A historic moment for anyone who cares about the environment

History doesn't always come in thunderclaps or cheering crowds, and yesterday it was made with very little outward fuss when a woman in a pale blue trouser suit got to her feet from a green leather bench and began to speak.

It was precisely 3.30 in the afternoon, and the Deputy Speaker of the House of Commons, Hugh Bayley, had just issued a two-word invitation: "Caroline Lucas." And with that, the first MP of the Green Party, in fact the first MP of a new national party for many years, began her maiden speech and her party's political life at Westminster. Henceforth, the environment has its own representation in our politics.

It had been a long journey to get there, she said. Indeed it had: nearly 40 years from the Green Party's origins as the Ecology Party in the 1970s, and nearly 20 years in the case of Ms Lucas herself, who began her rise in the party at the moment of the Greens' false dawn: in the Euro elections of June 1989, when they got 15 per cent of the UK vote, burst on to the national political scene, and then blew it.

Thrust into the spotlight, such were the antics of the Greens' grassroots, rejecting the "cult of leadership" and insisting that the party spoke with several voices at once – I listened to the debates with an inward groan at Green Party conferences at places like Wolverhampton and Bridlington – that by the mid-1990s they had dissipated their credibility entirely and had become little better than a political joke. Caroline Lucas has led the way back to reality, and to the realisation of the truly noble aim of having a politics based on concern for the Earth, as much as on concern for equality, or freedom – the ideal of Petra Kelly of Germany's Die Grünen, the charismatic inspiration for Green parties the world over.

I have followed her long journey closely over those two subsequent decades, and many key moments are etched on my mind. There was a midnight meeting in Oxford in 1992 with a troubled Petra Kelly herself, shortly before she was murdered by her partner; a 4am moment of euphoria in Winchester Town Hall in 1999 when Ms Lucas was elected as the Greens' first Euro MP; the moment in 2007 when she was adopted as candidate for Brighton Pavilion, the one parliamentary constituency where the Greens had a realistic chance of success; her winning of the fight for the party to have a single leader, in 2008, and then the securing of the post for herself; and finally the election night marvel at 5.45am in Brighton's conference centre on 7 May, when she and her supporters realised that they had broken through the wall into Westminster.

That was an unforgettable occasion of cheers and wild delight – in a weird way, it was like witnessing a baby being born – but somehow even that was eclipsed for me by yesterday's event, calm, composed and routine.

It was so routine, in fact, that I was the only observer in the Press Gallery, apart from two guys from Hansard, the official recorder of parliamentary debates, and a chap from the Press Association, the national news agency. There were 31 people in the public seats, and fewer than 50 MPs in the chamber. There was no roll of drums. There was no fanfare. But when this 49-year-old former Oxfam adviser got to her feet, I could not suppress my own sense of history being made; for here it was. It was real, after all, it was really happening: the voice of the environment was at last being heard in the Mother of Parliaments, long after it had resounded through every other national legislature in Europe.

You had to go back several decades, she said, to the election of the first Nationalist MPs in Scotland and Wales, to find the last maiden speech from a new national political party.

She went on: "And perhaps a better comparison would be those first Socialist and Independent Labour MPs, over a century ago, whose arrival was seen as a sign of coming revolution. When Keir Hardie made his maiden speech to this House, after winning the seat of West Ham South in 1892, there was an outcry, because instead of frock coat and top hat, he wore a tweed suit and a deerstalker... but what Keir Hardie stood for now seems much more mainstream: progressive taxation, votes for women, free schooling, pensions, and abolition of the House of Lords.

"And though the last of these is an urgent task still before us, the rest are now seen as essential to our society. What was once radical, even revolutionary, becomes understood, accepted and even cherished."

MPs in their maiden speeches traditionally sing the praises of their constituencies, and Ms Lucas followed Tom Greatrex, singing the praises of Rutherglen and Hamilton West, and Angie Bray, lauding the virtues of Ealing Central and Acton, in making sure the Commons knew the virtues of Brighton. In fact, the bohemian bit of the Sussex seaside resort, centred on the Pavilion constituency, is the Greens' spiritual home, and Ms Lucas hinted at this, remarking: "You have to work quite hard to be a 'local character' in Brighton" before going on to praise the Lanes, the Conference Centre, the Pier, the Royal Pavilion, the entrepreneurial spirit of the people, the beauty of the Sussex countryside, and the achievements of her predecessor, the Labour MP David Lepper.

But the markers she put down about her future activities constituted the meat of her speech. Climate change would be a major concern, she said, and she went on: "Politics needs to renew itself, and allow new ideas and visions to emerge. So I hope that if, and when other new political movements arise, they will not be excluded by the system of voting. Reform here, as in other areas, is long overdue." Electoral reform, she said, "means more than a referendum on the Alternative Vote: it means the choice of a genuinely proportional electoral system."

Furthermore, she told the House, one of the things a single MP could do was raise issues which could not be raised elsewhere, and despite the tradition of maiden speeches being non-controversial, she broached the issue of the commodities trading group Trafigura and the shipping of hazardous waste to Ivory Coast – an issue which was not being reported in Britain, she said. She added: "These are the kind of issues I would like to pursue."

The House of Commons has been warned.

Extracts from the maiden speech

Our message

"If our message had been heeded nearly 40 years ago, I like to think we would be much closer to the genuinely sustainable economy that we so urgently need, than we currently are today."

Climate change

"I have worked on the causes and consequences of climate change for most of my working life, first with Oxfam – for the effects of climate change are already affecting millions of people in poorer countries around the world – and then for 10 years in the European Parliament. But if we are to overcome this threat, then it is we in this chamber who must take the lead."

Single MPs

"Both before the election and afterwards, I have been asked the question: what can a single MP hope to achieve? I may not be alone in facing that question. And since arriving in this place, and thinking about the contribution other members have made over the years, I am sure that the answer is clear, that a single MP can achieve a great deal."