From NOT A LOT OF PEOPLE KNOW THAT
By Paul Homewood
I used to be despatched this text from two years in the past, and it’s related to the talk on agriculture’s affect on GHGs:
The best way the general public and the media understand animal agriculture’s environmental affect can, and will, change. New analysis from Oxford College and the College of California, Davis have not too long ago debunked a number of the most crucial and long-standing myths surrounding animal agriculture. However can this breakthrough overcome animal agriculture’s dangerous fame?
The present narrative about animal agriculture says that ruminant livestock animals (e.g., beef cattle, dairy cattle, and many others.) produce methane. Methane is a potent greenhouse fuel. Thus, animal agriculture is dangerous for the surroundings.
Throughout a keynote presentation for the Alltech ONE Digital Expertise, Dr. Frank Mitloehner, professor on the College of California, Davis and air high quality specialist, boldly proclaimed a path for animal agriculture to turn into climate-neutral.
Sure, “you heard me proper — climate-neutral,” mentioned Dr. Mitloehner. He mentioned he want to, “get us to a spot the place we’ve got the impacts of animal agriculture that aren’t detrimental to our local weather.”
3 myths about animal agriculture’s environmental affect debunked
Fable #1: Methane (the commonest greenhouse fuel, or GHG, in animal agriculture) acts similar to different GHGs within the surroundings.
Reality: The three major greenhouse gases, carbon dioxide, methane and nitrous oxide, all affect the surroundings in critically other ways, particularly because it pertains to their supply, life span within the environment and international warming potential.
Carbon dioxide and nitrous oxide are generally known as “inventory gases.” Inventory gases are long-lived gases and as soon as emitted will proceed to construct up within the environment. Carbon dioxide, for instance, has an estimated lifespan within the environment of 1,000 years, that means carbon dioxide emitted from the yr 1020 should still be within the environment at the moment. Methane, however, is a “circulate fuel.” Circulation gases are short-lived gases and are faraway from the environment at a extra speedy tempo. Methane’s lifespan within the environment is roughly 10 years. This implies a circulate fuel like methane would affect the surroundings for a length that’s practically 100 occasions shorter than the inventory fuel carbon dioxide.
What causes these gases within the first place? Carbon dioxide is created by the burning of fossil fuels. Fossil fuels are used because the vitality supply to energy most properties, automobiles and trade globally. Because the graph under depicts, Dr. Mitloehner refers to inventory gases like carbon dioxide as a “one-way avenue” as a result of they solely accumulate within the surroundings over time resulting from their lengthy lifespan.
Methane may be produced in quite a lot of strategies, however mostly, it’s produced by way of the rumination course of in beef and dairy livestock (i.e., belching). As a short-lived circulate fuel, “The one time that you just actually add new extra methane to the environment with the livestock herd is all through the primary 10 years of its existence or if you happen to improve your herd sizes,” defined Dr. Mitloehner. Methane ranges don’t improve if herd sizes stay fixed as a result of methane is being damaged down on the identical charge it’s being produced.
“What I’m saying right here under no circumstances (is) that methane doesn’t matter,” he continued. “Whereas that methane is within the environment, it’s heat-trapping, it’s a potent greenhouse fuel. However the query actually is, do our livestock herds add to extra methane, that means extra carbon within the environment, resulting in extra warming? And the reply to that query isn’t any. So long as we’ve got fixed herds and even reducing herds, we aren’t including extra methane, and therefore not extra warming. And what I simply mentioned to you is a complete change within the narrative round livestock.”
Alternatively, carbon dioxide is created from extracting fossil fuels which are hundreds of thousands of years outdated and are trapped below the Earth’s floor.
“These long-lived local weather pollution are solely emitted,” mentioned Dr. Mitloehner. “They’re put into the environment, however there’s no actual sink for it in a serious manner.”
This demonstrates that carbon dioxide and methane are very various kinds of gases (inventory versus circulate) and have very completely different lifespans within the surroundings (1,000 years versus 10 years), however what about their international warming potential?
.
Fable #2: The present methodology for assessing the worldwide warming potential (GWP100) of greenhouse gases correctly accounts for all essential variables.
Reality: The preliminary methodology for calculating GWP100 misrepresents the affect of short-lived circulate gases, like methane, on future warming. The brand new “GWP*” is an improved and extra consultant measurement.
The preliminary GWP100 measures produced by the Kyoto Protocol practically 30 years in the past marked a really constructive step for assessing international warming. The preliminary paperwork included many footnotes and caveats to account for variability and unknown values. “However the footnotes had been reduce off, and folks ran with (it),” mentioned Dr. Mitloehner. “And in my view, that was a really harmful scenario that has actually gotten animal agriculture into lots of hassle, really, fairly frankly.”
The present GWP100 measurement generates an over-assessment of methane’s contributions to international warming. At present, in brief, GWP100 measurements are all standardized to a billion tonnes of carbon dioxide equal. So, all non-carbon dioxide emissions are transformed by multiplying the quantity of the emissions of every fuel by its international warming potential over 100 years worth. Methane has a GWP100 worth of 28, that means it’s 28 occasions stronger than carbon dioxide within the environment.
Sadly, any such calculation utterly omits the truth that circulate gases, like methane, are destroyed after roughly 10 years and wouldn’t proceed for the complete 100-year length as described within the GWP100 method. Moreover, it underestimates the affect that inventory gases, like carbon dioxide, would have that persist within the surroundings for 1,000 years.
Dr. Mitloehner cited Dr. Myles Allen from Oxford College because the pioneer of a brand new calculation referred to as “GWP*.” The brand new GWP* calculation higher accounts for each fuel depth and fuel lifespan within the environment in its measurements of world warming. It is a new narrative to clarify international warming emissions and, Dr. Mitloehner mentioned, “you will notice it’s going to achieve momentum, and it’ll turn into the brand new actuality” quickly.
Fable #3: To maintain up with rising demand and international inhabitants development, the US has continued to extend its numbers of beef and dairy cattle, thus improve methane emissions.
Reality: The USA reached peak beef and dairy cattle numbers within the Nineteen Seventies and has lowered its variety of animals each decade since, leading to 50 million fewer cattle in complete.
Over the past half-century, the US has made super progress to enhance effectivity and improve productiveness whereas additionally decreasing complete beef and dairy cattle numbers. For instance, in 1950, the U.S. dairy cow herd peaked at 25 million cattle. At the moment, the dairy herd is roughly 9 million cows, but it’s producing 60% extra milk — that’s considerably extra milk with 14 million fewer cows!
Although cattle numbers have continued to extend in international locations reminiscent of India and China, this implies the US has not elevated methane output — thus not rising GHG contributions from livestock — during the last 5 a long time.
https://www.alltech.com/weblog/3-myths-debunked-animal-agricultures-real-impact-environment
This primary fantasy of the article actually goes to the guts of the problem. As Dr Mitloehner explains, the worldwide inventory of methane within the environment is not going to improve except herds improve around the globe. And even if you happen to cast off all cattle, the discount in methane ranges is simply ten years value.
There are after all different components not taken under consideration right here. If we do abolish all livestock, how can we substitute that meals? All varieties of meals manufacturing, whether or not arable or not, contain the emission of GHGs, not least in the usage of fertilisers, which might inevitably improve with out the provision of manure.
