Instead of growing all the time, the other way is to grow up and realise that we live in a finite world. Ultimately it goes to big philosophical questions about the kind of people we are and what it means to be human
Brexit has shifted UK climate policy in an "immensely scary" direction and put a question mark over the survival of Britain's pioneering climate change act, according to Professor Tim Jackson, a sustainable development expert and adviser to British governments and political parties.
The 2008 act was among the first global laws to rein back runaway emissions and helped cement the UK's claim to climate leadership. Since last year's Brexit vote though, Theresa May's administration has pushed to water down core EU energy saving laws and told civil servants to scale down climate action, as leaked documents show.
Jackson said that provisions in May's planned 'great repeal bill' allowing EU law to be changed without parliamentary consultation, left the UK in "an immensely scary place to be".
"The key question is whether the UK Climate Change Act can survive," he said. "The act was groundbreaking and all administrations up to now have stood behind it, but when the going gets tough will they continue to do so? We just don't know."
Over the next two or three decades, structural pressures would force any UK government to get serious about energy waste he said, on the fringes of a week-long convention, organised by the European council for an energy efficient economy.
"A country with a net energy deficit has to think about its international trade position. As we get more isolated because of Brexit, that means being more efficient with resources because energy efficiency is one of the things that can make a difference."
Jackson is an academic, author, and former economics commissioner of the UK's sustainable development commission. A current advisor to both the Labour party and Whitehall departments, he says: "my sense is to work with the Government in power to create conditions for change, even with governments that you don't really favour."
His current involvement in government networks spanning the Cabinet Office and Number 10 policy unit followed a promise that the Tories were moving in a more progressive direction. But "it's sometimes difficult to hold that faith in the context of what's happening with Brexit," he admits.
The UK is not alone in currently bucking the climate logic of energy efficiency laws. Many EU states - particularly in east Europe - are vehemently resisting legislation needed to fulfill pledges made by the EU at the Paris agreement, which they themselves signed up to.
Part of the problem is that energy saving is "not a big sexy technology kit that implements itself with multi-milion dolar contracts," said Jackson, a Surrey University professor. "It's more a series of almost housekeeping issues."
These have to be rolled out across the housing, infrastructure, and transport sectors where they offer returns that are solid and dependable, albeit lacking the fireworks needed to woo policy-makers committed to a 'growth'-filled political horizon.
"The biggest casualty of that strategy is that is you just push the industries that can increase their bottom lines, whatever they're doing to the environment, and it is a recipe for disaster," Jackson adds. "You create more and more insufficiency in society - only more efficiently - so that you are effectively doing the wrong thing faster and faster."
Robust prosperity, he argues, is about the wellbeing of citizens, families, children and society. 'Growth' is a means to that end, that is largely unexamined, he argued in his acclaimed 2009 book, Prosperity without Growth.
"A ‘post-growth' economy is a precise, definable and meaningful task, but there's no immediate reward for any politician who advocates it," Jackson says.
Young people and trades unions form key constituencies for change, because of the huge insecurities and disenchantment wrought by the 2008 financial crisis - "a system on the brink of chaos and social turbulence," he notes wryly, "which is a long way from putting loft insulation in a roof."
But in a consumer society geared towards instant gratification, how can constraints and limitations - the things you can't do - be anything other than a 'hard sell'?
"There are two ways to change it around," Jackson replies. "One is to run headlong into those limits - and then see how much you like them. That's route number one, which is a little bit where we're going at the moment."
"Instead of growing all the time, the other way is to grow up and realise that we live in a finite world. Ultimately it goes to big philosophical questions about the kind of people we are and what it means to be human. You don't have to go all the way, but a little bit of that can prevent you from racing head first into a car crash."
Arthur Neslen is an environmental journalist for the Guardian and other climate-related media. He has previously written two books, and worked for the BBC, the Economist, Aljazeera, and Euractiv