Opinion | Peter Singer: Fix Your Diet, Save the Planet – The New York Times

MELBOURNE, Australia — The year of the first Earth Day, 1970, was the year I stopped eating meat. I didn’t do it to save the Earth, but because I realized that there is no ethical justification for treating animals like machines for converting feed into meat, milk and eggs. It is wrong to ignore or discount the interests of sentient beings because they are not members of our species.

In the United States and beyond, giant agribusiness corporations continue raising animals in ways that disregard their welfare, never allowing pigs or chickens to walk outside, crowding hens who lay eggs into cages that prevent them from stretching their wings and breeding chickens to grow so fast that their immature leg bones struggle to bear their weight.

Boycotting this monstrous abuse of billions of animals each year is a powerful reason for not eating meat, but the outsize contribution of meat and dairy products to climate change is for me now an equally urgent part of shifting to a plant-based diet. But we need not be hard-line about avoiding all animal products. If everyone chose plant-based foods for just half their meals, we would have fewer animals suffering, and a tremendously better shot at avoiding the most dire consequences of climate change.

Meat and dairy production are major sources of methane, a powerful greenhouse gas. The Intergovernmental Panel on Climate Change calculates that releasing into the atmosphere a ton of methane will, over a century, raise the temperature of our planet by 28 times as much as releasing a ton of carbon dioxide. That would be bad enough, but the impact is even more lopsided in the shorter term: Because methane breaks down much more rapidly than carbon dioxide, over 20 years, that ton will warm the planet as much as 84 tons of carbon dioxide.

It is already too late to prevent climate change from irreversibly transforming ecosystems, causing immense loss of biodiversity, inundating low-lying coastal regions and destroying the livelihoods of many dependent on stable rainfall patterns. Those 20 years are about the time we have left to prevent far more devastating change.

This means we can do something for the planet every time we eat. And if Americans were to replace 50 percent of all animal-based foods with plant-based alternatives by 2030, that alone would help them get a quarter of the way toward hitting the U.S. climate target under the Paris agreement.

Admittedly, slowing climate change would be much easier — and fairer — if governments were to tax animal products in proportion to the damage they do to the climate. But in the absence of meat and dairy taxes, the power lies with those who consume animal products, and with the institutions that provide food for many of us.

Climate change isn’t the only reason that a decision to stop eating animals makes a fitting Earth Day resolution. Forty percent of the clearing and burning of tropical forests is to create pasture for cattle grazing, the largest driver of deforestation of the Brazilian Amazon. In addition to the substantial carbon emissions, the destruction of tropical forests threatens mass extinctions, including the loss of species still unrecorded. Much of the remainder of the cleared land is used for growing soy, more than three-quarters of which will be fed to animals for meat and dairy production, a process that wastes most of the crop’s food value.

As if that isn’t enough, factory farms make stinking neighbors, polluting local air, attracting flies in huge numbers and polluting local rivers and lakes. They are also a risk to public health, helping new viruses to emerge and creating resistant bacteria that increasingly leave us defenseless against infections

Perhaps the most positive change since I wrote the book “Animal Liberation” is the rise of vegan eating. In 1975 it was rare to encounter a vegetarian in Western societies, except in certain communities. Vegan and vegetarian diets could be found among Seventh Day Adventists, followers of Rastafarianism, some members of the Nation of Islam and those with a Hindu background. Now there are 1.3 million vegans in Britain, or 2 percent of the country’s population, and in the United States, estimates of the proportion of vegans in the population range from 0.5 percent to 6 percent. Vegan foods, clearly labeled, are in many supermarkets and on many restaurant menus.

But even if there were 10 times as many vegans in the world, that would not be enough to save the planet or end factory farming. Persuading the majority of the world’s affluent people to at least halve their consumption of animal products would achieve much more.

Is that realistic? When I was young, I went to parties and meetings at which the air was so thick with cigarette smoke that even the next morning, my clothes smelled of it. I never thought that would change, but it did. Twenty years ago, sodomy was a crime in some U.S. states and the widespread acceptance of same-sex marriage was unthinkable. There is no reason attitudes to industrial animal production cannot change just as fast.

Peter Singer is a professor of bioethics at Princeton and the author of the forthcoming book “Animal Liberation Now.”

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