Think Mersea Island in Essex – only in the Pacific: beautiful beaches, low horizon, wading birds, seafaring folk. Now imagine the low-lying land where the highest tides become dangerous events: homes inundated by the encroaching waves. As the saltwater intrudes into the soil, the crops are poisoned; graves are washed away, lost forever to the sea.

It’s tough for the community to recover. It used to be maybe twice a year. Now high tide follows high tide with increasing regularity. Then today arrives: Monday 8 October, 2018. A remote group of the world’s top scientists publishes your death warrant. In 22 years’ time your home, your community, your children’s school, your entire island will be under water. Lost.

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Today's death sentence is not for Mersea Island. It is for the Marshall Islands and dozens of other vulnerable low-lying communities in countries like Bangladesh, Pakistan and the Philippines. Places where millions of people live and from where they will have to move as sea levels continue to rise and climate catastrophes such as typhoons and hurricanes become more frequent and more severe.

Today’s report from the Intergovernmental Panel on Climate Change (IPCC) is explicit. Without major political change, the Paris Agreement target to stay below a 1.5C rise in global warming will not be met. All the promises by countries to cut emissions are just not enough. In fact, we will break the 1.5C barrier by 2040 and hit a catastrophic 3C rise by the time a child born today has lived to see 70.

Even the real Mersea Islanders of Essex will be affected. Such a wholesale dislocation of millions of people elsewhere in the world would create frontiers of conflict, a refugee crisis the likes of which we have never seen and disruption of manufacturing and supply chains that would impact every part of the world economy.

The report has set out just what staying successfully within 1.5C means. The IPCC has concluded that by 2050, the world must be carbon neutral: emitting, on balance, zero greenhouse gas emissions. That requires the phaseout of fossil fuels and the mass deployment of solar and wind energy – globally, and at a pace and scale never seen before.

The international scientific community is calling for an instant step-change in our approach to tackling climate change. Its findings are unequivocal about the urgency and depth of action needed. The report says that only “rapid and far-reaching” changes to the world economy will suffice.

In practice this will mean investing billions into a low-carbon economy and green technologies. Mersea Islanders already have the Gunfleet Sands and the London Wind Array off their shore, but the economic programme now required will have to unlock a dramatic sevenfold increase in offshore wind farms by 2030.

The effective ban on onshore wind by this government and their cuts to photovoltaic solar panels will have to be reversed to unleash the country’s full renewable energy potential, so that in just 12 years we will see 6,000 more wind turbines onshore. In that same timespan, we will need to insulate 12 million homes to high energy efficiency standards.

These parts of our green transformation strategy will create more than 400,000 high-quality jobs in the low-carbon economy. It will be the most far-reaching programme of investment and transformation Britain will have seen in decades. And it will achieve a 60 per cent reduction in emissions by 2030, putting us firmly back on track to meeting our carbon reduction targets. And these policies are precisely what Jeremy Corbyn and Rebecca Long Bailey announced in their Liverpool Conference speeches.

But that’s only a stopping point towards Labour’s ultimate goal: net zero greenhouse gas emissions before 2050. It is a hugely ambitious target. It’s also the only one that has any hope of keeping our planetary home fit for human habitation. There can be no doubt about the direction of travel. That’s why New Zealand has set a net-zero greenhouse gas target for 2050, and Sweden has gone even further with an ambition to get there by 2045.

Even the Marshall Islands have now pledged to reach net zero by the middle of the century. In the words of their prime minister: “If we can do it, so can you.”

The UK has the natural skills and natural resources to be leading the world in this transformation. All it currently lacks is sufficient political ambition and investment from government. A good example is where the UK signed up to the Carbon Neutrality Coalition – a group of nations committed to adopting net zero targets – yet without ourselves having adopted a net zero target. This is just cheap talk. It reeks of a government too cowardly to take the bold steps that the scientific evidence demands.

The government should steal Labour’s ideas. I hope they do – it’s the right choice for both our economy and our environment. By investing in this transformation we can create thousands of high-skilled, well paid and unionised jobs. Sadly this government’s record on climate change is dismal: annual investment in clean energy is at its lowest level since 2008.

The government has ignored repeated warnings that we are still miles off meeting our legally binding climate targets, refusing to do anything to correct our course. This summer, coal has even made a comeback. There’s now a real risk that the UK’s emissions from the energy sector will start rising again, undoing years of progress – and casting doubt on whether this government will keep their vow of getting rid of coal power by 2025.

It feels like we are going backwards. The IPCC report from the world’s climate scientists does not mince its words: we need immediate, radical action. But first we may need a Labour government that has the vision and the bold policy to deliver it.