Democracy was "never secure nor finished", and was about more than simply voting every three years.
Access to information was critical to a functioning democracy, he said, yet the Official Information Act (OIA) had become "relatively moribund".
"I think we've got a problem with accessing information in this country," he said, referring to a recent court order against the Government over the way it decided against releasing information about the Trans-Pacific Partnership.
It was "hard to get straight answers" at Question Time since the departure of former Speaker Lockwood Smith, under whom the regular question and answer session was "electric".
"Let me try to be diplomatic... It is no longer answer time and I believe that is a big problem for our democracy."
Dr Norman bemoaned the under resourcing of media organisations in New Zealand and the "bad culture around dissent" which had seen Eleanor Catton and Nicky Hager publicly vilified for speaking out about the Government.
The departing Green MP, who is leaving to head the New Zealand branch of Greenpeace, said the worsening pollution in New Zealand's rivers should be a "wake up call".
New Zealand needed to confront the fact that it had too many cows on its dairy farms and there was no infinite capacity to absorb the country's pollution.
On poverty, he said Governments could not do everything.
"They say Governments can't mend a broken heart. But Governments can fill an empty stomach."
Dr Norman became emotional when speaking about his wife Katya Paquin, who had been a "tremendous" personal and political supporter.
"You've changed me in ways I never expected, as having kids does to you."
Ms Paquin held a senior role with the Greens before she left "for a much more important job", raising their three children.
After a string of tributes to former leaders Rod Donald and Jeanette Fitzsimmons and others, Dr Norman finished on an optimistic note.
"Humanity faces some really great challenges in the years ahead. But we also have huge opportunities. Human creativity is infinite. .. Human courage is infinite.
"And we have the opportunity to create a world of abundance for everyone living within the finite limits of the world."
He urged New Zealanders to "stand up for a better world, regardless of the cost".
"We are all entitled to be agitators and we should exercise that entitlement frequently," he said, before signing off: "I intend to do so."
