What is the link between extreme weather and climate change?

" Extreme weather events in Italy, Australia and Japan are believed by many to be linked to man-made climate change.

In the Italian alps, at least seven people have been killed after being caught in an avalanche sparked by the collapse of the Marmolada glacier.

Meanwhile, Australia's largest city Sydney saw torrential rain and flooding, in which a man died and thousands were evacuated.

At the end of June, Japan suffered its worst heatwave ever recorded which saw more than 5,000 across the country hospitalised."