The actor had been wrapped up in a political storm after appearing in advertising backing the carbon tax. Some had dubbed her ''Carbon Cate''.

Evans followed the debate, and at the end of the 2011 Tour declared to the press: ''Let's just say I like Cate Blanchett a lot.''

Speaking to Fairfax Media this week, Evans said Blanchett's decision to lend her voice to an important, yet unpopular, issue had been courageous ''If they [the government] just didn't use the word tax, it would have gone a whole lot better,'' the champion cyclist said with a laugh.

''I managed to get a personal message to her [Blanchett] to say what you have done there is fantastic. And knowing that sometimes being in the spotlight a little, I know how much courage that takes,'' Evans said.

Evans - who spends off-seasons at Barwon Heads - now wants to make a contribution to environmental issues as well. He has reached out to people such as Australia's chief climate commissioner, Professor Tim Flannery, to learn more.

On Tuesday night Evans will lead an event at Federation Square to promote sustainability in everyday life. It is sponsored by engineering company Siemens, and will be attended by state and federal ministers, along with Professor Flannery.

Evans will lead a peloton of 480 cyclists to power lights in the shape of a Christmas tree with the energy they produce by stationary riding. During the event it is hoped two Guinness world records will be broken: one for most power produced by pedalling on bicycles for one hour, and another for most lights lit by pedal power.

Evans said it was all about spreading a message about a cultural shift to consume less in our daily lives.

''Presented with the statistics, and looking at where we are headed and population and so on, it is pretty obvious we are consuming a little bit too much,'' Evans said.

Evans traces his environmental interests back to his mother, who over the years has given him books on sustainability and climate change. The first he remembers was David Suzuki's Naked Ape to Super Species, which explored humanity's dominance over and damage to the natural world.

But Evans readily admits he is by no means perfect, and concedes there is much more at home he can do to be sustainable. And while cycling is generally seen as an environmental positive, Evans said it becomes less so when you are jetting around the world to compete in races that are televised by helicopters and followed by hundreds of cars and motorbikes.

As Evans has learnt more about the issues, he said he became frustrated and wanted to do something more, albeit between a busy cycling career and a desire to win a second Tour de France.

Where he believes he can be of best use will be lending his profile to help educate about the issues. There are early plans with Siemens to run school programs, for example.

Evans said education and climate change were tied more often than thought, and it would be crucial if there was to be a better understanding of some of the changes to be made.

''It is a slow process, but to make big changes takes time. Ultimately we all will make a cultural change, we are going to have to, if we want to have a quality of life for our children and their children,'' Evans said.