6 ways agriculture impacts global warming

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Sure, agriculture provides us with the food we all eat every day. But do you know how those agricultural practices impact global warming? Turns out there's some pretty big impacts, on both the sustainable and industrial sides of the equation; employing sustainable practices, like organic agriculture, has huge potential to help in the fight against global warming, and maintaining the status quo with widespread industrial agricultural practices will continue to be terribly detrimental for the climate. Dig deeper to learn more about the ways agriculture impacts global warming.

Positive Impacts

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1. Carbon sequestration in soils

We've said it before and we'll say it again: Organic agriculture can remove from the air and sequester 7,000 pounds of carbon dioxide per acre per year. The Rodale Institute study that found that staggering number also found that, when properly executed, organic agriculture does not compromise yield. As a matter of fact, in drought years, it increases yield, since the additional carbon stored in soil helps it to hold more water. In wet years, the additional organic matter in the soil wicks water away from plant roots, limiting erosion and keeping plants in place. Both of those attributes will also benefit organic ag's ability to adapt to the higher highs (and lower lows) of climate change.

2. Agriculture as carbon cap and storage

Scaling up from soil to the entire industry, the agricultural sector could be "broadly carbon neutral" by 2030, effectively negating the agricultural industry's humongous carbon footprint. Translation: We would avoid emitting a whopping 2 gigatonnes -- that's 2 billion metric tonnes -- of carbon dioxide. Given that, practicing sustainable agriculture, along with reducing deforestation, is far more effective, and billions of dollars cheaper, than investing in carbon cap and storage at the world's power plants.

3. Local food systems and greenhouse gas emissions

Combined with the two big green steps mentioned above, local food systems can help reduce agriculture's impact on global warming even further. The example that resident sustainability engineer Pablo used for calculation -- cherries grown close enough to be transported by truck rather than airplane -- won't apply to everything, but the lesson is clear: Employing organic agricultural practices has significant potential to help mitigate climate change and strengthen local, seasonal food systems.

Negative Impacts

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4. Industrial agriculture's huge carbon footprint

On the other side of the equation, industrial agriculture -- the practice currently employed by the majority of the developed world -- has a hugely negative impact on global warming. The U.S. food system contributes nearly 20 percent of the nation's carbon dioxide emissions; on a global scale, figures from the Intergovernmental Panel on Climate Change (IPCC) say that agricultural land use contributes 12 percent of global greenhouse gas emissions. Supporting industrial agriculture perpetuates these disturbing practices.

5. Greenhouse gas emissions from fertilizer and pesticide use

But wait, there's more! If we consider some of the embodied energy required for industrial ag, it gets worse. According to Will Allen, green farmer extraordinaire, including all the "manufacture and use of pesticides and fertilizers, fuel and oil for tractors, equipment, trucking and shipping, electricity for lighting, cooling, and heating, and emissions of carbon dioxide, methane, nitrous oxide and other green house gases" bumps the impact up to between 25 and 30 percent of the U.S.'s collective carbon footprint. That's a big jump.

6. Land use changes and agriculture

It's not just the actual farming (if you can call it that) that makes industrial agriculture so detrimental. In almost every case, land use changes -- say, deforestation, or paving over green space for suburban expansion -- result in more surface warming. One exception: When deforestation occurs to create more agricultural land. That's right, deforestation results in surface warming, with the exception being conversion to agriculture. Wait, what?

The difference here is that we're talking surface warming, rather than changing atmospheric conditions, and, while chopping down a forest might make it feel cooler, forests have a much greater potential to sequester carbon dioxide than does monocultural, industrial agriculture (and there goes the baby with the bathwater). The bottom line: The effect of land use conversion on rising surface temps is an underestimated component of global warming, and just because it feels cooler today than it did yesterday does not mean big-time climate change is right around the corner.

Tags: Global Warming Causes | Global Warming Solutions

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