The severity and extent of droughts in the Prairies could intensify as the climate changes

CBC Alberta and Saskatchewan have teamed up for a new pilot series on weather and climate change in the Prairies. Meteorologist Christy Climenhaga will bring her expert voice to the conversation to help explain weather phenomena and climate change and their impact on daily life.

Climate change will profoundly affect our water supply as summers become hotter and winters shorter.

While precipitation is expected to increase overall, the duration and severity of droughts will also increase.

The good news is that over the past century our ability to cope with drought conditions has improved. Crop types, tillage, and even the timing of fertilizer application can help plants get the moisture they need.

What is a drought?

The Prairies are considered to be in the midst of a severe drought, although the definition of a drought is not precise.

“It’s just when you get a long period of below normal precipitation, and that has some impact on human or environmental needs,” says Barrie Bonsal, a research scientist with Environment and Climate Change Canada.

The longer the dry conditions last, the worse things get.

What increasing drought will look like on the Prairies

As the climate continues to warm, the Prairies will see both more and less precipitation. CBC meteorologist Christy Climenhaga explains. 0:59

Droughts go through phases, says Bonsal. They start out as weather droughts, like hot, dry weather, but can have a much bigger impact.

“Generally, if it’s dry during the summer and at critical times for agriculture, it will turn into an agricultural drought and we’ll start to see soil moisture deficits,” he says.

“Once we start to see the impacts on society, these droughts become socio-economic droughts and, as you can imagine, the longer a drought lasts, the harder it is to reverse it.”

Droughts are getting worse

As we continue to warm and experience greater variability in our climate, the risk of longer and more severe droughts increases.

While we’re likely to see more precipitation overall, the nature of the precipitation will be different, with more precipitation in winter or spring or in short bursts with larger storms, according to Canada in a Changing Climate: Weather Report. regional outlook.

“When we get water it can come all at once, unlike what we’ve had nice mild storms that will come over two or three days and really soak the ground that needs it,” says bonsai.

In winter, we can expect more rain instead of snow.

Snow loss, which replenishes soils in the spring, will be critical.

Despite snowy winters like this, the snowpack is shrinking, says John Pomeroy, professor and Canada Research Chair in Water Resources and Climate Change at the University of Saskatchewan.

“Snowfall as a percentage of total precipitation is down from about one-third to one-fifth of the total in many parts of the prairies now,” Pomeroy said.

And while the mid-winter rains might seem like a nice break from cold weather, they do cause other moisture issues.

“That water seeps in and freezes again on top of the frozen ground and can seal it up,” Pomeroy says. “This creates a restricted infiltration capacity, as we call it. So very little water can penetrate the soil.”

Worst recent drought in 60 years

Not every year will be a drought year, however, because droughts are cyclical, Bonsal says.

“These cycles, you know, they’re going to continue,” he said. “But the nature and character of these cycles have great potential to change with global warming.”

The area affected by last summer’s drought was the largest we’ve seen, says Trevor Hadwen, an agroclimate specialist with Agriculture and Agri-Food Canada.

“The drought that we just went through in 2021, it was as severe and as extensive as in 1961.

“Many of us remember the 2001-2002 drought and the 1988-1989 drought as recent extreme droughts. The one we just experienced far exceeds those,” Hadwen says.

Going back even further, the geographic extent of this drought puts the dirty 30s to shame, Pomeroy says.

“The drought of the 1930s was uneven. At that time, farmers could go up to northern Saskatchewan or settle in the Peace River District and find adequate moisture conditions,” he says.

In this recent drought, that would not be possible, he says.

“Last summer, almost the entire prairie region was at one point below 40% soil moisture,” Pomeroy says. “And during the growing season, almost everywhere was prone to drought, even as far as the Peace River district of Alberta.”

2021 wasn’t just a year of drought on the Prairies, it was one more year in the mega-drought plaguing the American West, which is experiencing the driest conditions in 1,200 years. Above, a kayaker paddles Lake Oroville in California in August 2021. (Ethan Swope/Associated Press)

And while the current winter has brought with it some much-needed snow, the drought continues in parts of Western Canada.

“The snowpack, at least in eastern, central and northern Saskatchewan, looks very, very good,” Pomeroy said.

“Unfortunately, they’re not good in southern Alberta and the southwestern tip of Saskatchewan, where they won’t alleviate this drought at all.”

What can be done?

Fortunately, we have seen improvements in drought management over the past 100 years.

“We have much better crop varieties in terms of their ability to survive dry conditions and extract moisture from soils,” Pomeroy says. “And we have better tillage systems and others to control dust storms.”

Minimum tillage is effective and has been widely adopted in Saskatchewan, but Pomeroy says it could be used more in Alberta and Manitoba.

“It is very useful because the development of the cracks allows all the rains, even heavy rains, to penetrate the soils.

Leaving fields stubble and reintroducing windbreaks will help reduce the effects of wind-driven snow loss, Pomeroy says.

New farming practices will be needed as drought conditions worsen due to climate change. (Richard Agecoutay/CBC News)

Research is ongoing to develop management practices for farms to support optimal nutrient and water use efficiency.

“There are sustainable fertilizer management practices — many of which are currently used on prairie farms — such as placing fertilizer in the soil at planting time, which promotes proper use of that fertilizer and water because it is absorbed by the plant. says Blake Weiseth, PhD student at the University of Saskatchewan.

Weiseth hopes that further research on melting snowpack will help farmers in the field.

“I think they can potentially be used in all of these situations, perhaps targeting their use in certain areas of the field that are particularly at risk of being affected by sub-optimal moisture conditions at either end of the spectrum.”

Our planet is changing. Our journalism too. This story is part of a CBC News initiative called Our changing planet to show and explain the effects of climate change and what is being done to address them.