Federal payments to the provinces for disaster relief have skyrocketed over the past five years because of the increasing number of extreme weather events.

The liabilities have “increased substantially because of a number of weather events that have caused heavy damage,” says a new report released Thursday from the Office of the Parliamentary Budget Officer (PBO).

As a result of the increased frequency of the storms, the federal Disaster Financial Assistance Arrangements’ (DFFA) transfers to the provinces have been much higher than its annual $100-million allocation.

The report shows payments from the DFFA ballooning because of the sheer number of extreme weather events and related disasters.

According to the report, in the fiscal year 2012-2013, DFAA transferred $280 million to the provinces; by 2013-2014, this had increased to $1.02 billion and $305 million in 2014- 2015.

The PBO estimates that between 2016 and 2021-22, payments can be expected annually to reach $229 million because of hurricanes, and winter storms. It is expected flooding will cost the DFFA program another $673 million over the five year period.

Besides the increasing number of large storms with greater intensity, the PBO cited four events over the last four years that ratcheted up the cost of the payments.

They were the heavy rains in June 2014 in Saskatchewan, which is expected to cost the program $160-million; the Toronto ice storm of December 2013, which is anticipated to cost $120 million; and the Southern Alberta and southeastern B.C. flood of June 2013, which an expected cost of $1.3 billion.

The fourth event was the flooding of the Assiniboine River in Manitoba in 2011. The program is expected to pay out $524 million to Manitoba and another $245 million to Saskatchewan.

The report only mentions climate change in passing, and the reference is buried down near the bottom of the document.

“One last factor, which is likely affecting the intensity of floods in the Prairie Provinces, is climate change,” notes the report.

“The warming in the arctic has been associated with persistent weather systems in the mid-latitudes as well as extreme weather events. Consistent with this, multiple-day rain events have significantly increased in the Prairie Provinces and in the Rockies.”