Two apologies first:

1. Apologies that this post is nothing like my usual content. Actually I don’t apologise for this, because this concise and powerful summary felt too important not to challenge my readers with.
2. Apologies to Jonathan Safran Foer for copy/pasting these pages from We are the Weather: Saving the Planet Begins at Breakfast. I hope I can be forgiven for trying to spread the message.

Degrees of Change

• From one hundred thousand to ten thousand years ago, mastodons, mammoths, dire wolves, saber-toothed cats, and giant beavers roamed a world of ice. The average global temperature was four to seven degrees Celsius colder than it is today.
• Fifty million years ago, the Arctic was filled with tropical rainforests. Crocodiles, turtles, and alligators lived in the polar forests of what is now Canada and Greenland. Two-hundred-pound penguins waddled in Australia, and palm trees grew in Alaska. There were no polar ice caps. The Antarctic seas were warm enough for a balmy swim, and around the equator, the oceans were the temperature of a hot tub. Earth was five to eight degrees Celsius warmer than it is today.
• As with body temperature, a few degrees can be the difference between health and crisis.

The First Crisis

• There have been five mass extinctions. All but the one that killed the dinosaurs were caused by climate change.
• The most lethal mass extinction occurred 250 million years ago, when volcanic eruptions released enough carbon dioxide (CO2) to warm the oceans by about ten degrees Celsius, ending 96 percent of marine life and 70 percent of life on land. The event is known as the Great Dying.
• Many scientists call the geological age from the Industrial Revolution to the present the Anthropocene, the period during which human activity has been the dominant influence on the earth. We are now experiencing the sixth mass extinction, often referred to as the Anthropocene extinction.
• Taking into account natural mechanisms that influence climate, human activity is responsible for 100 percent of the global warming that has occurred since the beginning of the Industrial Revolution, around 1750.
• The current climate change is the first caused by an animal and not by a natural event.
• The sixth mass extinction is the first climate crisis.

The First Farming

• If human history were a day, we were hunter-gatherers until about ten minutes before midnight.
• Humans represent 0.01 percent of life on Earth.
• Since the advent of agriculture, approximately twelve thousand years ago, humans have destroyed 83% of all wild animals and half of all plants.

Our Planet Is an Animal Farm

• Globally, humans use 59 percent of all the land capable of growing crops to grow food for livestock.
• One-third of all the fresh water that humans use goes to livestock, while only about one-thirtieth is used in homes.
• Seventy percent of the antibiotics produced globally are used for livestock, weakening the effectiveness of antibiotics to treat human diseases.
• Sixty percent of all mammals on Earth are animals raised for food.
• There are approximately thirty farmed animals for every human on the planet.

Our Population Growth Is Radical

• Before the Industrial Revolution, the average life expectancy in Europe was about thirty-five years. It is now about eighty.
• It took two hundred thousand years for the human population to reach one billion, but only two hundred more years to reach seven billion.
• Every day, 360,000 people –roughly equal to the population of Florence– are born.

Our Animal Farming Is Radical

• In 1820, 72 percent of the American workforce was directly involved in agriculture. Today, 1.5 percent is.
• Like the video game console, the factory farm was an invention of the 1960s. Before then, food animals were raised outdoors in sustainable concentrations.
• Between 1950 and 1970, the number of American farms declined by half, the number of people employed in farming declined by half, and the size of the average farm doubled.
• During that time, the size of the average chicken also doubled.
• In 1966, distorting contact lenses were invented to make it harder for chickens to see their increasingly unnatural surroundings, thereby easing the stress that caused violent pecking and cannibalism. The lenses were considered too burdensome for farmers, so automated debeakers –which burn off the ends of chickens’ faces– became the industry norm.
• In 2018, more than 99 percent of the animals eaten in America were raised on factory farms.

Our Eating Is Radical

• The current level of meat and dairy consumption is the equivalent of every person alive on the planet in 1700 eating 950 pounds of meat and drinking 1,200 gallons of milk every day.
• There are twenty-three billion chickens living on Earth at any given time. Their combined mass is greater than that of all other birds on our planet.
• Humans eat sixty-five billion chickens per year.
• On average, Americans consume twice the recommended intake of protein.
• People who eat diets high in animal protein are four times as likely to die of cancer as those who eat diets low in animal protein are.
• Smokers are three times as likely to die of cancer as nonsmokers are.
• In America, one out of every five meals is eaten in a car.

Our Climate Change Is Radical

• We are currently in the Quaternary glaciation, a period with continental and polar ice sheets. Such a period is more commonly known as an ice age.
• According to models of cyclical climate change, Earth should be experiencing a period of slight cooling right now.
• Nine of the ten warmest years on record have occurred since the first YouTube video, “Me at the Zoo,” was posted, in 2005.
• During the Great Dying, a series of Siberian volcanoes produced enough lava to cover the United States up to three Eiffel Towers deep.
• Humans are now adding greenhouse gases to the atmosphere ten times faster than the volcanoes did during the Great Dying.

Why Greenhouse Gases Matter

• Sunlight passes through the atmosphere and heats the Earth. A portion of that heat bounces back into space. Greenhouse gases in the atmosphere trap some of the outgoing heat, as a blanket traps body heat.
• Life on Earth depends on the greenhouse effect. Without it, Earth’s average temperature would be near zero degrees Fahrenheit, instead of fifty-nine degrees.
• CO2 accounts for 82 percent of the greenhouse gases emitted by human activity. The majority is emitted by industry, transport, and electrical use.
• For the eight hundred thousand years before the Industrial Revolution, concentrations of greenhouse gases in our atmosphere remained stable.
• Since the Industrial Revolution, the concentration of CO2 in the atmosphere has increased by about 40 percent.
• Methane and nitrous oxide are the second and third most prevalent greenhouse gases in the atmosphere.
• Animal agriculture is responsible for 37 percent of anthropogenic methane emissions and 65 percent of anthropogenic nitrous oxide emissions.
• Between the advent of factory farming in the 1960s and 1999, concentrations of nitrous oxide in the atmosphere grew about two times faster, and concentrations of methane grew six times faster, than they had over any previous forty-year period during the last two thousand years.

Climate Change Is a Ticking Time Bomb

• Different climate scientists have given different deadlines by which we must halt greenhouse gas emissions (GHGs). Such statements usually take the form “We have X years to solve climate change.”
• Climate change is not a disease that can be managed, like diabetes; it is an event like a cancerous tumor that needs to be removed before the cells fatally multiply. The planet can handle only so much warming before positive feedback loops create “runaway climate change.”
• One of the most powerful feedback loops is called the albedo effect. White ice sheets reflect sunlight back into the atmosphere. Dark oceans absorb sunlight. As the planet warms, there is less ice to reflect sunlight, and more dark ocean and land to absorb it. Oceans become hotter, melting ice faster.
• The former United Nations climate chief Christiana Figueres has said that we have until 2020 to avoid temperature thresholds leading to runaway, irreversible climate change.

Because Climate Change Is a Ticking Time Bomb, Not All Greenhouse Gases Matter Equally

• Methane has 34 times the global warming potential (GWP)—the ability to trap heat—as CO2 does over a century. Over two decades, methane is 86 times as powerful.
• If CO2 were the thickness of an average blanket, imagine methane as a blanket thicker than LeBron James is tall.
• Nitrous oxide has 310 times the GWP of CO2. Imagine a blanket so thick you could commit suicide by jumping off it.
• When global emissions are calculated, greenhouse gases are converted to carbon dioxide equivalents (CO2e). Calculations are usually based on a hundred-year timescale. This means that one metric ton of methane should be counted as thirty-four metric tons of CO2 in an overall greenhouse gas assessment.
• We can think of our atmosphere as a budget and our emissions as expenses: because methane and nitrous oxide are significantly larger greenhouse expenses than CO2 in the short term, they are the most urgent to cut.
• Because they are primarily created by our food choices, they are also easier to cut.

Why Deforestation Matters

• Trees are “carbon sinks,” which means they absorb CO2.
• Imagine a bathtub filling up with water. If the drain slows, the tub will fill up more quickly. This is similar to the earth’s photosynthetic capacity: already, humans are pumping greenhouse gases into the atmosphere at a rate that exceeds Earth’s ability to regulate them, but vegetation currently stores a substantial amount of CO2—about one-quarter of anthropogenic emissions, or about half a century’s worth of emissions at the current rate.
• The more forests we destroy, the closer we come to plugging the drain.
• Allowing tropical land currently used for livestock to revert to forest could mitigate more than half of all anthropogenic GHGs.
• Trees are 50 percent carbon. Like coal, they release their stores of CO2 when burned.
• Forests contain more carbon than do all exploitable fossil-fuel reserves.
• The cutting and burning of forests is responsible for at least 15 percent of global GHGs per year.
• According to Scientific American, “By most accounts, deforestation in tropical rainforests adds more carbon dioxide to the atmosphere than the sum total of cars and trucks on the world’s roads.”
• About 80 percent of deforestation occurs to clear land for crops for livestock and grazing.
• Every year, wildfires in California create more greenhouse gas emissions than the state’s progressive environmental policies save.
• Burning forests is like further opening the tap while clogging the drain.

Not All Deforestation Matters Equally

• In 2018, Brazil elected Jair Bolsonaro as president. Bolsonaro campaigned on a plan to develop previously protected swaths of the Amazon (i.e., deforestation). It has been estimated that Bolsonaro’s policy would release 13.2 gigatons of carbon—more than two times the annual emissions of the entire United States.
• Animal agriculture is responsible for 91 percent of Amazonian deforestation.

Animal Agriculture Causes Climate Change

• As they digest food, cattle, goats, and sheep produce a significant amount of methane, which is mostly belched but also exhaled, farted, and passed in the waste of the animal.
• Livestock are the leading source of methane emissions.
• Nitrous oxide is emitted by livestock urine, manure, and the fertilisers used for growing feed crops.
• Livestock are the leading source of nitrous oxide emissions.
• Animal agriculture is the leading cause of deforestation.
• According to the United Nations Framework Convention on Climate Change, if cows were a country, they would rank third in greenhouse gas emissions, after China and the United States.

Animal Agriculture Is a/the Leading Cause of Climate Change

• When assessing animal agriculture’s overall contribution to greenhouse gas emissions, estimates range dramatically depending on what is included in the calculation.
• The Food and Agriculture Organization (FAO) of the United Nations asserts that livestock are a leading cause of climate change, responsible for approximately 7,516 million tons of CO2e emissions per year, or 14.5 percent of annual global emissions.
• The FAO calculation includes the CO2 emitted when forests are cleared for animal feed crops and pastures, but it does not take into account the CO2 that those forests can no longer absorb. (Imagine a life insurance policy that covered the cost of the funeral but not future lost wages.) Among other things not included in its calculation is the CO2 exhaled by farmed animals, even though, in the words of one environmental-assessment specialist, “livestock (like automobiles) are a human invention and convenience, not part of pre-human times, and a molecule of CO2 exhaled by livestock is no more natural than one from an auto tailpipe.”
• When researchers at the Worldwatch Institute accounted for emissions that the FAO overlooked, they estimated that livestock are responsible for 32,564 million tons of CO2e emissions per year, or 51 percent of annual global emissions –more than all cars, planes, buildings, power plants, and industry combined.
• We do not know for sure if animal agriculture is a leading cause of climate change or the leading cause of climate change.
• We know for sure that we cannot address climate change without addressing animal agriculture.

It Will Be Impossible to Defuse the Ticking Time Bomb Without Reducing Our Consumption of Animal Products

• Scientists estimate that to keep global warming at or below two degrees Celsius—the goal of the Paris accord—we have a CO2e emissions budget of 565 gigatons by 2050.
• According to a recent Johns Hopkins University report on the role of diet in climate control, “If global trends in meat and dairy intake continue, global mean temperature rise will more than likely exceed 2°C, even with dramatic emissions reductions across non-agricultural sectors.”
• Home-front efforts during WWII were not enough, on their own, to win the war, but the war could not have been won without home-front efforts. Changing how we eat will not be enough, on its own, to save the planet, but we cannot save the planet without changing how we eat.

Not All Actions Are Equal

• The most optimistic estimates suggest that, even assuming international cooperation, a global conversion to wind, water, and solar power would take more than twenty years and require a hundred-trillion-dollar investment.
• Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research: “The maths is brutally clear: while the world can’t be healed within the next few years, it may be fatally wounded by negligence [before] 2020.”
• Adjusted for inflation, the global cost of WWII was fourteen trillion dollars.
• The four highest-impact things an individual can do to tackle climate change are eat a plant-based diet, avoid air travel, live car-free, and have fewer children.
• Of those four actions, only plant-based eating immediately addresses methane and nitrous oxide, the most urgently important greenhouse gases.
• Most people are not in the process of deciding whether to have a baby.
• Eighty-five percent of Americans drive to work. Few drivers can simply decide to stop using their cars.
• For Americans, 29 percent of air travel in 2017 was for business purposes, and 21 percent was for “personal non-leisure purposes.” Businesses must rely more on remote communication, “personal non-leisure” flights must be reduced, and personal leisure flights can and must be cut, but the fact remains that a sizeable portion of air travel is unavoidable.
• Everyone will eat a meal relatively soon and can immediately participate in the reversal of climate change.

Not All Foods Are Equal

• Pounds of CO2e associated with a serving of each food:
  Beef: 6.61
  Cheese: 2.45
  Pork: 1.72
  Poultry: 1.26
  Eggs: 0.89
  Milk: 0.72
  Rice: 0.16
  Legumes: 0.11
  Carrots: 0.07
  Potatoes: 0.03
• Not eating animal products for breakfast and lunch has a smaller CO2e footprint than the average full-time vegetarian diet.

How to Prevent the Greatest Dying

• To meet the Paris accord’s two-degree goal, an individual’s annual CO2e budget must not exceed 2.1 metric tons by 2050.
• While citizens of different countries have dramatically different CO2e footprints—the average American’s is 19.8 metric tons per year, the average Frenchman’s is 6.6 metric tons per year, and the average Bangladeshi’s is 0.29 metric tons per year—the average global citizen has a CO2e footprint of approximately 4.5 metric tons per year.
• Not eating animal products for breakfast and lunch saves 1.3 metric tons per year.