The current magnitude of Australia's floods are likely to be the result of climate change, say some scientists, though the evidence is not entirely clear yet.
"The waters off Australia are the warmest ever measured and those waters provide moisture to the atmosphere for the Queensland and northern Australia monsoon," Matthew England of the Climate Change Research Center at the University of New South Wales, Sydney, told Reuters.
"It has to be affecting the climate, regionally and globally. It has to be affecting things like La Nina. But can you find a credible argument which says it's made it worse? I can't at the moment," president of the Australian Meteorological and Oceanographic Society, Neville Nicholls, countered.
El Nino is a warming of waters in the Pacific and often reduces rainfall and leads to drought, while La Nina is the opposite--an extreme cooling of the Pacific waters, which triggers strong winds, rain, cyclones, and ultimately floods. The intensity of the two fluctuate, which has led to notable storms in the past, while other times leaving no significant imprint.
But this year the rains are not expected to end anytime soon--Indonesia has already said that rains will last until at least the summer.
So what about the role of human interaction with the environment? El Nino and La Nina are not, after all, the products of man-made influence--they're natural occurrences, so if a particularly bad El Nino or La Nina occur and cause floods, who's to say that humans had anything to do with that?
"The first thing we can say with La Nina and El Nino is it is now happening in a hotter world," said David Jones of the Australia Bureau of Meteorology in Melbourne in the Reuters report. So the question begging an answer is whether humans are the ones who made the world hotter and if that increase in temperature ultimately exacerbates floods.
"I think people will end up concluding that at least some of the intensity of the monsoon in Queensland can be attributed to climate change," said England.