Climate change

Can we blame climate change for BC’s “atmospheric river”?


We cannot say for sure that climate change caused the heavy rains and severe flooding and landslides currently plaguing British Columbia, but global warming makes such disasters more likely, a Swiss speaker suggested Thursday. D.

“Warmer air can carry more moisture, so there is generally this notion that the frequency of heavy precipitation events – essentially in most parts of the world – would increase” due to global warming, said Andreas Weigel , head of meteorological risks at Swiss Re, during a CatIQ Connect panel.

Moderator Kimberly Roberts, Senior Vice President at Guy Carpenter, asked the panelists how they think climate change is affecting specific perils that are most important to Canada.

With global warming, temperatures are rising, so one would think winters might get milder and heat waves might get warmer, Weigel said.

“If you look at the German floods, [past] summer – and the atmospheric river that occurred in Canada earlier – we cannot say that it is about climate change, but we can say that climate change makes such events more likely. “Weigel said during the noon panel, titled Secondary Hazard Problems and Solutions: Data, Monitoring and Modeling.

Weigel was referring to a disaster that Aon said caused total economic losses of US $ 25 billion last July. The extreme rainfall in July 2021 resulted in the costliest European flooding on record, Aon said last July in his recap of global disasters. Among the hardest hit regions were the German states of Nordrhein-Westfalen and Rheinland-Pfalz, with an official death toll of 197.

On the west coast of Canada, there have been 12 evacuation orders involving 350 homes from Boston Bar to Abbotsford, British Columbia, The Canadian Press reported Thursday.

As of Thursday, flood warnings have been in effect for the Coquihalla and Chilliwack rivers as well as the tributaries of the Lower Fraser and the Tulameen, Similkameen, Coldwater and Lower Nicola rivers.

Southern and coastal British Columbia has entered the latest wave of severe weather that meteorologists have described as a “parade” of storms, CP reported.

A report published last August concludes that greenhouse gas emissions from human activities have been responsible for about 1.1 ° C of warming since the period 1850 to 1900. On average over the next 20 years, the global temperature is expected to reach or exceed 1.5 ° C. C of warming since this period, according to Climate change 2021: the basis of physical science, published by a working group of the Intergovernmental Panel on Climate Change. The working group describes a number of implications for North America, including a change in precipitation regimes, with more intense precipitation and associated flooding, particularly for eastern North America, as well as more severe droughts in many areas.

At best, there will be a worldwide sea level rise of 0.28 meters, the IPCC said in the report.

This means that we can conclude that the risk of storm surge in low areas would increase, Weigel said Thursday during CatIQ Connect, produced by Catastrophe Indices and Quantification Inc.

Also on the panel was Tom Larsen, Director of Industrial Solutions at CoreLogic.

“Climate is different from weather because weather volatility is what our customers are dealing with right now – bad years and good years,” Larsen said.

The modeling of severe convective storm systems is complex. With a severe convection storm, hundreds of tornadoes and hundreds of square kilometers could be affected, Larsen said.

Currently, unlike the hurricane, the industry does not have an intensity scale for a severe convection storm, Larsen noted.