Violence in the Atmosphere
Is the earth getting warmer or is it cooling down? Why does there seem to be more extreme weather events these days?
Whether you subscribe to the theory that climate change is caused by human activity or that it is just part of the earth’s constantly evolving weather patterns, you can’t deny that changing weather patterns have played havoc within the U.S. agricultural community.
Yet the mere mention of climate change can be both provocative and divisive in raising this very question.
I recently sat down for a round table discussion with Phil Nolte and Juliet Marshall on the long-term projections for agriculture, specifically potatoes and grains, during the next 30 years and the potential repercussions of climate change on agriculture.
Nolte is a seed potato pathologist with the University of Idaho Extension in Idaho Falls and Marshall is a cereal agronomist and pathologist and an associate professor with the University of Idaho in Idaho Falls.
Spudman: Let’s begin by discussing the warming trends we’ve been seeing.
Nolte: You speak about the negative things but I don’t know that this particular area, this Upper Snake Rive Plain area that we’re in right now, that the warming of the climate wouldn’t necessarily hurt the ability to produce crops. It would lengthen the season so you could probably get higher yields than you’re getting right now because you’ve got more time.
Marshall: We have such wonderful cool nights for potatoes, especially, and for sugar beets. Cool nights are what make the potato and the sugar beet and that’s where the greatest change is actually coming from in the temperature of the nights. The nighttime temperatures, the lows are actually increasing, more than, say, the daytime highs are increasing and that is still happening but nighttime highs increasing is a huge impact on cereals and potatoes. Cereals like it cool.
Nolte: Potatoes like the differential, like a 30-degree difference between day and night. That’s why you can grow them in the Columbia Basin where they’ll frequently have 100° temperatures during the day and it drops to 70°.
Marshall: Grains like the same bounce. They don’t like it too hot during the day; that’s why they mature quickly and more harvesting (takes place) during July and August. So the fact that our growing seasons are lengthening could be viewed as good. However, what people don’t seem to understand is the complexity of the climate change and the increased variability associated with weather events. So (there is) colder cold, hotter hot, drier dry and increased energy in the atmosphere, which creates hail and violent storms.
Nolte: Violence, and also juxtaposed with periods of higher precipitation and lower precipitation.
Marshall: That’s what people have a harder time grasping. It’s not only the climate change, it’s the overall averages that we’re facing, it’s the increasing in the variability. We have had more hailstorms, more violent storms and people don’t necessarily associate that with climate change. They just don’t seem to get that the variability is increasing. It’s difficult to breed for all these environmental changes but the other changes that we can talk about are the pathogens and the insects.
Nolte: Look at psyllids: not unheard of or unknown prior to the zebra chip experience of about four years ago, but all of a sudden, not only do we have large enough numbers of psyllids to be a concern but we have the disease itself that comes in.
Marshall: The Intergovernmental Panel for Climate Change was talking about up to three times, four times the amount of insecticides, pesticides, fungicides but potato psyllid is a good example. If you’re talking about growers who never have to spray any fungicides or insecticides or just once in a while, suddenly they’re looking at two to three to four times in a year they’re spraying insecticides to control the pests. Then you’re going to end up having three to four times the amount of environmental impacts associated with pesticide use and fungicide use.
Spudman: What kind of bugs would we be seeing?
Nolte: Any of these organisms that can’t survive the harsh winters. If we get milder conditions, gradually milder conditions, you’ll have more cases where they’ll overwinter. Right now for instance there has been some potato tuber moth in the Columbia Basin. It hasn’t become a runaway issue as yet because things haven’t got all that warm. They’ve even found some of the insects over in western Idaho. They haven’t’ found anything infesting potatoes but they’ve found the insects over there.
Spudman: Are the pathogens able to evolve faster?
Nolte: Oh, yes.
Marshall: If I remember this correctly from Biology 101, every time you increase the temperature one-degree you increase biological activity, chemical activity 10 times. So when you think about that, an insect can reproduce faster and evolve faster. Numbers increase rapidly, they come into the environment sooner. So you’re facing increasing pests, increasing diversity of pests and you’re also facing earlier pesticide applications so you’re potentially changing your whole management schemes.
Nolte: Yes, things you never had to worry about before. The people here (Idaho) are lulled into a false sense of security. They’re used to the weather behaving in a certain way that allows them to produce their crops. We generally have lower pest pressures out here than they do in other parts of the world, especially for potatoes (spraying seven times for late blight out here like they do in Michigan and Wisconsin). All of the diseases are favored by wetter conditions but then warmer temperatures also increase the ability for disease to overwinter.
Spudman: Let’s talk about food security.
Nolte: Food security on this planet isn’t nearly as good as most people think it is.
Marshall: Absolutely. I agree. The federal government is going to have to get used to more federal subsidies of crop insurance, not less. We have to get to the point where we can economically sustain these growers when they take these environmental hits every couple of years.
Nolte: How often can you take a hit as a grower and come back?
Marshall: You can’t, and so that’s going to be a major player. The federal government is going to have to get more involved as far as insurance and sustainability, not less.
