A child of 1970s Italy, Polini, 36, has volunteered for NGOs and attended demonstrations since her youth. 'After fascism died there was lots of political activity. You had to take a side,' she points out.
Growing up with an ex-soldier grandfather and a trade unionist father, there were always 'passionate debates and discussions' at home. But Polini has never been one to throw stones. She is a pacifist, and 'peaceful protest' is what attracted her to Greenpeace, both as a youngster and when - just over a month ago - she took its top global PR role.
As far as possible, Polini lives by Greenpeace's principles. She cycles or takes public transport and has a solar panel on the roof of her Chiswick home. She flies as little as possible - although, with her global remit, she cannot avoid planes entirely.
Despite living in London for ten years, Polini does not hesitate to name her birthplace, Rome, as home. She lives between Amsterdam, the location of Greenpeace's global HQ, and London - Greenpeace 'lives and breathes media', she says, and Polini watches more news now than she ever did in her former life as a reporter.
She describes her work as 'journalism with an agenda. It's push and pull - all day we're putting our messages out, while reacting to outside events'.
There are, of course, frustrations. As a not-for-profit organisation that does not accept government or corporate donations, Greenpeace often lacks the resources to match its ambitions. On a global scale, there are dangers that come with activity in southern hemisphere countries, where NGOs are a new concept. There is also the challenge of the politically hostile US, particularly around climate change.
And Greenpeace has an image problem - the militant, radical stereotype to dispel. For Polini, this perception could not be further from the truth. But the organisation is looking at new, less confrontational methods of 'mobilising the masses', such as a recent 'virtual demonstration' in South Korea, in which protesters took part using their computers.
However, working at Greenpeace is hugely satisfying for Polini: 'I've never seen anything like it. Everyone works so hard. Being driven by what you believe in makes a world of difference. People don't mind working night and day to push harder for change.'
Her interests include Yoga, meditation and 'crystal healing', and she lives in a 'calming house, full of buddhas and candles'. But she dislikes being pegged as a hippy. Sartorial elegance aside,
she previously worked at Mars for seven years.
Polini married a Mars colleague three months ago and is passionate about the confectioner's ethics. While there, she helped pioneer a corporate social responsibility scheme. Cause & Effect CEO Manny Amadi, whose consultancy worked on the project, describes Polini as 'a hungry spirit' with 'the desire to make things happen'.
Starting her career as a journalist, all her jobs have involved a deep love for communication. She speaks seven languages and has four degrees, the most recent of which - a Masters in Responsibilities in Business Practice - she studied for part-time while at Mars.
After Mars, Polini felt the next step was to work for an NGO: 'It may sound messy, but in my head it's quite a clear path, bringing together my communication skills and my beliefs.' Again, Polini sought to see the world from a different perspective.
Fittingly she loves the ocean and spends her holidays scuba-diving. 'I think I was a fish in a previous life,' she laughs. If Greenpeace does want to tone down its radical image, Polini is its perfect poster child.