It might be hard to prove either way in some cases.
Some recent events, however, are so extraordinary....
In 2015, Boston’s month of snow was a 1-in-26,315 year occurrence.Yet the amount of wintertime cold air circulating around the Northern Hemisphere is shrinking to record low levels.
Some researchers are finding that there is probably a link to climate change in some cases of extreme weather.
One scientist investigating one area of this problem is Professor Jennifer Francis.
Prof Francis is particularly interested in how the odd behaviour of the jet streams is being linked to the way the polar areas are warming faster than other parts of the Earth.
There were some very unusual weather events in 2010, which may be a warning of future effects of climate change.
China and Brazil had serious droughts, and in the first part of the year the Northern Hemisphere warmed fast, melting the winter snow cover very quickly.
The picture shows the dried-up River Negro in Brazil, with a bridge in the distance.
But the biggest events were the heatwave in Russia and the flooding in Pakistan.
In Pakistan, Government officials said that from July 28 to Aug. 3, parts of Khyber Pakhtunkhwa province recorded almost 12 feet of rainfall in one week.
The province normally averages slightly above 3 feet for an entire year.
Pakistan Floods Russian forest fire
In Russia, the heatwave went on for weeks, causing forest fires and destroying crops.
The Russian harvest was reduced in 2010, so the government stopped exports of grains.
The link between the floods and the heatwave was a blocked jet stream.