More than the wreck of the Braer oil tanker off the Shetlands. And more than Friends of the Earth, Greenpeace, the World Wide Fund for Nature et al who have repeatedly found themselves sidelined by the likes of the Dongas tribe in the battle for Twyford Down and the angry citizens of Wanstead, north-east London.
For while the mainstream green pressure groups have continued earnestly to lobby the Government and produce fat reports and press releases, it was occupying trees, invading construction sites and getting sent to jail by magistrates and High Court judges that seized the public imagination.
These protesters may wear daft hats, like the man on the right protesting outside the Department of Transport yesterday. Some do not have proper jobs or homes. Some may bathe irregularly. But they have kept traffic, pollution and the issue of reconciling economic growth with planetary survival in the news.
'They've been brilliant at keeping green issues on the agenda at a time when the pressure groups have struggled,' said Sara Parkin, a former Green Party leader. 'They're not just hippies or New Agers, they're grannies and ordinary people making a personal commitment. It's tremendous.'
Yesterday, about 100 damp but defiant protesters marched through wind and rain to the enemy's citadel, the Department of Transport's grey and towering headquarters in Marsham Street, Westminster.
They carried a sweet chestnut sapling. They wanted the department to plant it as a replacement for the 250-year-old specimen smashed down in Wanstead, east London, three weeks ago to make way for the M11 link road.
No minister descended to meet them. A civil servant, Ian Minards from the information department, emerged to receive the tree. 'It's not my job to say anything,' he told them when they demanded a speech.
They also gave him a selection of the many letters sent to the chestnut during the weeks when protesters lived on a platform in its branches, defying a court possession order.
Roger Geffen, one of the organisers of yesterday's march, said their strategy was now to occupy, rebuild and barricade dozens of the 350 condemned homes that lie in the path of the three-and-a-half mile, pounds 230m road.