2019年11月6日 星期三

Climate Fwd: Know your organic food

Also, Tuesday's elections and climate

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Tyler Varsell

By Eduardo Garcia

Demand is booming for organic food. From 2013 to 2018, sales increased nearly 53 percent to almost $48 billion, according to the Organic Trade Association. That sounds like good news for the environment, but is it really?

The first thing to bear in mind is that agriculture, in general, is responsible for a lot of greenhouse gas emissions. In the United States, farming accounts for roughly 9 percent of emissions. About half of those come from the soil. That's largely because fertilizers, once applied to farmland, generate emissions of nitrous oxide, the third-most-abundant greenhouse gas.

Some organic farming practices, like crop rotation and the use of cover crops, additional plants that can help control erosion and pests, help keep nitrous oxide emissions in check. That's because they promote healthy soil, and healthy soil releases less nitrous oxide.

Other practices, though, like tilling the soil to get rid of weeds (instead of spraying chemicals), have the opposite effect. Tilling encourages nitrous oxide emissions. Moreover, because it typically produces less food per acre, organic farming tends to need more land, workers and organic fertilizer to stay competitive. That larger scale means larger greenhouse gas emissions.

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"There's pretty good peer-reviewed science arguing that the carbon footprint would actually expand if we were to see a widespread shift to organic, versus having the productivity benefits of conventional production," said Michael Doane, the global managing director for sustainable food and water at The Nature Conservancy.

Julius McGee, an assistant professor of sociology at Portland State University, said that organic farming had a high carbon footprint because it's been co-opted by industrial growers that supply big-box stores.

"Large organic retailers rely on cheap organic foods and, in order to produce organics cheaply, you oftentimes operate under the same model as industrial agriculture where you try to reduce costs, and for that you need more inputs, which contributes to more greenhouse gas emissions," Dr. McGee said.

These retailers, he said, sell under a "gentrification model" that targets middle class buyers — those who can afford to pay a premium for organic food — displacing small farmers selling directly to people via farmers' markets, community supported agriculture groups or online.

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Regardless of whether they have an organic certificate, Dr. McGee said, small farmers tend to have a lower carbon footprint because they "engage in a deeper relationship with the farm and the land." That often involves growing a wider variety of crops, and smaller farmers don't typically package their products in single-use plastics or transport them to buyers hundreds of miles away.

Not everybody agrees. Rodale Institute, a nonprofit group that promotes organic farming, argues that some of these studies fail to properly measure how much planet-warming carbon dioxide the soil can absorb when it is cultivated using sustainable methods. Rodale estimates that organic farmland can potentially sequester more carbon than is currently emitted.

But greenhouse gases are only part of the story. The synthetic herbicides and pesticides used in conventional agriculture can be harmful to farm workers and wildlife, especially pollinators and birds, while the natural-gas derived fertilizers are responsible for deadly algae blooms and high methane emissions.

The bottom line: Over all, organic food is probably better for the planet, even if the emissions picture is complex. If you can afford to buy organic, try to go small and local.

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Virginia Democrats made big gains in Tuesday's election and the implications for climate change policy are potentially big, too.

For the first time in more than two decades, Democrats will control both the House of Delegates and the State Senate. That significantly increases the likelihood that the state will join a regional initiative designed to reduce greenhouse gas emissions.

Governor Ralph Northam, a Democrat, had long proposed that Virginia join the 10-state program, known as the Regional Greenhouse Gas Initiative. He was stymied in the past, though, when Republicans inserted language into a budget bill that prevented the state from becoming a member.

Under the program, states cap the planet-warming carbon dioxide pollution from power plants and then trade permits for emissions.

Vicki Arroyo, executive director of the Georgetown Climate Center, a research arm of Georgetown University Law School, called the election results "very consequential." She noted that Virginia has been trying to shift away from coal and rely more on renewable energy sources like solar and wind. Joining the regional initiative, she said, would bolster those efforts.

"This new Legislature opens doors to Virginia joining RGGI and enacting legislation to support and build upon recent executive orders on climate change," Ms. Arroyo said.

This year, the Democratic Party of Virginia unanimously approved resolutions supporting a move to 100 percent renewable energy and embracing the Green New Deal, an ambitious plan to tackle climate change and provide living-wage guarantees.

A spokesman for the Democratic National Committee also noted that several candidates in Virginia directly addressed the threats that climate change is posing to the state, notably flooding linked to rising sea levels.

Environmentalists poured significant money into the election. The League of Conservation Voters, for example, spent $1.5 million on direct mail and other advertising in Virginia.

Evan Webber, political director for the Sunrise Movement, a climate advocacy group that helped design the Green New Deal, called the election a "road map" for Democrats. "When candidates reject corporate money and run on ambitious plans to tackle climate change, lower utility costs, and create good jobs, they win," he said in a statement.

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