Cedar and Pearl

A changing climate for farms

By John Piotti | Mar 15, 2016

I found myself a few months ago speaking to a room of environmentalists at a forum about climate change. I had been invited to talk about farming. I focused on a single topic: how I’m alarmed to increasingly hear Mainers say that a warming climate, which they dread in so many ways, would at least help our farmers.

I was eager to know if others in the room were hearing the same, and wondering if this group of activists had suggestions on how we might better inform the public about climate change’s threat to farming in Maine.

Instead, my words surprised many in the audience — and did so for what to me was an unbelievable reason: because even many of these environmentalists thought that climate change would at least help Maine farmers.

I think most people understand how a warming climate will cause impacts that go far beyond just rising temperatures, because rising temperatures, in and of themselves, bring about other changes.

For instance, we have become accustomed to thinking that a hotter planet will raise sea level, intensify hurricanes, and threaten millions who live on vulnerable coastlines. And we certainly comprehend that, because of rising temperatures, farming may no longer be possible in many hot and dry places that will become even hotter and drier.

But in cool and relatively wet parts of the world, the potential impact of climate change on farming seems bearable. And then here in Maine, where we perceive the growing season to be so short compared to bountiful agricultural regions like California, we sense a silver lining.

But in truth, a warming climate will do far more than lengthen Maine's growing season — and none of it is good. Climate change is already exposing Maine crops to new pests, disrupting the timing of natural pollinators, and increasing the frequency of severe storms that wash out newly planted seeds and damage growing crops. These impacts are only expected to increase.

Meanwhile, longer and drier summers will threaten crops that aren’t irrigated — the vast bulk of what Maine grows. And warm spells occurring anywhere between November and April will force fruit trees and other perennials to bud early, putting those crops at risk. (Last November’s record-high temperatures caused apple trees to blossom in parts of southern Maine. The impact on this year’s harvest is likely to be modest; but if this kind of weather becomes more frequent and widespread in the future, the negative impacts will mount.)

At the same time, any hoped-for benefits of a longer growing season may prove ethereal. Gaining extra weeks in spring and fall may not help farmers at all if those weeks correspond to the amount of time in midsummer when — because of high heat or lack of water — nothing is growing. And the arrival of warmer temperatures earlier in the year does no good if heavy spring rains keep tractors off fields at precisely the time farmers want to plant.

Beyond that, it’s worth noting that the current length of the growing season is not a major barrier to Maine's agricultural production. If I asked Maine farmers to list the top 10 items adversely affecting their operations, the length of the growing season would not appear on many lists. Indeed, the current growing season is well-suited to Maine's largest crop, potatoes; and dairy production — which forms the other anchor of Maine agriculture — benefits from cooler temperatures.

True, a longer growing season theoretically would help farmers who focus on warm-season vegetables. But I wonder how useful this will really prove, given that smart and simple strategies that allow farmers to extend their seasons already exisit — strategies that often bring additional benefits.

For instance, hoop houses enable farmers to manage water and temperature in ways that would never be possible on an open field. Ironically, I expect that global warming, which will increasingly result in more extreme and less predictable weather, will push many vegetable farmers to raise more crops in controlled environments, where any benefits that might result from a longer growing season would not be needed — or utilized.

Simply put, the negative impacts of climate change on farms in Maine are real and growing, while the one potential benefit — a longer growing season — may not be much of a benefit at all.

But don't be too discouraged. There may well be a silver lining, just of a different sort.

Agriculture and climate change are interwoven in powerful ways. On the negative side, agriculture is a leading cause of climate change, responsible for roughly half of all human-caused greenhouse gas emissions.

We burn fossil fuels to operate farm equipment and irrigation systems, as well as to transport, process, and store our food. We apply to our fields a wide range of chemicals and fertilizers that — through both their manufacture and use — release greenhouse gases to the atmosphere. Meanwhile, our livestock and manure piles emit methane.

Beyond all that, we release carbon from our soils into the atmosphere. This occurs as a direct result of certain agricultural practices, including excessive tilling of fields and short-sighted methods of clearing land. A staggering one-third of all the carbon in our atmosphere has been released from the soil — and most of that has been released in the last 150 years.

The good news is that farming — whether in Maine or beyond — has the potential to help mitigate climate change by recapturing carbon in the soil. Not all farming reduces atmospheric carbon. But the right farming practices applied in the right places to the right degree can make a real difference.

The concept known as “carbon farming” was elevated to broader public awareness last fall in a Washington Post column entitled, “A Secret Weapon to Fight Climate Change: Dirt.” Coupled with aggressive emission reductions, carbon farming provides a practical way — perhaps the only way — to reduce atmospheric carbon to acceptable levels.

At its simplest, carbon farming is about rebuilding soil through various well-known techniques, such as the active use of cover crops, planting methods that minimize or eliminate the need for tilling, wider use of perennial crops, and interspersing different types of crops — including trees — in creative ways.

Maine is poised to play an important role. That’s because many of Maine’s farmers are already following these kinds of practices to some degree, and because farming here is of a size and scale that lends itself to doing even more. Granted, we need more research into what practices work best. We also need federal policy to spur faster change on the ground. But public interest in farming is growing so fast that I think that’s coming.

There is so much that our farmers do for us. Farmers don’t only raise the food that sustains us, but steward the fields and woods we cherish for hiking and hunting, scenery and solace. But beyond that, with the right resources and support, our farmers can help restore our planet.

John Piotti of Unity runs Maine Farmland Trust. His column “Cedar and Pearl” appears every other week.

If you appreciated reading this news story and want to support local journalism, consider subscribing today.
Call (207) 594-4401 or join online at waldo.villagesoup.com/join.
Donate directly to keeping quality journalism alive at waldo.villagesoup.com/donate.
Comments (0)
If you wish to comment, please login.
Note: If you signed up using our new subscriber portal, your username is the email address you registered with and your password is in all caps