Climate change means more 'mild days' ahead for Canada, study suggests

Research suggests climate change could increase the number of nice days with mild weather for Canadians.

'Mild days' are considered those between 18 C and 30 C, with little humidity or rainfall

Canada is expected to gain more 'mild days' due to climate change, a Princeton study suggests. They are defined as days topping out between 18 C and 30 C, with less than one millimetre of rainfall and not too much humidity. Like this day on the beach in Port Dover, Ont. (Dave Chidley/Canadian Press)

Research suggests climate change could increase the number of nice days Canadians enjoy.

Most global warming studies have focused on extreme weather or broad-scale averages of temperature and precipitation. But Karin van der Wiel, of New Jersey's Princeton University, said that's not how people will experience their new circumstances.

"If you are a person living in Canada, it's never the average climate," said van der Wiel, whose paper was published today in the journal Climatic Change.

Van der Wiel and her colleagues thought a good way to demonstrate the daily consequences of increased greenhouse gases in the air would be to calculate how many "mild days" different regions of the globe would experience — days topping out between 18 C and 30 C, with less than one millimetre of rainfall and not too much humidity.

"We looked at the actual days that feel mild," she said.

"These are the days that people can relate to — the day you had a really nice walk in the park or went to a baseball game and it was really nice."

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Canada, Europe likely to gain 'mild days'

It turns out Canada is one of the places to be.

The globe, on average, is expected to lose four days of nice weather by 2035 and 10 days by 2081. Africa, Asia and Latin America could see 15 to 50 fewer days of mild weather a year by the end of the century. Southern parts of the U.S. on the coast could lose a couple of weeks.

On average, Earth will have four fewer days of mild and mostly dry weather by 2035 and 10 fewer of them by the end of the century, scientists predict. (Karin van der Wiel/NOAA/Princeton University via Associated Press)

But Canada, along with other mid-latitude areas such as Europe, is likely to see gains of anywhere from five days to three weeks.

Scientists have long surmised the impact of climate change could be most benign for humans in those regions. Van der Wiel's study is the first to frame the issue in a way that non-climatologists can understand.

"It's really difficult to feel that what was a once-in-25-year event is now a one-in-20-year event," she said. "I think this
'mild day' that we came up with is easier to relate to."

More rain, bigger forest fires

Not that there isn't a down side. Van der Wiel's paper doesn't include a nasty day index and previous studies suggest we'll have plenty of them.

Even in Canada, expect more flooding downpours and winter rains that wash away before they can nourish crops. Forest fires, already at record levels, are likely to get bigger. Rocky Mountain glaciers, the water source for many Prairie cities, are on their way out. The southern prairies will see more drought.

An aerial view of the flooded areas along the Richelieu River in St-Jean-sur-Richelieu, Que., in May 2011. Canada can expect more extreme weather events, scientists say. (Associated Press)

Forests once harvested for timber are likely to turn into prairie. Pacific coast fisheries are predicted to decline up to 10
per cent.

The paper also points out that areas that will lose nice weather are much more heavily populated than ones that will gain some, which has implications for everything from weather-related disasters to the crops people depend on.

Still, said van der Wiel, the paper is an attempt to translate the grand abstractions of climate models and global averages into a metric that makes sense.

"We are scientists, but we are people too," she said.