Storm Intensity Not Increasing. Review of Weather Event Statement in Insurance Bureau of Canada’s “Telling the Weather Story” prepared by Institute for Catastrophic Loss Reduction. Environment Canada analysis and engineering dataset review for Canada and Ontario, July, 2015. "Old extremes are the new normal".
As illustrated through these slides, Telling the Weather Story makes a statement on the increased frequency of storms and weather events, indicating that in parts of Canada, events that occurred every 40 years are occurring every 6 years, due to climate change.
The statement on increased frequency is unfounded as (based on ICLR's IPCC source and material and IBC's presentation to the Empire Club of Canada) it is based on a theoretical shift in temperature frequency from a global climate change report, and is contrary to Environment Canada’s actual analysis and data on local rainfall intensity trends.
The Telling the Weather Story statement on increased storm intensity, based on temperature theory has been i) embraced as rainfall facts and research by many organizations, ii) embellished to apply to extreme rainfall, and iii) considered in policy and economic reports. Organizations promoting the misinformation in the statement include TD Economics, The Toronto Star / thestar.com, CBC News, Canadian Chamber of Commerce, Columbia Institute Centre for Civic Governance, Civic Action, CBC Doc Zone, The Calgary Sun, CanadianUnderwriter.ca, Aviva Canada, Insurance Bureau of Canada.
Due to the unfounded Telling the Weather Story Weather Story statement, policies and efforts toward mitigating increasing urban flood damages may be misdirected to climate change mitigation, as opposed to more effective risk identification/management efforts, urban planning / stormwater management policies and infrastructure remediation / capital investment efforts that address the root causes of increased damages, not related to theoretical storm frequency shifts.
It is an inconvenient truth that increases in temperature, and in theory water vapour, have not translated into increased rainfall intensities. Research at MIT and Columbia in fact states the contrary, that rainfall intensities can decrease at higher temperatures and that intensities are governed by CAPE and not temperature.
Environment Canada has been correcting false reporting by the insurance industry on this topic of increasing rainfall frequency, for example correcting CBC reporting:
Or recent reporting in Canadian Underwriter, specifically on the Weather Story: