The report, prepared for the parks and environment committee, says incidents of extreme weather will occur more often as global warming upsets normal weather patterns.
It's the first real attempt to gauge what effect climate change might have.
The report paints a troubling picture of the year 2040.
In 30 years, the report predicts average temperatures will jump by 4.4 degrees — resulting in storms with twice the rainfall and four times the number of heat waves.
It says that will be too much for the city's aging roads, sewers, and storm drains to handle.
"I think what we need to do is make sure our infrastructure is ready to accommodate these higher temperatures, and high volumes of water," said Lawson Oates of the environment office.
But that kind of infrastructure overhaul would cost billions — money the city doesn't appear to have.
The city paid for the climate change study after a devastating rainstorm in 2005 wiped out a stretch of Finch Avenue West, costing hundreds of millions to repair.
The report also points to other extreme weather events in Toronto — from last summer's record heat, to record rain storms — and the resulting costs.
The committee received the report and voted to create a working group to study the study.Suggest a correction