Our new reality in data form: More windy days, fewer cold days, more hot days on P.E.I.
'Climate change is with us,' says the director of the UPEI Climate Lab
Climate change is already happening on Prince Edward Island, and it's having an impact on how Islanders live and work every day.
Climate scientists warn that if humans' behaviours don't change, the global average temperature could rise by 2 C above pre-industrial levels in the 2060s, and this could bring catastrophic and irreversible consequences.
We are already almost halfway there. From 1880 to 2012, the global average temperature rose 0.85 C.
This increase is melting glaciers in the Arctic and leading to more frequent wildfires in western North America, among other impacts.
But from the perspective of a Prince Edward Islander in 2020, these predictions and even the current conditions can be difficult to see. In this special series, CBC News will look at how climate change has already made a difference to the weather on the Island, and how Islanders are already having to adapt.
A warmer Island
At Environment Canada, the gold standard for measuring climate is the 30-year average.
When a weather forecaster tells you the temperature will be near normal today, that's in comparison to an average of temperatures recorded on that particular date on the calendar over the course of 30 years. The average is updated every decade, so the current average refers to the 1981-2010 span.
That average has changed over the past 50 years on Prince Edward Island.
The most recent climate normals used by Environment Canada places the average maximum daily temperature in July at 23.3 C. The climate normals for 1951-80 listed the average as 23.0 C.
It doesn't seem like a big difference, but there's another way of looking at this that is a little easier to relate to. There are more hot days now than there were in previous decades. There are also fewer cold days -- and, as it turns out, more windy days.
"A significant shift like that is something to pay attention to," said Adam Fenech, director of the UPEI Climate Lab.
"For the last 32 years, scientists have been saying this is exactly what we'd anticipate. So it's just further evidence that climate change is with us."
As we can see in the 30-year averages, the number of hot days on the Island — defined as days when the temperature rose past 25 C — jumped by almost 20 per cent in the most recent 30-year period.
This trend seems to be accelerating.
Since 2014, every single year has seen 30 or more hot days. That's seven years in a row, whereas in the previous 59 years, there had been just 15 such years.
This chart compares the most recent seven years to seven-year periods going back to 1955.
While it is clear that the temperature goes in cycles — there was a jump in the 1960s and in the 1990s — the most recent increase exceeds the amount tracked during those cycles. In addition, the dip in the graph in the early years of this century is not as deep as the ones in the 1950s and 1970s.
Seven years is not enough to confirm a climate trend, says Fenech, but it is enough to be concerned about.
"Normally, for any trend analysis, we do need 30 years of data," he said.
"We don't have the luxury of that with the major changes that are occurring right now. But certainly, when you see these major jumps or shifts like this, you can certainly see that's where the trends are going."
Out of the deep freeze
The trend in the number of officially defined cold days, days on which the temperature goes no higher than -10 C, shows a similar pattern.
When you compare the number of cold days in the 1951-80 average, you find almost 20 per cent more than in the 1981-2010 average.
The number of cold days varies widely from year to year. Since 2014, there have been as many as 17 cold days in 2015 and as few as just one in 2016.
But the seven-year averages show an even stronger trend than the one for formally defined hot days. That average fell below 10 in 1995-2001 and has not risen above it since. Going back to 1955, there were only four other seven-year periods where the average was below 10 days.
Another change: Recent years on P.E.I. have seen more officially defined windy days — days featuring gusts over 50 km/h — than most Islanders would remember from past decades.
As with hot days, the number of windy days runs in cycles.
While the 30-year averages for wind do not show a change as large as the ones for cold and hot days, like those trends, the rate of change does seem to be accelerating.
The most recent dip, in the early years of the 21st century, did not go as low as the previous drop in the 1980s.
From 2001 to 2012, there were no years with more than 90 windy days. In 2013, there were 91 days, and since 2014 it has been triple digits every year.
Of the three trends, wind is the most volatile.
For example, this chart shows a spike in the 1990s, but this is mostly the result of a single, spectacularly windy year. In 1996, there were 231 windy days. No other year since 1955 before the current windy period had more than 138 days.
This is not the first time in the recent record that the Charlottetown Airport had a long stretch with more than 100 windy days per year. It last happened from 1960-68, which is longer than the current streak.
The last seven years, however, were windier than any seven-year-stretch in the 1960s.
As of mid-November, 2020, there had been 101 windy days, bringing the recent stretch of triple-digit years to eight.
All three of these — more heat, less cold, more wind — are changing the way Islanders work and live. In the coming days we'll look at how.
Climate change now on P.E.I.
The pieces in this four-part series:
- Monday, Dec. 28: Our new reality in data form: More windy days, fewer cold days, more hot days on P.E.I.
- Tuesday, Dec. 29: How daily work is changing on P.E.I. as wind and temperature patterns shift
- Wednesday, Dec. 30: On the beach: Changes in weather patterns affect creatures big and small
- Thursday, Dec. 31: How P.E.I.'s farming and fishing industries are adapting to the new normal