The extensive floodingin Northern England isjust the latest exampleof extreme weather, not just here but globally. Climate change is becoming a growing threat to food, energy, health,jobs and economic stability as well an increasing factor in mass migration. As December’s COP21 talks underlined, worse is to come if global temperatures rise above two degrees, with land occupied by 280 million people likely to be underwater.

Climate change is a security issue. Given the security of a nation is normally paramount – it’s considered the first duty of government – and climate change poses an existential threat, we should expect leadership and action.

Yet this Government’s head is in the sandbags. At best Ministers talk about climate change action as a nice extra when it can be ‘afforded’; at worst it’s attacked for being ‘green crap’. This shouldn’t be a surprise. Politicians fromthe right still deny the science of climate change, chirpily lambast low carbon measures, yet aresilent on the recent floods.

Ministers are dismantling the Labour Government’s leadershipin passing the landmark Climate Change Act. The DECC Secretary recent leaked letter revealed Britain will miss its 2020 renewables energy target by 25%. The renewables industry is having the rug pulled from under it while the fracking industry is welcomed with a gilded carpet. Solar investment in 2015 dropped to £3.5bn from £5bn the year before due to government changes and cuts to support. The Carbon Capture and Storage trial has been scrapped. Environmental legislation and standards are being axed like the low carbon homes requirement, budgets reduced,and institutions cut or sold like the Green Investment Bank. Ministers flirt with leaving the EU, failingto recognise it’s a bulwark to maintaining and strengthening environmental standards and driving global action. Even policies like the new Marine Nature Reserves (belatedly) announced in January were accompanied by an abandonment of a fishing ban for the most critical areas.

It isn’t just each decision. It also isn’t just about the lost green opportunity: how is buying gas from states like Russia making our energy more secure whenwe could be producing ourown renewable energy? It’s the pervasive short-sightedness: action now costs less than paying for failure later. So what would a progressive government be doing? President Obama is showing leadership. So is Germany: just five per cent of renewables are owned by the big utilities.It is communities, unions and councils that have a stake. Energy is greener, decentralised and democratic, more secure and the changes are enormously popular. Leadership here could bring these benefits alongside improved environments, more sustainable homes using less energy and lower bills, better transport and less pollution, less waste, green spaces enhanced, new jobs, and a global contribution to greater security and a low carbon world.

Using COP21 as a reference, a Prime Minister might give a landmark speech with an honest account of the challenges we face at home and abroad but also the shared benefits of a low carbon path. The idea of a Just Transition, as the TUC has articulated, could be supported. progress points could be identified with independent verification.

Britain could play an active role in global institutions, building alliances to renew them to support effective action. It could be at the heart of the Commonwealth agenda, given its unique membership straddling richer and poorer countries. EU reform could be rooted in an effective response to climate change (surely a better use of political capital than the current renegotiation aimed at pleasing recalcitrant Tory MPs) and it could top the agenda when Britain has the EU Presidency in 2017.

A PM showing leadershipwould champion action across government: purposeful not piecemeal. There could be a credible industrial strategy aligning Britain’s science base, research institutions, businesses and technologies to create and scale low carbon solutions including in energy, transport, and construction. Instead of the No 10 Nudge Unit what about a Low Carbon Ambition Unit? National administrationsand local councils would be engaged as partners in change; communities empowered to drive action from the ground upwards.It was after all local leadership that saw the GLC build the Thames flood Barrier to protect London.

While the PM is shirking his responsibility we are seeing leadership elsewhere. In May, Londoners can elect a Mayor – Sadiq Khan – committed to making the capital a low carbon leader. Environmental progress will feature high in Welsh Labour’s manifesto and Labour local government is driving environmental innovation. They know a low carbon economy isn’t a burden to shoulder but an ambition to embrace. It’s a path to social justice, opportunity, security, and prosperity.