~BW Uzelman

The Intergovernmental Panel on Climate Change, in March, published a summary of their studies on climate change over the last five years. It is a disquieting read. The IPCC warns, 鈥淭here is a rapidly closing window of opportunity to secure a livable and sustainable future for us all.鈥�

Most Canadians acknowledge human driven climate change. Some dismiss it. A 2022 Leger poll showed that 68% of Canadians believe that climate change is caused by human activity. 21% said climate change is part of a natural cycle. The deniers are a small, but significant, minority.

For the IPCC there is no doubt. Their report asserts, 鈥淗uman activities, principally through emissions of greenhouse gases, have unequivocally caused global warming, with global surface temperature having reached 1.1 degrees C above 1850-1900 in 2011-2020.鈥� The panel says continued GHG emissions mean the 鈥渂est estimate鈥� is for temperature increase to reach 1.5 degrees C in the near term (2021-2040). With current climate policies, the report projects temperatures will rise 3.2 degrees by the end of the century. To limit the increase to the target of 1.5 degrees or less, 2019 emissions must be reduced by 43% by 2030 and by 60% by 2035.

The IPCC report advises that 鈥渨idespread and rapid changes鈥� are now occurring in the atmosphere and ocean. 鈥淗uman-caused climate change is already affecting many weather and climate extremes in every region across the globe.鈥� Changes are increasingly evident, it says, and include heavy precipitation, heat waves, droughts and cyclones. These events have exposed millions of people to increased food and water insecurity, the report finds, as well as increased property damage and loss of human life.

It is not necessary to look far to find evidence of extreme weather events. British Columbia was enveloped by a massive heat dome in 2021. 59 temperature records were broken in the province on June 28 alone. On June 29, Lytton set an all-time temperature record for Canada at 49.7 degrees. 27 researchers from the World Weather Attribution Initiative, after examining the data and modelling, concluded the heat wave, 鈥渨as virtually impossible without human-caused climate change.鈥�

The provincial coroner鈥檚 service attributed 619 heat related deaths to the event. 234 died just on June 29. Sarah Henderson, scientific director of the BC Centre for Disease Control, called the heat dome 鈥渢he most deadly weather event in Canadian history.鈥� Then, in November of 2021, an atmospheric river inundated the province. Rain of 200-300 mm (8-12 inches) was recorded in some areas. Flooding was extensive and severe. The Insurance Bureau of Canada later estimated insured damage at $675 million, and uninsured damage into the billions. 100 miles of highway were destroyed.

Climate impacts on BC鈥檚 wine and grape industry, located largely in the Okanagan, are undeniable. The grape harvest in BC from 2018 to 2021, 鈥渉as fallen precipitously鈥�, noted a study by Cascadia Partners. The study, prepared for BC鈥檚 Ministry of Agriculture, found crop yields declined by 33% over the period. Cascadia showed that crop yields followed similar patterns in all west coast jurisdictions. In Oregon and California yields peaked in 2018, in Washington in 2016, then declined, just as in BC. However, over the same period, Ontario yields have risen. This suggested, says Cascadia, that climate is the culprit.

Cascadia conducted statistical analysis to confirm their hypothesis. They found three climate conditions had a 鈥渓arge negative impact鈥� on yields: increases in extreme heat, increases in extreme cold and lower levels of precipitation. Extreme cold, again in December, 2022, caused major damage to the grape vines. Grape Growers BC predict the harvest will be down yet again in 2023, this time hugely, from 39% to 56%.

A University of California study examined the last 66 million years of earth鈥檚 history. It revealed four distinct climate states that it labelled hothouse, warmhouse, coolhouse and icehouse. Each of these states endured for millions or tens of millions of years. Within them are shorter cycles of climate variation responsive to orbital variations, leading to relatively small changes in temperature.

The authors showed major transitions between climate states were associated with changes in greenhouse gas levels. Coauthor James Zachos commented, 鈥淭he climate can become unstable when it鈥檚 nearing one of these transitions 鈥�.鈥� Notice that both of these findings describe present climate conditions accurately.

The study says for most of the last 3 million years the climate has been in an icehouse state, featuring alternating glacial and interglacial periods. In 1950, the authors note, temperatures began to increase. Zachos stated, 鈥淭he IPCC projections for 2300 in the 鈥榖usiness as usual鈥� scenario will potentially bring global temperature to a level not seen in 50 million years.鈥� The study relates this period with the hothouse state. It is clear, without further constraints on carbon emissions, climate change has only just begun.

bruce

Bruce W Uzelman

I grew up in Paradise Hill, a village in Northwestern Saskatchewan. I come from a large family. My parents instilled good values, but yet afforded us, my seven siblings and I, much freedom to do the things we wished to do. I spent my early years exploring the hills and forests and fields surrounding the village, a great way to come of age.

I attended the University of Saskatchewan in Saskatoon. I considered studying journalism at one point, but did not ultimately pursue that. However, I obtained a Bachelor of Arts, Advanced with majors in Economics and Political Science in 1982.

Contact: urbangeneral@shaw.ca

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