Cutting animal agriculture buys time to get off fossil fuels: study

Good News Notes:

Eliminating animal agriculture over the next 15 years would effectively stop global warming in its tracks – largely halting the increase of greenhouse gases for the next 30 years, according to a recent study in PLOS Climate.

The largest contributor to that decrease in heating would be a massive expansion in prairie, forest and grassland as the global economy converts away from land-dependent practices like cattle-raising, said co-author Patrick Brown, a Stanford biochemistry professor, according to a statement.

Brown is hardly impartial: in addition to his scientific credentials, he is the founder and CEO of plant-based protein company Impossible Foods, which is valued at an estimated $7 billion and aims to go public sometime this year – and would stand to benefit handsomely from a hard shift away from animal farming.

Nonetheless, the dynamics the paper describes are well understood. We have long known that animal agriculture is a potent source of greenhouse gasses, primarily as a result of methane and nitrous oxide released from livestock waste. 

These are more significant problems, molecule for molecule, than the carbon dioxide released from tailpilpes and smokestacks. For its first century in the atmosphere, methane – released from cow burps and hog waste pits – warms the atmosphere between 25 and 80 times more intensely than carbon dioxide, which it gradually degrades into, according to Intergovernmental Panel on Climate Change (IPCC) data.

Nitrous oxide is even worse, rising from manure pits and fertilizer to the atmosphere, where it’s heating effect is about 260 times as much as carbon, according to the IPCC.

Meanwhile, livestock takes up about 80 percent of the world’s agricultural land – about half the habitable surface of the earth though much of this is unsuited for crops – though it provides less than 20 percent of the calories in the world diet, according to Our World in Data. 

Much of this expansion in farmland, and particularly that devoted to cattle and cattle-feed, has generally come at the expense of forest and other wildlands, which pull carbon dioxide from the atmosphere as they grow. A third of the world’s forests and two-thirds of its grasslands have been lost permanently since the last ice age – with half of that loss occurring in the last century, according to the scientific online publication Our World in Data.

By putting together these two factors – the reduction in emissions with the increase in wildlands –  Brown and his coauthor Michael Eisen found that the global switch to a plant-based diet would have the same effect as cutting carbon dioxide emissions by 68 percent.

Since the primary source of carbon dioxide is the burning of fossil fuels in cars and powerplants, this measure would also buy disproportionate time, Brown and Eisen said. 

It would also get the world about halfway to the emissions cuts necessary to keep global warming below the dangerous red line of 2 degrees Celsius (3.6 degrees Fahrenheit.) 

The reductions would take place as methane pollution from animal farms slow and stop, and methane levels in the air begin to degrade as farms turned to forests and ranchlands to pasture – both pulling down carbon.

“As the methane and nitrous oxide emissions from livestock diminish, atmospheric levels of those potent greenhouse gasses will actually drop dramatically within decades,” Brown said in a statement. “And the CO2 that was released into the atmosphere when forests and wild prairies were replaced by feed crops and grazing lands can be converted back into biomass as livestock are phased out and the forests and prairies recover.”

Ninety percent of the benefits could be attained by just removing ruminants like cattle and sheep, the study found, both of which need lots of land and are prone to methane-producing burps.

Brown contends that pivoting off eating animals – or at least beef – is less far-fetched than it sounds. Companies like Impossible Inc. and Beyond Meat have helped bring vegan meats mainstream over the past five years…”

View the whole story here:

Leave a Reply