When MPs announced a citizens’ assembly on the climate emergency last June, two crucial things hadn’t yet happened: Boris Johnson’s takeover of the Conservative party; and the subsequent general election campaign where the main opposition parties each offered radical plans to address the climate crisis, and then lost to Johnson, who had offered no plan at all.

For everyone hoping for action on climate, the election was a particularly bruising experience. First throwing open the door to a previously unthinkable possibility – immediate, concrete plans to fight the crisis, far beyond anything proposed by the inadequate Paris Agreement – and then, just as quickly, slamming that door shut. Perhaps even more tightly than before, given Johnson’s disinterest in all things climate-related. And because now the party without an apparent serious climate plan is in charge of taking the critical first steps towards Theresa May’s government’s goal of hitting net-zero by 2050, while the parties willing to commit to action are shut out of power by the enormous Tory majority.

The climate assembly – which met for the second time in Birmingham last weekend – was created to act as a kind of workaround for traditional partisan deadlock, and to chart a safe route forward for governments to act on the climate crisis. Its conceit is that it offers direct access to the real will of the people: 110 citizens – chosen to be representative of the British population – attend sessions where they are briefed by experts on the issue; they then come up with a set of policies to solve it. A citizens’ assembly in Ireland helped the government to put forward the referendum that ended that country’s abortion ban last year.

The best chance for tackling the climate crisis comes from politicians and parties who don’t wait for incremental solutions

The mood at the assembly so far has been hopeful. The setup assumes that our political leaders have the best intentions, but are paralysed by indecision, both because of the unfathomable number of options and the fear that the public will punish them for the wrong choice. The whole function of politics here is outsourced to the public: they’re asked to make their own tough decisions. And so they have sat attentively listening to presentations on the greatest hits of never-tried climate policy, and have been asked to weigh them up. There was mention of personal carbon allowances (be your own carbon market), a very popular idea in 2008, and more recent schemes such as creating nationwide repair networks, and forcing manufacturers to build goods to last.

All the solutions presented reflect the mainstream of British climate policy over the past two decades. The experts put forward a fairly cautious mix of technocratic market incentives and regulation, with large spending programmes reserved for infrastructure projects. Still, there were signs that the assembly might take some bold decisions. The experts barely mentioned free public transport, yet were quizzed on it incessantly. And the members wanted to know who was most responsible for emissions, and how they could be made to pay. The polls suggest that public opinion has leapt ahead of the government’s climate ambition over the past year, and it’s possible that the assembly recommendations will confirm that.

But even if the assembly puts the most progressive options in front of the government, there’s still the sticky question of implementation. “How can we be sure the government will follow on our recommendations,” an assembly member asked Labour MP Rachel Reeves, one of only three elected officials in attendance. She didn’t have a good answer, but she could easily have told them it’s not on her – she’s only ever been in opposition during her 10-year tenure in parliament. The assembly’s most valuable contribution may be breaking the deadlock between equally effective but controversial policies – a land-use carbon tax or a consumption tax, for example – although the Tories may well choose neither. The problem with how to tackle the climate crisis in the UK is not partisan deadlock, but lack of government interest.

‘The mood at the assembly so far has been hopeful. Its members assume that our political leaders have the best intentions, but are paralysed by indecision.’ Members of the citizens’ climate assembly listen to a presentation. Photograph: Fabio De Paola/PA

A citizens’ assembly can’t change that. Its decisions aren’t guaranteed to sway the government from its prearranged course. The Irish assembly is held up as a model for its recommendations on the abortion referendum. However, it also submitted proposals on the climate crisis, from huge investments in peat restoration and public transport to a tax on agriculture emissions. The Irish government ignored all of these, in favour of what the prime minister, Leo Varadkar, called “ambitious but realistic” policies to “nudge people to change behaviour”. Nudging people towards radical change is a depressing continuation of the managerial away-day optimism that has dominated thinking on the climate crisis over the past 20 years. One would have better luck trying to nudge a stream back up a mountain.

Instead, the best chance for tackling the crisis comes from politicians and parties who don’t wait for incremental solutions. Party politics has become an unexpected laboratory for fusing climate policies to big, popular, social spending programmes – based on the model of a green new deal, which was first put forward by experts in 2008. Unlike a sitting government, opposition policy shops are a frictionless environment: ambition can be doubled and redoubled without pushback.

And if the programmes capture the public attention, they are quickly copied by other parties. Labour proposed a green industrial revolution based on using the resources of the state to foster green industries, creating jobs and increasing living standards. This in turn pushed the Liberal Democrats to try to match the offer – remarkable for a party committed to the decentralisation of state power. In the US, the Bernie Sanders campaign is not only currently leading the polls to win the Democratic nomination with the Green New Deal as a top-line policy, it has also pushed every other candidate towards embracing the idea – something that would have seemed impossible just four years ago.

For a long time it has been assumed that public opinion is a barrier to climate action. But the climate assembly will likely confirm what the polls have been indicating for the past year: that people are now ready to move further and faster on climate action than the minimal effort shown by the government. If their advice is ignored or diluted beyond recognition, then maybe citizens’ assemblies are an imperfect mechanism for the scale of change needed to tackle the climate crisis. Only a green new deal for the UK will do.

• Stephen Buranyi is a writer specialising in science and the environment