"Methane emissions are driving climate change".‍

Cutting methane emissions is the "quickest route to slowing global heating."

‍

‍What is methane?

There are three main greenhouse gases (GG's): the majority is carbon dioxide (CO2) at 72%, then methane (CH4) at 21%, and nitrous oxide (N2O) at 5%.

Methane is 100 times as potent a greenhouse gas as carbon dioxide! But it breaks down into carbon dioxide and water after 13 years, whereas carbon dioxide lasts hundreds, if not thousands, of years. For a more detailed discussion of the GWP or global warming potential of GG's, see this publication.

Imagine this.

You’re in a room for 10 days and given one ton of carbon dioxide.  Let's say that would raise the temperature as much as plugging in 1 space heater.

Now you're given one ton of methane. That would raise the temperature as much as plugging in 100 heaters! 

‍

The  CO2 heater works for 10 days, but most of the methane heaters burn out after 2.

Over the years,  methane's prominence as a GG has been debated.

Until now.  

More recent climate models employ a new formula that takes methane's temporal dynamics into account, and satellite tracking now allows its direct measurements. It's emissions and impacts are worse than we thought. Let's go back to our analogy.

Even though the hundred methane heaters were only on for 2 days, they immediately and drastically raised the temperature, wreaking havoc! You got heatstroke,  lost your plants,  fish in your aquarium, and ice in the cooler.  In reality, heat kills especially the poorest among us who cannot  move or access A/C,  causes droughts with crop failures and starvation, acidifies oceans endangering marine life, melts polar ice caps, and augments forest fires. Perhaps most importantly, it thaws permafrost and drives us to tipping points of other cataclysmic feedback loops. We are told we have 10 to 20 years to clean up our act in order to avoid the worst impacts of climate change and meet our goal of 1.5 degrees C.  So although methane lasts 'only' 13 years, the punch it packs  is driving global warming in the near term -  which is all we have.

There is another twist to understand methane's importance.

Say for every methane heater you got, one burned out. The temperature would mostly remain the same (but recall it does break down into CO2!).

Now envision there's a sale on heaters, so someone brings you 2 or 3 heaters for every 1 that breaks.

Disaster!

Conversely, say you replace only 1 heater for every 2 that stop working. Aah. The temperature drops, and drops quickly.  Whether methane concentrations are increasing or decreasing  becomes immensely important. ‍

Where does methane come from?‍

The number one source is wetlands, followed by agriculture, fossil fuel production, and food waste. (One third of global food supply is wasted.

What methane sources do we have control over?

There are 3: oil and gas, livestock, and landfills.

‍

‍

Agriculture is responsible for the majority of anthropogenic or 'man-made' methane.

Animal agriculture in particular contributes 32 % of all  human caused methane emissions.

If you look at overall emissions from livestock, they are composed of the most dangerous GG's.

‍

For purposes of this discussion, we do not address nitrous oxide, the forgotten GG.  It is 273 times more potent than CO2, and though more devastating on a per ton basis than even methane, it 'only' accounts for 5% of global carbon dioxide equivalents (see first pie chart). As nitrous oxide comes mainly from fertilizer and manure,  eliminating livestock would eradicate 65% of nitrous oxide global emissions!

"Emissions from livestock production are expected to continue rising as the global population nears 10 billion by midcentury and diets shift to incorporate more meat." (Consumption of meat from ruminant animals like cattle  is expected to increase about 90% by 2050.) " If current trends for food demand and production continue, emissions from the food system alone would likely push global warming beyond 1.5° C, even if all non-food system emissions were immediately eliminated. Consumption of dairy and meat, particularly from cattle, is expected to account for over half of future warming associated with the food system, with emissions from meat production alone contributing 0.2–0.44°C of warming by the end of the century."

Translation: we will not meet our climate goal of 1.5 degrees without eating less meat and dairy, even if we achieve net 0 by 2050.

You hear it all the time on the news . Climate change is happening more rapidly than  scientists had predicted.  Before now, calculating climate's trajectory has been based on mathematical models using assigned GWP's (global warming potentials- see above) and estimates arrived at from sampling facilities in what is termed a bottom-up approach.  But technology now employs direct measurement by air samples and satellite tracking where spectrometers  measure CO2, CH4 and N2O in precise amounts and locations: a "top-down" approach. And it turns out, " In the US, where animal production is predominantly highly intensified with confined feeding operations, animal methane emissions may be 39%–90% higher than bottom-up models predict."   "These studies suggest that the United Nation's  Food and Agriculture Organization and other conventional estimates of methane emissions from intensive animal operations are underestimated, matching poorly with atmospheric observations of methane the impacts of eating less meat and dairy is very likely significantly more than we imagined.  It is said, "..reducing livestock emissions is more important than ever. Research shows that doing so would come with even larger climate benefits than previously imagined."  "One thing is clear: we won’t be able to avoid the worst impacts of global warming without tackling emissions from livestock."

• Bill Gates:

• From Greta Thunberg's The Climate Book: "But short of such radical options as completely swearing off air travel or car driving...there are precious few actions that each of us could adopt on our own that would rival shunning beef in expected impact. Replacing US beef with diverse, rigorously nutritious plant-based diets, which deliver exactly the same protein mass results in an emission reduction of about 350 millions tons of CO2eq per year nationwide. As a yardstick, these savings are over 90% of the full emissions of the entire US residential sector. Take it in: replacing beef with plant alternatives would not only vastly improve our health, but it would also reduce greenhouse gas emissions by nearly the same amount as is used today in all our energy intensive dwellings." G. Eshel,  p.342.
• And from the author of the largest study to date of the environmental impacts of agriculture, " 'A vegan diet is probably the single biggest way to reduce your impact on planet earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,' said Joseph Poore, at the University of Oxford, UK, who led the research. 'It is far bigger than cutting down on your flights or buying an electric car,' he said, as these only cut greenhouse gas emissions. 'Agriculture is a sector that spans all the multitude of environmental problems...Really it is animal products that are responsible for so much of this.' "

"But reducing methane emissions now would have an impact in the near term and is critical for helping keep the world on a path to 1.5°C."   "Limiting GHGs from agriculture is urgent because business-as-usual agricultural growth is likely incompatible with limiting warming below 1.5 °C ."

Nonetheless, the beef industry is ramping up its disinformation campaign with myths such these: Hot air: five climate myths pushed by the US beef industry of which methane is one.

"We cannot afford another lost year for food and climate action,” said Emile Frison, an expert speaking on behalf of the International Panel of Experts on Sustainable Food Systems (IPES-Food)".

While the world wrestles with complicated technologic strategies to continue to cater to our appetite for livestock, the answer is simple, immediate,  and staring us in the face!