Last week began with Brexit chaos and ended with climate action. We are living through a time of climate emergency and democratic crisis – and I believe we are more likely to respond to the emergency if we also address the crisis.

In little more than a generation, we have gone from the fall of the Berlin Wall and Francis Fukuyama’s famous assertion that history had ended with the triumph of liberal democracy, to the rise around the world of polarisation, populism and pessimism.

Inequality levels are spiralling, social mobility has stalled, public services are crumbling. All around us are signs of social stress, from violent crime to near epidemic rates of mental illness. Whatever happens now with Brexit, there is little evidence that the underlying anger and resentment that fuelled it has subsided.

Things are bad, but with the effects of Brexit still to play out, with the underlying causes still untouched, and with right-wing populists ever ready to exploit the situation, they could get even worse.

Our ancient political system is proving incapable of addressing 21st century crises. Representative democracy provides an incredibly blunt mandate – especially under the first-past-the-post system. Every five years a government is elected, generally with the votes of less than a third of the population, on the basis of a take-it-or-leave-it manifesto containing hundreds of policies. In power, that government will potentially have to respond to a whole new set of issues. There has to be something better.

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That doesn’t mean we should abandon democracy altogether. The way to save liberal democracy is to protect its core principles – free and fair elections, the rule of law, freedom of speech and association – at the same time as fundamentally changing the way it works.

Deliberative methods could both help renew our ailing democracy and enable us to tackle our biggest challenges: protecting and restoring the natural world and tackling the accelerating climate crisis.

Deliberation involves a group of citizens who broadly reflect the make-up and beliefs of the public spending time hearing and interrogating a full range of opinions and working together to reach shared opinions.

This approach can help iron out the problems with direct democracy. Citizens’ assemblies and conventions have been used around the world to solve difficult problems. In Ireland they helped inform the referendums on abortion rights and gay marriage, and in Texas one increased support for green energy, resulting in the state going from among the worst to among the best in the United States for renewables.

If we had had a deliberative process before the 2016 referendum, I’m pretty sure it would have identified the need for another public vote at the end of the Brexit negotiations.

But there are particular reasons why I think deliberation can help make the case for green measures – and I’m not alone in this. A national citizens’ assembly is one of the three core demands of the Extinction Rebellion, a socio-political movement that is trying to avert climate breakdown.

A citizens’ assembly allows people to explore an issue in depth and understand the choices and trade-offs better. Deliberation helps people see that addressing long-term issues requires hard choices, and helps people to find solutions that work for everyone. I believe the actions necessary to tackle climate breakdown also provide ways to improve people’s lives, but that doesn’t mean we can always avoid hard choices.

The deliberation process delivers ownership, too. People often start by blaming the government, but end up recognising that things are far more complex.

Environmentalism is not something that should be done to the people – it’s something that should be done with people, and ultimately give citizens fresh agency and hope.

If we are to confront the climate crisis while also holding on to our democratic and social values, parliament must urgently establish a citizens’ assembly to draw up a plan of action that has the public’s consent.

British politics is in a state of flux. There is much talk of realignment. But we cannot build a better future through piecemeal change or simply ameliorating the consequences of a broken system.

A country that works for the 21st century – and works for its citizens – will be one that has reimagined its approach to the environment, but also reimagined a fair and cohesive society, reimagined an economy which offers dignity and opportunity, reimagined a powerful and engaging democracy. And reimagined the relationship between all of these too.