by-product of the fermentation process. This CH4 is exhaled or belched by the animal and accounts for the majority of emissions from ruminants. Methane also is produced in the large intestines of ruminants and is expelled. There are a variety of factors that affect CH4 production in ruminant animals, such as: the physical and chemical characteristics of the feed, the feeding level and schedule, the use of feed additives to promote production efficiency, and the activity and health of the animal. It has also been suggested that there may be genetic factors that affect CH4 production. Of these factors, the feed characteristics and feed rate have the most influence. link

March 2016: Eat less meat to avoid dangerous global warming – link

 Grass-fed debate

October 2017: Eating grass-fed beef isn’t climate-friendly. Ruminants contribute 80% of total livestock emissions. To meet the growing demand for protein from grass-fed animals, a new report said, “we would have to massively expand grazing land into forest and intensify existing grassland through the use of nutrient inputs, which among other things, would cause devastating CO2 releases and increases in methane and nitrous oxide emissions,” both potent climate-warming gases. link

Is grass-fed beef worse for the environment than grain-fed beef?  link  
June 2017:
 Grass-fed beef tends to require more land and emit more GHGs than grain-fed beef – link

The debate is still open
. (February 2013)  Water consumption, methane gas emissions, the impacts of growing grain for feed, transportation impacts, air and water quality impacts from feed lots … the list goes on. Washington State University researcher Judith Capper found that feeding cattle grain on feed lots uses less land than feeding them only grass. It shortens the amount of time it takes to raise cattle to market weight, which means each cow requires less water and produces less methane. She also found that grain-fed cattle produce a third less methane than grass-fed because of how they digest the different feeds, a finding that is backed up by an Australian study. The studies, however, have been challenged – grass-fed cattle help sequester carbon in pasture, and that the impacts to water and air quality are worse on feed lots. The Environmental Working Group concludes, after a lifecycle analysis of beef and other meats, that grass fed beef is better for the environment. link  

 How to reduce emissions

May 2018: Feeding seaweed to cows could slash the amount of climate change-inducing methane emissions from their burps. Preliminary research has indicated a small amount of marine algae added to cattle food can reduce methane emissions from cattle gut microbes by as much as 99%. “Results are not final, but so far we are seeing substantial emission reductions,” said Professor Ermias Kebreab at the University of California, Davis. link

Insects as an alternative solution. People have been eating insects for centuries, and up to 80% of the world outside Europe and North America still rely on insects for some part of their diet, it says. “Insects are one important solution as they offer a rich source of protein, amino acids, fatty acids and micronutrients,” said Giulia Muir, an FAO expert on edible insects. link

September 2013: Better farming methods can reduce emissions by 30%link

(July 2008) Researchers in Argentina, which has more than 55 million cows, discovered methane from cows accounts for more than 30% of the country’s total greenhouse emissions. Guillermo Berra, a researcher at the National Institute of Agricultural Technology, said every cow produces between 800 to 1,000 litres of emissions every day. Scientists are now carrying out trials of new diets designed to improve cows’ digestion and hopefully reduce global warming. Silvia Valtorta, of the National Council of Scientific and Technical Investigations, said that by feeding cows clover and alfalfa instead of grain “you can reduce methane emissions by 25%”. link

December 2013: New survey shows cattle are the biggest source of greenhouse gases, accounting for more than three-quarters of all emissions from global livestock. link)  [Cows’ belching and farting is known as “enteric fermentation”] 

November 2009: Australian scientists are hoping to breed sheep that burp less as part of efforts to tackle climate change – about 16% of Australia’s greenhouse emissions come from agriculture and 90% of the methane that sheep and cattle and goats produce comes from the rumen, and that’s burped out. link

Eat kangaroo to ‘save the planet’… 
Kangaroos could be good for the planet. Kangaroos produce virtually no methane because their digestive systems are different. BBC
A sustainable quota of 15-20% of the 30-50 million kangaroos is harvested each year. 70% of kangaroo meat (high in protein and low in fat) is exported, mainly to W. Europe. It is produced only from free ranging wild animals and is not farmed. Objections to the harvesting, or culling, comes in a study from Sydney University – link