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Climate change and your farm

In this three-part series on climate change, Angela Lovell takes a look at 
what our Prairie farms might look like in 30 years

This is the first in a three-part series on how climate change might impact agriculture on the Canadian Prairies.

If, as climate scientists predict, Canada’s Prairie region is significantly warmer in 30 years than it is now, the farm could have a very different mix of crops and livestock, some new agronomic practices, a few new challenges and expanded economic opportunities.

It’s very likely that farmers will be growing more warm season crops, such as corn and soybeans and fewer cool season crops such as canola. In areas where crops currently rely heavily on irrigation, tightening groundwater supplies will necessitate a switch to crops that are naturally more heat tolerant and water use efficient.

Livestock producers could have more upland cattle breeds such as Dexter or Highland, which are better adapted to convert low quality forages, and some sheep or goats grazing with them to help maintain the species diversity of the forage and pastureland.

There will almost certainly be some new weeds, insects and diseases to deal with, which have moved their range northwards, as well as some familiar ones, some of which have become resistant to existing pesticides and have better survivability than they used to, thanks to earlier springs, longer falls and milder winters.

Challenges caused by more frequent droughts, heat waves and/or floods in other major agricultural regions such as the southern U.S., Russia, South America and Europe, could ramp up demand for crops produced in the longer growing season of the Canadian Prairies. Market opportunities and prices could increase and provide better returns, as long as Mother Nature doesn’t hit the Prairies with one of her much more intense and frequent extreme weather events.

How likely is this scenario?

Researchers at Simon Fraser University (SFU) and the University of Concordia recently published a research report which concludes Canada’s climate will inevitably warm by a least two degrees over the next decade, and that’s if all greenhouse gas (GHG) emissions ceased today. Due to GHG emissions to date the world’s temperature has already warmed by 1.5 C since the beginning of the industrial era. The study shows that eliminating all emissions would still lead to an additional short-term warming over the next decade of 0.25 to 0.5 C because of the concentration of long-lived GHG’s such as carbon dioxide already present in the atmosphere.

“One to 1.5 C of global warming may not seem like a great deal,” says report co-author, Dr. Kirsten Zickfeld, an assistant professor of geography at SFU in a press release from March 2012. “But we need to realize that the warming would not be distributed equally over the globe, with mid- to high-latitude regions such as Canada, Alaska, northeastern Europe, Russia and northern China being most strongly affected. Our research shows that as a result of past emissions, a warming of at least 2 C will be unavoidable in those regions.”

Two degrees may seem pretty insignificant, but to put it in perspective, Zickfeld adds, the global temperature was only five degrees colder than today’s during the last ice age.

The above scenario does not venture into the realm of GHG emissions continuing to rise at current rates, which is a much more likely scenario, and which is leading many scientists to predict increases in overall global temperatures anywhere in the range of 2.5 C to 6 C degrees by 2100. There’s no quick fix to the problem of climate change. Thirty-three per cent of all fossil fuel carbon dioxide emissions remain in the air after 100 years and 19 per cent are still there after 1,000 years.

When you add in the multiplier effects of other feedback processes (such as melting polar ice caps and rises in global mean sea level), it’s almost impossible to predict the extent to which localized weather patterns in many areas will be affected by climate change and in what way they will be affected.

Because plant and animal responses are so dependent upon temperature, water availability and carbon dioxide concentrations, and these will vary widely across the planet, it’s also hard to predict the agricultural impacts of climate change. Some areas are likely to see increased crop yields and others will see them fall. What is grown will change as drought, temperature shifts and water availability define the areas where certain crops can be grown and the areas where they cannot.

Extensive research and review of scientific literature to date has led Dr. David Lobell and Sharon M. Gourdji of Stanford University to conclude that global warming from 1981 to 2002 has likely already had a negative impact on some crop yields worldwide, but that impact has been more than compensated for by technological advances and increases in carbon dioxide concentrations, which overall have increased yields and masked the effect of rising temperatures.

“The results from a global-scale study, which estimated impacts for the 1980-2008 period,” say Lobell & Gourdji in their 2011 paper, The influence of climate change on global crop productivity, “[indicate that] warming trends were estimated to have lowered wheat and maize yields by roughly six and four per cent, respectively, over the 29 year period, with relatively small impacts of [precipitation] trends. Global soybean and rice yields were deemed to be relatively unaffected by changes so far. Yields for barley, maize, and wheat all increased substantially since 1980, but not as much as they would have if climate had remained stable.”

The Prairies already have one of the world’s most variable climates, which has, on occasion, had significant economic impacts. It is estimated that the drought of 2001-02 caused an approximate $3.6 billion drop in agricultural production.

In its 2008 report, From Impacts to Adaptation: Canada in a Changing Climate, Natural Resources Canada predicts that climate change in the Prairie region will result in increased water scarcity, greater frequency of dry years, more land and aquatic invasive species, new pests and diseases and more frequent extreme weather events bringing increased precipitation and flooding. “Extreme events, and an expanded range of year-to-year departures from climate norms, represent greater risks to the economy of the Prairies than a simple shift in mean conditions,” says the report.

In the next instalment: How increasing carbon dioxide could have a positive (but short timer) impact on the growth of plants — and weeds. †

About the author

Contributor

Angela Lovell

Angela Lovell is a freelance writer based in Manitou, Manitoba. Visit her website at http://alovell.ca or follow her on Twitter @angelalovell10.

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