Let’s stop to list some of the recent extreme weather events in Australia:

· Serious and long-lasting floods in Queensland around Rockhampton.

· Unprecedented flash flooding in Toowoomba and the Lockyer Valley.

· The biggest floods on record in western Victoria.

· A 100-year record flood in Brisbane.

· The warmest spring on record in Perth.

· Sydney has just had a record heatwave, including its hottest February night on record.

· South Australia and western Queensland had a severe heatwave in late January.

· And, of course, severe tropical Cyclone Yasi, the worst cyclone in living memory in northern Australia.

The impacts of these events spread beyond the obvious destruction of homes and lives that was widely reported in the media.

For example, the wet weather has brought plagues of mosquitoes, with a huge rise in mosquito-borne diseases like Ross River Fever and Barmah Forest Virus. Crops have been destroyed in many areas. Food prices are tipped to rise even higher.

Behind many of these phenomena is a record La Nina weather event, which the Bureau of Meteorology (BOM) says is the strongest since 1917.

BOM’s Darren Ray told the ABC on February 10: “There's an argument there that these record warmest ocean temperatures have at least contributed to increasing the intensity of both the flooding and the tropical cyclone activity that we're seeing in the last few months.”

Australia hasn’t been alone. The past year has seen big snowfalls in the US and Europe, severe drought in the Amazon, and severe flooding from South Africa and Sri Lanka, to the Philippines and Brazil (among others).

Despite the cold weather in Europe and North America, 2010 was the hottest year on record.

After observing a terrible event like cyclone Yasi it would be easy to conclude that climate change is real. But by that logic, a cold winter proves that climate change is not occurring.

There is a difference between weather and climate: individual weather events have a very complicated set of causes.

No measuring equipment is available that can separate all these causes to determine how much a single weather event was caused by climate change.

“Climate is the statistics of weather over the long term,” Ken Caldeira, a senior scientist at the Carnegie Institute for Science at Stanford University, told MSNBC’s LiveScience on February 2.

“No specific weather event can by itself confirm or disprove the body of scientific knowledge associated with climate change.”

If no single weather event can be directly attributed to climate change, does that make climate change a fiction? That would be as logical as taking literally the saying “tomorrow never comes”.

Warmer temperatures mean greater evaporation, and more water vapour carried in the air.

This can contribute to drier conditions over land, exacerbating droughts.

It also can increase the amount of rain or snow when that extra water vapour does finally precipitate, leading to greater floods and snowstorms.

And warmer ocean surface temperatures increase the intensity of cyclones.

The bunch of extreme events we have seen this year certainly fit the pattern of a warming climate: they are evidence that supports the case for global warming.

Climate scientists have forecast more unpredictable and extreme weather just as we are seeing. If climate deniers scream “there’s no proof!” they only prove their own ignorance.

The federal government has backed a levy to pay for rebuilding after the Queensland floods. While the federal opposition has been criticised for opposing the flood levy for its own selfish political ends, there is genuine opposition to a flood levy from other quarters.

Independent MP Rob Oakeshott has questioned whether defence budget cuts might instead help pay the bill.

He said on ABC’s Radio National on February 10: “Many people have put to me in emails for example, if we got one less JSF [Joint Strike Fighter] that's $110 million right there.”

The Federal government has instead cut climate change-related programs to pay for flood damages.

Melbourne group Yarra Climate Action Now said on January 30: “The Solar Energy Society has estimated that $495 million will be cut from solar energy programs…

“The irony here is inescapable. Ever-worsening and more frequent natural disasters are directly linked to human greenhouse gas emissions.

“Yet while the federal government continues subsidising fossil fuels — the cause of the problem — to the tune of billions of dollars per year, it cuts funding to the solutions — renewable energy and energy efficiency.”

Australian Greens Senator Christine Milne said on January 27: “It beggars belief that the government would choose to cut climate change programs like Solar Flagships, energy efficiency and the solar hot water rebate to fund disaster relief when such disasters will be made worse by climate change …

“We need to start planning now for the reality of climate change and redouble our efforts to return to a safe climate, not cut back on that effort.”