By Samantha Hayes
For the first time scientists say man-made climate change is causing extreme weather events like droughts, heat waves and floods.
Nearly 400 experts from around the world produced a report with evidence human activity and an increase in greenhouse gas emissions is influencing major climate events.
2011 was the year of extreme weather according to the American Meteorological Society's state of the climate report: last year seven tornados caused $1 billion of damage in the United States, there were record floods in Brisbane and cyclone Yasi hit Queensland - Australia's most powerful tropical cyclone since World War One.
For years scientists have warned human activity is creating climate change but now for the first time they've gone further - concluding it is creating more freak weather events.
“We can’t explain these events by natural variability alone, “says climate scientist Tom Karl “They’re just too rare, too uncommon.”
The state of the climate report was compiled by nearly 400 scientists in 48 countries, including Victoria University's James Renwick.
“The risks of a lot of extremes - heavy rainfall, high temperatures and heat waves associated with that, forest fires, droughts and the risks of those things are all increasing,” says Mr Renwick.
The scientists studied 50 years of data and found last year's Texas heat wave was 20 times more likely to happen because of climate change than natural variation in weather systems, and the United Kingdom’s record warm November - the second hottest since records began in 1659 - was 60 times more likely.
Scientists have long struggled with a link between individual events and climate change but they're now sure it's boosting the odds of extreme weather.
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