I’M sitting down to write this slightly the worse for wear, I must confess. And yes, I understand that Scotland’s relationship with alcohol is somewhere down there alongside our current international football rankings. But for me it has been a week of emotional extremes.

Yesterday, I was Maid of Honour at the wedding of my dear friend of the past 20-odd years, Rosie Kane, who shot to fame back in 2003 when, after being elected as an MSP, she took the oath of allegiance to the Queen with a raised palm, upon which were scrawled the words “My Oath is to the People”. Since then, we’ve shared the best of times and worst of times. We’ve laughed and sung and danced; we’ve suffered and mourned and wept. And we’ve taken direct action against injustice many times together. Years before I met Rosie, she was an eco-warrior with a difference. A forerunner of Extinction Rebellion with a working-class Glaswegian accent.

Back then, people who protested against motorways, genetically modified crops and the destruction of nature were widely viewed as privileged eccentrics. Rosie may have been – and still is – an unconventional free spirit but she was anything but privileged. She grew up in a rough, tough housing scheme on the south side of Glasgow (and has since returned to live a few doors down from her childhood home) and was a single parent bringing two daughters up on the breadline when she joined the Pollok Free State anti-motorway protest, a jumble of tents and trees, open fires and wigwams on the proposed route of the M77.

Warm, friendly and funny, she was also way ahead of her time – and I was privileged to deliver a speech in her honour on Saturday, before succumbing to the wine. Rosie herself paid tribute to another outstanding woman who was tragically absent and sadly missed. I’ve written in this column about Roz Paterson’s courageous and inspirational fightback against a deadly cancer, as she battled to stay alive in the hope she could see her two young children grow up. A week ago today, she finally lost that battle. On Saturday night, in Pollokshaws, we had a minute’s emotional applause in tribute to the memory of Roz.

On the face of it, Rosie and Roz were different. Rosie, gregarious and a natural orator; Roz, unassuming and wary of the limelight. But both warm, generous and caring. And both with a deep commitment to environmental as well as social justice. “The signs are everywhere,” wrote Roz many years ago. “In the creeping rise of the oceans and the low lands that slip beneath them. In the monstrous hurricanes that lay waste to everything they touch. In the chunks of ice that break free from the evaporating ice fields. In the heatwaves and howling storms, the flooding and famine. And we are the architects of this destruction. Through massive over-consumption, reckless industrialisation and chronic inability to top face the truth, we have brought our planet to this impasse. Now we must act to save it.”

Eloquent and true. And now even the mainstream politicians are beginning to shuffle uncomfortably and acknowledge, finally, that yes there might be a problem.

Climate change has been described as the greatest crisis that the human race has ever had to confront. But it’s not just about reducing or even eliminating our use of fossil fuels to reduce carbon emissions. It’s also about how we use and abuse our land and seas. Roz Paterson wrote prolifically about the wholesale depletion of the natural resources of our planet – the forests, the rivers, the plants, the insects, the birds the animals – to feed a frenzy of profit-driven consumption. And last week we learned that a million species are at risk of extinction as humans continue to wage war against nature on a global scale.

When the SNP unveiled their Sustainable Growth Commission report, they attracted diverse responses. Some on the left denounced it as neo-liberal. Others as too timid. Labour claimed it was a charter for a decade of austerity. The right denounced it for failing to face up to the need to confront austerity. And the SNP leadership naturally defended the report they had commissioned.

But a few fundamental points were left unaddressed by both supporters and opponents. Do we actually need ad infinitum economic growth? And if we do, what do we grow – and what do we shrink? And what exactly do we mean by sustainable? For economists, society’s health is always measured by the crude statistic of GDP. If it’s rising, then you’ve a successful economy. If it’s falling, your failing. But what if we stopped arms production? Closed down Trident? Slashed defence expenditure to the level of the Republic of Ireland? Rooted out waste, duplication and corruption? Slashed crime rates to negligible levels? Massively cut the number of deaths and injuries on our roads? Cut down on junk food? Drastically reduced our alcohol consumption and completely marginalised smoking.

Measured by GDP, all these changes would make us poorer. But in the real world, not of economic graphs and pie charts, but of real human beings and the natural environment, we’d be richer by far. And happier, And healthier. And more optimistic. At Rosie’s wedding, I had a brief conversation with Katherine Trebeck, research director at the Wellbeing Economy Alliance whose work deserves to be studied deeply by every politician and political party serious about building a fairer, more socially just, more environmentally responsible society. But first they’ll have to discard much of the pickled dogma of mainstream economics and open their minds to a different way of looking at the world.

On Saturday, I heard Georgia McGarvey, a niece of Rosie’s from Donegal, sing a hauntingly beautiful rendition of Louis Armstrong’s Wonderful World. We do live in a wonderful world, where life is both precious and fragile as has been brought home forcibly to me in this week of light and shadow.

But the damage from human consumption needs cleaned up. Our planet needs revitalised. It needs transformed. So, when we think of a future independent Scotland, let it be the as part of a wonderful world we take responsibility for – and lead the way to that transformation.