If things had been different, Rishi Sunak might have topped off his trip this week to the G20 summit in Bali with a quick dash back to Sharm el-Sheikh for the final hours of Cop27. But gone, sadly, are the days when getting a climate deal over the line was top priority for world leaders. Now they prefer to show up for the opening ceremony and then leave. It’s safer to grace the platform when there’s only hot air and the moral high ground at stake. And besides, Sunak has a diary clash tomorrow. He and Jeremy Hunt don’t have time to save the planet. They have to try to save the Tory party. Like a couple of cleaners wading around in the aftermath of a bloodbath, the prime minister and his chancellor have been warning everyone for weeks how messy things are going to be in their autumn statement. Cut spending. Raise taxes. Raid pensions. Everyone is going to have to make sacrifices. Nothing is off the table. Nothing, that is, except identifying (and punishing) the architects of the chaos. Admittedly, this particular crime scene was carnage, so apprehending the villains was never going to be easy – particularly after the most obvious culprit fired her co-conspirator and then fell on her sword. Even the cleaners could see that the Liz Truss and Kwasi Kwarteng mini-budget was the most immediate cause of the “eye-watering choices” now facing them. Lurking in the background were the unprecedented global conditions prompted by the war in Ukraine. Not to mention the failure to insulate our homes against rising energy costs. “These are tough times for people everywhere,” wrote Hunt in his latest constituency column. It’s a sentiment that doesn’t quite gel with the dramatic increase in profits from the energy companies and the banks. But behind all this is the rumble of something more pernicious and more deeply rooted. The spark that lit the Trussonomics fire was the siren call of “growth, growth and growth”. The utter fantasy of trickle-down economics was given a brand new lease of life by Kwarteng, several decades after it patently stopped working. In her ill-fated conference speech, Truss pulled no punches. It was the anti-growth coalition who were holding Britain back. Her government would root them out once and for all. This is where the forensic trail gets confusing. Strangely, most people on her target list were as gung-ho for growth as she was. Barely two months before that speech, Keir Starmer had offered – almost word for word – the same prescription. After painting a not-inaccurate picture of a broken social contract, the leader of the opposition explained how three things would be needed to fix it. “Growth. Growth. And growth.” The maths is off, but the call is familiar. Though they trumpet “stability first”, Sunak and Hunt are as obsessed with economic growth as the rest. It’s only their specific prescriptions that differ. They lean ideologically towards austerity 2.0. But in one sense, there’s not much difference between tax giveaways and huge public spending cuts. Both of them hurt the poor more than the rich. All of it is legitimised by the promise of growth. None of it actually works. Growth in advanced economies has been declining for decades – not just since the financial crisis but since the mid-1960s. The former US treasury secretary Larry Summers has argued that the growth rates yearned for by politicians may now be a thing of the past. Most reactions to this unwelcome news consist of denial and a frantic attempt to kickstart growth again. Cheap money, tax cuts, fiscal stimulus. Or high interest rates, deregulation and fiscal austerity. Round and round we go. More of the same will emerge tomorrow. Like an economic whack-a-mole, we smash away at the underlying problem in one place only to find it surface somewhere else. Could it be that our growth fetish was the villain all along? Our attempts to prop up an ailing capitalism have only hindered the investments needed to reach net zero, reinforced inequality and undermined stability. Seen kindly, the Tory mess is then a symptom of this deeper dynamic. More likely, it’s a concerted effort to protect the first-class passengers on a sinking liner. What’s clear is that, to all intents and purposes, we’re already living in a post-growth world. And it’s time to take that challenge seriously. To focus on protecting wellbeing. To distribute wealth fairly. To invest in the care economy. To improve education. To strengthen community. To build an economy that works for everyone. And to turn up at Sharm el-Sheikh with something more than empty promises. Saving the Tory party is a lost cause. Saving our kids from runaway climate breakdown may still be a possibility. But only if we face this new reality. Tim Jackson is professor of sustainable development at the University of Surrey and director of the Centre for the Understanding of Sustainable Prosperity