Our guest blogger is Brian DeVore, Land Stewardship Project.
In 1989, I worked for a farm magazine that claimed global climate change, if real, would actually be good for agriculture since rising carbon dioxide levels would act as some sort of mega plant growth promoter. During the past seven days, I’ve seen firsthand what happens when extreme weather — which many scientists say is an offshoot of climate change — hammers Midwestern agriculture. Guess what: drowning crops have a hard time breathing in CO2.
Last Friday, I was in southwest Iowa, where the Missouri is making lowland corn and soybean fields a soupy mess while threatening the popcorn capital of the world. Today, I spent some time in northwest Minnesota, where yet another ridiculously wet spring is making a mockery of even the latest in tile drainage technology. This kind of extreme weather — more precipitation coming in more intense bursts — is not a once every 10- or even 5-year situation. As we’ve reported in the Looncommons blog before, this is the new norm.
Farmers and other agriculturalists are being forced to take notice. A recent New York Times article reported how ag scientists around the world are beginning to note how many of the failed harvests of the past decade have been the result of weather disasters — floods, drought, unprecedented heat waves.
Many of these scientists are now admitting that global climate change will probably have a net negative effect on agriculture. That’s a tough one to swallow for some, since so many in the scientific community spent the 1990s and 2000s telling us that carbon dioxide (the main contributor to climate change) would boost plant growth so much that it would offset any other negative effects caused by an altered climate.
As the Times reports, such a predictions were based on computer models that failed to take into account back-to-back 100-year floods in the northern Great Plains during 2009 and 2010, or rainstorms so severe that they are setting back decades of advances in soil erosion control. They also didn’t take into account more subtle effects of climate change, like increased humidity-based disease/pest problems in crops.
The good news is that the agricultural scientific community is starting to take this threat to the long-term productivity of agriculture seriously. Last month, a joint position statement on climate change was published by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America — none of these are exactly tree-hugging organizations.
It’s clear the members of these three groups are quite alarmed at the situation. The position statement points out that any benefits from higher CO2 levels will likely be offset by the negative effects of rising temperatures and altered precipitation.
And they say some of the negative effects won’t be the kinds of things that make the TV news. For example, higher soil temperatures alter nutrient and carbon cycling by modifying soil biota. Rainfall amounts — either too much or too little — that are dramatically different than what a particular soil has evolved with will negatively alter soil chemistry and biology as well. Such changes aren’t as dramatic as a million acres of flooded bottom land, but the result can be the same: no crops are harvested come fall.
“Agriculture has an important role to play in responding to climate change, both mitigating its causes and adapting to its unavoidable impacts,” conclude the ASA, CSSA and SSSA in their position statement.
That statement is at once hopeful and brutally practical. Yes, the climate has already changed and we probably can’t change what’s already occurred. But we can also take steps to reduce the effects of such negative impacts while preventing future changes in the climate that could be even more devastating.
The position paper recommends several ways agriculture can play a positive role in both preventing more climate change and mitigating what problems are already present. One strategy is to increase crop diversity. That’s something that’s not likely anytime soon with $7 per bushel corn. But covering more of our land with a diversity of cropping systems can not only help make our soils and field ecosystems more resilient under a brave new climate regime, but it can reduce the amount of CO2 that’s pumped into the atmosphere — thus hopefully preventing more change.
And it';s not just a greater diversity of annual crops that would help. Getting more of the land covered with perennial plant systems like grass would be a tremendous way to trap more greenhouse gases (and improve water quality, by the way).
More perennials in ag can also mitigate the impacts of an already changed climate. While I saw plenty of corn and soybeans under water this past week, I also spent time on two grass-based livestock farms. The owners of these particular operations didn’t seem quite as stressed out over the state of their land during yet another wet spring — the grass was flourishing and the deep roots of these perennials were soaking up even the heavier downpours pretty nicely.
And oh yeah, these pastures were doing all this while producing beef and milk profitably — today. That seems a less risky option than waiting all summer to see if a ticked-off Mother Nature is going to stop throwing curve balls long enough to allow a fall harvest to come in.