Here's the science, what's the hold-up?

When David Karoly was asked at Tuesday's keynote address, on day two of Carbon Expo in Melbourne, how media and scientists should go about the task of conveying the serious nature of human induced climate change without engaging in scare mongering, his answer was: not this. "The worst thing you can do is what I've done here today," said the Professor of Meteorology and ARC Federation Fellow in the School of Earth Sciences at The University of Melbourne, "and only deliver the bad news, without the good news."

Karoly – an old stager around the climate science circuit who has been, at various times, a government adviser on climate change and a lead author on the IPCC – says this with meaning. From the slightly frayed humour and the sad-but-true cartoons in the slide presentation, you get the feeling he has delivered different incarnations of this half-hour speech, "updating the science," time and time again to audiences around the world (indeed, a NZ-targeted slide found its way into this presentation); to what might, at times, seem to little avail.

But he keeps saying it, and saying it, in the hope that it will begin to sink in. And here's what he's saying: the earth is warming and human emissions of greenhouse gases are the main cause of this; the rates of change to the earth's climate systems due to global warming are happening at or above scientific predictions; and yet, public acceptance of, and confidence in, the science has weakened.

Why is this so? Media-driven misinformation? Politics? Too scary a message? All of the above, probably. Karoly says he has, on several occasions, been called "the scariest person in Australia." And, he concedes, "the message is very scary." He says some of the most alarming news has come this week, with the global output of heat-trapping carbon dioxide jumping by a record amount, according to the US department of energy. The globally accepted emissions reduction target of 5 per cent by 2020, even if implemented all around the world, will now not be enough to slow global warming, Karoly says. This is the critical decade to get serious.

As for the good news (that the technology already exists with which we can begin drastically cutting our CO2 emissions, and that it could be great for our economy and for jobs and for the environment), the delivery of which Karoly says is vital to the message of climate change, he hands that job to the speaker following him, Parliamentary Secretary for Climate Change, Mark Dreyfus. And on a day when the government's Clean Energy Future package is expected to pass through the Senate and into law by early afternoon – a step Karoly describes as "very, very important;" a small step for Australia, he says, but like the first lunar landing, possibly "a giant leap for mankind") – he seems confident this can be done. "This legislation can make a difference," Karoly told conference-goers. So over to you, Mark Dreyfus, et al.