Nova Scotia: Four missing after extreme rainfall hits Canada

Three months of rain fell in just 24 hours in some areas.

The flooding is the latest extreme weather event to hit northeast Canada - recent wildfires have burnt a record area, sending clouds of smoke south into the US.

There has also been extreme flooding in the US this month. The body of a two-year-old girl found along a river in Pennsylvania is believed to be one of two missing children swept away by flash floods last weekend. Her nine-month-old brother is still missing.

Scientists cannot say for certain that such extreme rainfall is caused by climate change, but the floods are consistent with the changes they expect in a warming world. This is because the warmer the earth becomes the more moisture the atmosphere can hold. This results in more droplets and heavier rainfall, sometimes in a shorter space of time and over a smaller area.