The government that wins the next election stands to govern for half of the decade that the Intergovernmental Panel on Climate Change says we have left to tackle the climate emergency. It will also oversee next year’s international conference on the climate crisis (COP 26) – the most important since the Paris Accord of 2015. We owe it to ourselves and to the world to make sure that climate is not a marginal issue at the election, whenever it comes.

Yet maybe we don’t need to worry. We have largely enjoyed a broad “climate consensus” in this country: we believe in the science, most of us don’t indulge climate change deniers and there is agreement on the need to act. Not for us on this issue – at least so far – the culture wars of the US.

There is a real danger that this sense of consensus creates complacency

But not so fast. There is a real danger that this sense of consensus creates complacency. Of course we should value the fact that both major parties agree on the need to tackle the emergency. We should be pleased that the target of net zero carbon emissions by 2050 was passed without opposition in the House of Commons, and that the Climate Change Act of 2008 passed by a massive majority. We should not create divisions where they do not exist – goodness knows we are a divided enough country as it is.

Yet for all our relative progress as a country, no country, including us, is doing enough to meet the Paris goal, which commits us to efforts to keep warming to 1.5C or below, and no more than 2C. The UK is off track for our targets for the late 2020s and 2030s, and outside the power sector, progress has stalled. We are consumed by Brexit, when next year we will need to strain every sinew and use every resource at our disposal to get 190 countries to agree to toughen their targets so we can get closer to having a chance of meeting the Paris goals.

Every party and every candidate should therefore be asked where they stand on the key questions that face us – not just on warm words and good intentions but on the actions they are willing to take and support. What is your vision for tackling the climate emergency? Are you willing to be consistent in the decisions you take so climate is not simply an add-on? Are you willing to commit to the urgency required?

On vision, it is obvious to me – and I believe to the Labour party – where we need to go. As I have written before, avoiding the nightmare only takes us so far. We need to spell out the dream, encapsulated in the phrase the Green New Deal – so we meet concerns about economic justice and the climate emergency together. That’s about creating millions of jobs as we change the way we power our country, heat our homes and travel around. We also need to redesign our towns and cities and rethink the way we use our land, improving quality of life as we do. Every party should be tested on its plan to meet this vision, or an alternative, and how they will pay for it in a way that is fair.

Next comes the need for consistency of purpose and singularity of focus on this issue. It is no longer enough to have some “green policies”. In a world where we move to zero carbon, every policy must be green. Of course there is a transition, and the transition must be fair for the workers affected, but there must be a framework that doesn’t simply ignore the problem. For instance, going ahead with the third runway at Heathrow without any sense of how that is consistent with this framework will undermine the public’s trust that we are serious.

Finally, there is the issue of urgency. Labour’s conference decision to aim for net zero by 2030 is controversial. With today’s politics and the challenges of transition we face, it feels like a moonshot. But Apollo-level ambition, imagination and determination is exactly what we need.

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There is reason to hope that we can achieve more than looks possible at present. Climate “tipping points” are generally about uncontrollable negative feedback loops. But there are positive tipping points, too. We have seen this with the costs of solar and wind tumbling far faster than anyone forecast, driving much higher take-up than anyone expected. After initial support by government, these technologies now make an unanswerable economic case on their own merits.

Whatever the level of reductions by 2030 to which different parties commit, we need a totally different level of commitment by government not for 2050 but for the next decade. It is now five months since parliament passed the climate emergency motion, and apart from the net zero target for 30 years’ time, government has done nothing to show it gets what an emergency means.

If an election comes soon, Brexit will be the dominant issue. But the climate emergency matters even more to the long-term future of the country. That future depends on decisions made in the next five years. Consensus on the need to act matters. But to save the planet, we need an arms race on speed, scale and urgency.

• Ed Miliband is MP for Doncaster North and a former climate change secretary