On a steamy afternoon in Sydney last Sunday, about 45,000 people turned up to walk the short distance from the Domain to the Opera House. I was one of them. We – together with hundreds of thousands of others across the globe – hoped to make some impression on the policy-makers gathering in Paris to discuss, yet again, the vexed issue of climate change.

I am not a frequent participant in protest marches. In my opinion, they don't have a great record of success. Over the weekend of February 15-16, 2003, some 10 million people worldwide marched to protest against the coming war in Iraq – including about 200,000 in Sydney, 150,000 in Melbourne, and as many as a million in London. The US president George W. Bush launched the war anyway, with the enthusiastic endorsement of the Australian and British governments.

Compared to that global demonstration, Sunday's efforts in Sydney and Friday's in Melbourne were modest – considering what's at stake, disappointingly so.

Still, many thousands of marchers were worth a couple of minutes on the TV news, you would think, and a few pars with a picture on an inside page of the newspapers the next morning. The Herald Sun in Melbourne ran a story in Saturday's paper but the Sydney rally was ignored by both Channel Nine news and the Daily Telegraph.