More heat may increase food production. It might also accelerate plant diseases, spoilage and soil erosion. How can farmers prepare for global warming?
By Ray Ford
Beyond the wind-whipped spruces and past the chain-link fence, the tidy brick homes on London, Ontario’s Webster Street, are still firmly in 2009. But just metres away, in a field of browning grasses that rustle like paper, Hugh Henry offers me a guided tour of the future.
“People will look at this and say, ‘Hey, global warming’s not so bad. This stuff is still growing,” the University of Western Ontario biology professor says. “But I’m interested in the threshold effect. You can push the system very far and have very little happen. But if you push it past a certain point, you have a major impact.”
Henry is pushing the field toward 2050, feeding $7,000 worth of hydro every year into heat lamps that droop above the plots like sunflowers. When he switched on the power in the fall of 2006, he hiked the temperature in parts of the field by 2 C to 3 C. It was instant global warming, in the range we are likely to experience in Ontario in just 40 years, when the world is not only warmer but hungrier – and when buying whatever you want to eat, whenever you want it, is a fond memory.
That seems hard to believe in a country with a 23 percent obesity rate, where shelves are lined with exotic delicacies from around the globe and where each of us wastes an average of 183 kilograms of food a year. Most farmers feel the same way. When University of Guelph researchers interviewed producers in Ontario’s agricultural heartland, they found them “generally unaware of or, in many cases, unconcerned about the potential effects of climate change.” Global warming “doesn’t keep me up at night,” said one dairy farmer. “In the short term, I would be more concerned about interest rates.” By the time climate change affects the farm, added another, “it will be so far down the road that I will be long forgotten.”
Could a couple of degrees of warming over a few decades really change the bounty we’re accustomed to? And even if it does, is there anything we can do now to prepare?
At the close of this past summer of discontent, when near constant showers blighted tomatoes and leached the goodness from hay crops, I decided to find out. I left my own farm hard by the northwestern corner of Algonquin Provincial Park for a motorcycle trip into the future. My destination: Henry’s field and the nearby Biotron Experimental Climate Change Research Centre.
Heading south through Ontario is like putting climate change on fast-forward. As David Pearson, a Laurentian University geologist and co-chair of Ontario’s Expert Panel on Climate Change Adaptation, explains, for every degree the climate warms, it’s as if the regional climate migrates 200 to 300 kilometres north. Given that our current rate of belching greenhouse gases will warm the province by about 2 C in the summer and 3 C in the winter by 2050, summer in southern Ontario will feel more like it does today in central Ohio.
So as I ride through the granite rock cuts of Highway 11, angle southwest across the limestone near Orillia and head through the corn and soybean fields of Perth and Middlesex counties, I enter the kind of humid, sultry weather that will be a lot more common on my farm by mid-century.
Looking at these expansive barns and fertile fields, it’s easy to see warming as an advantage. In my neighbourhood and further north, grain corn will go from being a gamble to a reliable crop. How about Manitoulin Island as Ontario’s next major wine region? According to the latest report from the Intergovernmental Panel on Climate Change (IPCC), farmers in northern countries like Canada will see a net benefit. But, as with any system that relies on biology, agriculture is a complex process – one in which adding more heat does not automatically guarantee more food. More heat could also lead to more plant diseases and spoilage, or more soil erosion. Or more visits from Jeremy McNeil’s favourite subject, the armyworm.
McNeil, the scientific director of the Biotron Experimental Climate Change Research Centre in London, specializes in studying the dun-coloured moth that hitchhikes to Canada on winds from the southern United States. When the moth’s eggs hatch and the conditions are just right, regiments of larvae – armyworms – emerge to chew their way through grasses, leaving a forest of leafless stalks in their wake.
“When I started studying them in the 1980s, outbreaks came every three to 20 years,” says McNeil. In the past 15 years, however, there have already been four or five outbreaks, an intensification of the pattern. “We’re not sure why,” he says, opening an incubator the size of a walk-in closet, where thousands of worms are housed in individual containers. “Maybe the winds are more favourable. Maybe milder winters help, too. It could even be chance.”
McNeil wants to see what the worm will do in the future, because – as the mountain pine beetle has proven in British Columbia – a single pest unleashed by global warming can have a devastating effect. Cold winter nights used to keep this beetle in check. When winters warmed, the beetle population exploded, chewing through half of British Columbia’s mature pine forest.
For the armyworm and other migratory insects, the issue isn’t winter chill but timing. As autumns become warmer, will the moth head south, or will it linger only to fall prey to the first killing frost? There are similar questions about pollinators including hummingbirds, butterflies, bumblebees and mosquitoes: Will they arrive on time to pollinate plants, or will the warming encourage them to show up too soon or too late to ensure that plants produce fruit?
When the Biotron is fully operational late this year, scientists can probe these issues by staging complex simulations in its “biomes” – rooftop greenhouses where scientists can control the heat, rainfall and carbon dioxide levels and watch their impact on soils, microbes, insects and plants.
The process is not simple. “You can’t just throw the armyworm of today into a chamber that represents 2025,” says McNeil. “We’ve got to mimic the evolutionary changes the worm will be exposed to during the next 15 years.” To do that, McNeil and his students would have to breed generations of armyworms in increasingly hot environments with higher carbon dioxide levels, in an attempt to produce the type of pest farmers will battle decades from now.
By simulating the future in a greenhouse, McNeil hopes to “get the answers ahead of time,” warning farmers of the challenges they will face in a greenhouse world.
Henry’s field is another sort of early warning system. As he explains the layouts of these plots in a neglected corner of Agriculture and Agri-Food Canada’s research station in London, I study the grass and rub the earth between my fingers. If this is the future of my farm, will I be able to make a living from this ground?
I’m comfortable on my own northern clay, understand it and know how to work with it. But I am not sure what to make of this lighter London land, with its heavy layer of thatch above the earth, its crown of rank, overmature grass. It seems somehow less lively than the earth at home. Is that due to the impact of Henry’s experiment, or simply my own unfamiliarity with the soil?
But farmers are optimists. With some tender loving care (in the form of manure, more legume seed and rotational grazing), I could probably work with this soil – all else remaining equal.
The problem, as Henry reminds me, is that things are unlikely to remain equal. Along with the extra warmth from the heat lamps, he is adding nitrogen to simulate the effects of all the nitrogen-laden pollutants that will be pumping out of tailpipes, smokestacks and fertilizer and manure piles by 2050 if fossil fuel use continues to grow as expected.
In theory, all that extra heat and nitrogen should help plants thrive – an effect the IPCC is banking on when it assumes that the warming climate will make Canadian farms more productive. But some plants may thrive more than others, including what Henry calls “weedier, more aggressive” species that will take advantage of the hotter, drier, more nitrogen-rich environment. Kentucky bluegrass and smooth brome are already outgrowing some of the more nutritious clovers and trefoils in the plots.