For too long humanity has been sleepwalking towards a future that risks being defined by chronic food and water insecurity, with millions displaced as a consequence of climate change. As the years have passed the world has been getting hotter with increasingly devastating consequences. The powerful storms, droughts and floods we are seeing more regularly are the direct consequences of unchecked global warming.

Recent research from Unicef has shown that rising temperatures increase the risks of conflict. Our own Ministry of Defence has warned “Migration is likely to increase, with people moving within, and outside, their country of origin to seek work or to escape the effects of climate change.”

The Governor of the Bank of England, Mark Carney, has warned it could also impact our economy too. He said, “Once climate change becomes a defining issue for financial stability, it may already be too late.”

Next week, governments from across the world will gather in Paris to address this threat – the most significant humanity will face in the 21st century. We now know that there is a 50 per cent probability that if we continue our economic development unchanged – dependent on fossil fuels – it would lead to six or seven degree warming over the next century.

Addressing this threat is such an enormous responsibility that no leader anywhere deserves the name unless they are doing everything within their power to avert that possible future. Yet the sheer scale of the risk should not dent our optimism. So far 160 governments representing 95 per cent of global emissions have committed to cut their carbon pollution and switch to using cleaner, more efficient energy sources. That is significant progress on where we were even a few years ago, when world leaders last met to try and reach a climate agreement in Copenhagen.

If these national pledges are supported by effective monitoring systems, and mechanisms for raising our collective ambition every five years as cleaner technologies continue to fall in cost, the world will have finally found a joint approach to respond to the looming crisis.

But the Paris summit should be about more than negotiations between governments. It should be an opportunity to mobilise people power to help solve the challenge. Tomorrow, I will be joining the People’s March for Climate, Justice and Jobs in London to call for unity. Too often we have allowed climate change to become a cause of division.

We are told that to achieve a cleaner economy, jobs must be axed and working families must pay; or that we must choose between protecting the welfare of workers at home and addressing the impoverished condition of billions overseas.

Do not believe that rhetoric. A greener world can also be a more just, more equal and fairer world. To tackle climate change, we must address growing global inequality and show that defeating the menace of global warming will not only improve the prospects of our children and grandchildren but will improve lives here and now.

Britain should be at the fore of the global effort to address climate change at Paris, but our diplomacy will only be effective if we are leading by example. We must show that working families in polluting industries can be protected in the transition to a low-carbon economy by investing in the skills and technologies we need to take advantage of the millions of new jobs the low-carbon sector can create.

The Tories are taking us backwards. They present cutting emissions as a burden we should roll back from. They are cutting support for green industries like our important solar businesses, privatising the Green Investment Bank, and imposing fracking on communities without the environmental safeguards in place the same ministers used to say were necessary.

The Labour Party will show – in our words and deeds – that we can both shape a more just world and build a cleaner economy. We were proud to pass the Climate Change Act, to make Britain the first country in the world to have a legally binding framework for reducing emissions.

This week more than 50 Labour councils, coordinated by the shadow energy and climate change secretary Lisa Nandy, were proud to pledge their commitment to create a clean energy boom across our towns and cities. This will be both a huge economic opportunity to create jobs, but also give communities more of a stake in our energy system.