Here's a two-part series that I wrote for the Low Down newspaper - my local community paper in the Gatineau Hills. Republished here with supporting visuals:
The Hills Are A-Changin’: Tracking our Hotter and Wetter Weather (Part 1)
By Ryan Katz-Rosene, October 23rd, 2023
September 2023 was a stunner for climate change scientists. The average global temperature that month was 1.8°C warmer than the typical September of the pre-industrial era, completely shattering the record which had only been set earlier this summer, in July. 1.8°C may not sound like a lot, but consider that the Earth’s average temperature during the last ice age – when most of North America was covered in a sheet of ice – was only about 5°C cooler than the pre-industrial era.
Unsurprisingly, September was warm here in the Hills too, with the average monthly temperature clocking in at 2.59°C warmer than the typical September from the mid-Twentieth Century (using a 1951-1980 baseline). But it wasn’t our warmest September ever. Remarkably, September 1961 holds the record for that month here in La Pêche (at least going back to 1940, at 3.68°C warmer than the 1951-1980 baseline).
You’ll note two important things from the above: First, localized temperature patterns are far more variable than global temperature trends. As Dr. Saravanan, Professor of Atmospheric Sciences at Texas A&M University, told me, one does need to be “very cautious in interpreting local trends, which include both human-induced warming and natural variability,” with the latter being “much stronger locally”. Second, warming here has actually been much greater on average than the global mean warming. Globally, the world has warmed on average about 1.3°C (even though this year specifically will likely surpass 1.5°C) since the pre-industrial era, but much of Canada has already warmed by 2-3°C on average (this is because land and extreme latitudes have warmed at a greater pace than the vast oceans covering Earth).
If we chart the annual average temperature change observed here in the Gatineau Hills (specifically here in La Pêche), we can see a clear trend of warming since the 1940s. The early 1950s were surprisingly warm here, and the region saw cooler temperatures through much of the 1960s and 1970s. We then saw some rather large temperature swings, with hot years bringing up the running 10-year average up by about +0.8°C relative to the 1951-1980 baseline. While in global terms 2023 is on track to be the warmest year on record, the jury is still out on whether that will also be the case locally – but the current record warm 1998 (a super El Niño year which was 2.25°C warmer than baseline locally) will be hard to beat.
The temperature changes are more pronounced when you break them up by season. Here in the hills our winters have seen greater warming than other seasons. The typical winter of the last decade was about 1.4°C warmer than the typical winter of the 1951-1980 baseline. A few anomalously warm summers in the 1940s and 50s, and warm autumns in the 1940s drove up the decadal averages earlier in this series for those seasons, but make no mistake – the clear trend is one of warming since 1940 (even though the linear trend for fall is mostly flat over the last 80 years).
What kind of warming is coming down the pike? That’s for another piece. But it is interesting to note that the world is currently transitioning from a ‘triple dip la Niña’ to at least a moderate-strength el Niño, and the last few times that’s happened have tended to be record warm in global terms. What happens here in the Hills may differ: The Weather Network is reporting that this could become a “Modoki El Niño” which starts off warm across the country but then could see bursts of intense cold here in the Eastern half of the country over the winter. Only time will tell!