Thousands of people gathered in the Australian capital, Canberra, to protest against a planned carbon tax aimed at curbing greenhouse emissions.
It is the centrepiece of Prime Minister Julia Gillard's environmental strategy, despite her ruling out its introduction during last year's election campaign.
A year on from that pledge, conservative opponents, who opposed the measure, are calling for new elections.
They say the tax will drive up household bills and cost jobs.
No issue in Australian politics is generating more passion right now than climate change, says the BBC's Nick Bryant in Sydney.
This was an orderly protest, but an angry one, with the anger directed at Julia Gillard - "Ju-liar" in the wording of a couple of placards brought to the rally, our correspondent says.
Protesters say this is not only the first day of parliament's spring session but also the anniversary of a pledge that Ms Gillard made during last year's federal election not to introduce a carbon tax.
The proposed tax would penalise 500 of the country's heavy polluters.
I'm not here to discuss whether or not a carbon tax is good or bad. My person opinion is that Australia should have one. My personal opinion about the tax itself is that it is fairly hamstrung by concessions to Big Business. After that, I try to cut out the toxic debate that is going around, or, at least, I have tried.
But I think this debate, and I use the term loosely, is having a very negative impact on how science is being viewed in our society. Under attack but voiceless, science and scientists are not being presented as people who spend hours and days and years researching and studying and trying to help the world. This is not an attack that is limited to the conservative side of politics, either, I might add. The other month, Greenpeace broke into the CSIRO and destroyed a GM wheat crop--an act that, lets be frank, is entirely unacceptable. It brings to mind people burning those who said the world was not flat, or killing doctors who perform abortions, a frame of mind that we have, as a society, should be ashamed of. Actions such as this show no intellectual debate whatsoever. You don't like it, you grow your own GM crop and you get the results and you publish them against it.
But the attacks against science are not limited there. Take the Australian, for example:
Jane Fraser, columnist in The Australian , writes a column based on "facts" she got from a chain email:
Back to Plimer. He says he knows how disheartening it is to realise all your savings on carbon emissions have been eaten up by natural disasters. You've suffered the inconvenience and expense of driving Prius hybrids, buying fabric grocery bags, sitting up 'til midnight to finish your kids' "The Green Revolution" science project, using only two squares of toilet paper, putting a brick in your toilet, selling your speedboat, holidaying at home instead of abroad, replacing all those light globes that cost you 50c with ones that set you back $10 . . .
Well, he says, it took just four days to flush all these good works down the drain. In those four days the recent volcanic eruption in Iceland spewed enough volcanic ash to negate every single effort you have made in the past five years to control CO2 emissions.
This is not true. Fred Jourdan (Prof. of Applied Geology, Curtin University of Technology) states:
The eruption in Iceland emitted a fairly small amount of CO2. In fact most recent estimates show that the flights that were grounded by the eruption would have emitted about twice as much CO2 as the volcano itself.
Fraser continues with:
Plimer adds he doesn't want to rain on our parade too much (not half!), but he should mention that when Mt Pinatubo erupted in The Philippines in 1991, it threw out more greenhouse gases into the atmosphere than the entire human race had emitted in its entire time on earth.
This is wrong by a factor of 30,000. Each year humans emit 700 times as much as Pinatubo did.
I agree with most of what Plimer says. It makes sense to me.
Not only is it the case that the stuff about volcanoes that Fraser repeats is untrue, Plimer didn't say it. While Plimer has said things about volcanic emissions that are stupidly wrong, he didn't write the email that Fraser is quoting. As often happens with chain emails, Plimer's name got added to the original version of the email at some stage.
The blog I am linking to is up to 68 versions of the Australian misrepresenting science and I am starting to think, with all this stuff going around, that there's a depressing vibe going on in this country.