Undecided: Day-to-day weather can sway opinions. Credit:Kate Geraghty The average estimate was that humans were 61.7 per cent responsible. Those who identified humans were mostly responsible (as opposed to nature) rated the human contribution at 80 per cent. But even those who said they didn't know if climate change was happening rated humans as 56 per cent responsible. And more than half of the large chunk of those surveyed who thought climate change was natural (38.8 per cent of the total) marked humans as at least 50 per cent responsible anyway. Of the 588 respondents who completed all four CSIRO surveys, more than one in four gave different answers in the first and fourth surveys. John Cook, a researcher studying the psychology of climate change at the University of Queensland, says the temperature on the day surveys were filled out had an impact.

''If it was cold, they were more sceptical,'' said Cook, who is also the founder of the Skeptical Science website. The flip side was also true: ''The more dead plants in the room [where the survey is taken], the more believing they were of climate change,'' Cook said. ''The temperature and the plant [example] just show how malleable people's beliefs are,'' Cook said. ''The most interesting thing is that it happens the most in the middle - the undecided.'' And that middle can be significant. In the US, for instance, about 16 per cent of those surveyed say they are alarmed about global warming, 15 per cent largely dismiss it as a hoax, and the remainder hold varying degrees of concern, said Anthony Leiserowitz, director of the Yale Project on Climate Change.

Both ends of the spectrum have a tendency to jump at weather events to make their case, even though ''no weather proves or disproves climate change because [it] occurs over long periods of time and large areas of space,'' Leiserowitz said. Matthew England, a climate scientist at the University of NSW, agrees: ''The mere fact we have a seasonal cycle on this planet is enough to make our message a very difficult one to explain to the public because people get to winter and they go 'hah, where's global warming now?' '' England himself copped a similar response a week after a paper he was lead author of addressed one of the more complex climate change questions: how come global air temperatures have largely plateaued since 2001 despite increasing levels of carbon dioxide? ''Where's my warming, dude?'' asked News Ltd columnist Andrew Bolt, demanding apologies from England, other scientists and even the ABC. ''In the ocean, dude'', is one answer. England's work, published in Nature Climate Change, argued that stronger trade winds in the Pacific over the past two decades had increased the energy uptake of the oceans by boosting circulation. Waters between about 100 and 300 metres below the surface in the western Pacific had warmed by as much as 3 degrees over the period.

People focus on air temperatures because that's how we experience day-to-day conditions. But it can also mislead because the atmosphere accounts for less than 1 per cent of the heat taken up by the planet, with the oceans absorbing 92-94 per cent and the land the rest, England said. To Cook, the challenge for scientists is to ''fight sticky myths with stickier facts''. The Earth, for instance, is accumulating extra warmth at the rate of the equivalent of at least four Hiroshima bombs per second because of heat-trapping greenhouse gases. Scientists, such as England, are working to explain where that heat is going. As it happens, the CSIRO survey found Australians trusted information from university scientists more than any other group, with oil companies the least trusted. The Bureau of Meteorology and the CSIRO, meanwhile, should soon be able to estimate the role of climate change in significant weather events, such as heatwaves and floods, soon after they happen.

Even that probably won't convince the most diehard of deniers. Opinion drivers Eleanor Glenn’s doctorate at the University of Technology Sydney stems from her scepticism of the assertion that people’s differences over climate change would resolve if everyone was more “climate literate”. Differences of opinion are only superficially about the science, Glenn said. Rather, people tended to take their cue from day-to-day weather and the views of friends.Glenn assembled two groups. One included the leading figures at five leading think tanks, such as Tim Wilson of the Institute of Public Affairs, Sam Roggeveen of the Lowy Institute and John Connor of The Climate Institute.

Despite their public roles, most - but not all - had only a limited grip on climate change science and were “just used to arguing on ideological grounds,” Glenn said. A second group involved 15 members of the West Liverpool Rotary Club. Some of them blamed the sun, or thought a big dam in China had shifted the Earth’s axis, or said it was “in God’s hands”. Finding common ground was most achievable when the focus shifted to showing action could work without sacrificing quality of life.