Public opinion was behind the government when it signed the Kyoto Protocol in 1998 and then formally ratified it after a parliamentary debate in 2002, says Goldenberg.
But he doubts Canadians were "then immediately ready for some of the concrete implementation measures that governments would have to take to address the issue of climate change.
"Nor was the government itself even ready at the time with what had to be done," he said in a speech prepared for delivery to the Canadian Club of London, Ont.
"The Kyoto targets were extremely ambitious and it was very possible that short-term deadlines would at the end of the day have to be extended."
The protocol, a United Nations-led agreement, calls for Canada to reduce greenhouse gas emissions by 6 per cent below their 1990 levels by 2012.
In 2005, the Liberals under then-prime minister Paul Martin tabled a $10 billion plan to cut emissions between 2008 and 2012. But last fall, former Conservative environment minister Rona Ambrose said there was no possibility of Canada meeting its Kyoto targets and blamed the Liberals for failing to put Canada on track to do so.
In his speech, Goldenberg says even if the Chrétien government was ill prepared to follow through on its Kyoto commitment, signing the accord was vital to alert Canadians to the task of addressing climate change.
"We knew that signing and ratifying Kyoto when we did was absolutely necessary to prepare public opinion for the actions that would have to come in the future," he says.
"The signing of the Kyoto Accord in the face of vigorous opposition served to galvanize public opinion to bring it to where it is today in Canada. In the long run that will be far more important than whether we can meet all the short-term deadlines in the accord."
John Baird, the Conservative environment minister, said he wasn't surprised by Goldenberg's comment. "We always knew that the Liberals had no plan, they took no action and had little intention of doing so," he told reporters in Ottawa.