Whether it's young people taking time off school or the Commons' naked protestors: they are right. We face a climate crisis.

Liberal Democrats should provide the emergency plan. In 3 parts.

• UK-wide action to green ourselves.
• Action to decarbonise capitalism - starting with the City of London.
• And an international green new deal - where richer countries support poorer countries.

Starting with the UK - Lib Dems have shown we can decarbonise and prosper. Thanks to achievements in Government on renewable energy and what many Lib Dem-led councils have done in their communities, the benefits of climate change action are proven.

Renewable energy erodes the power of the likes of Vladimir Putin and the Crown Prince of Saudi Arabia

I fought huge battles in Cabinet - against the likes of George Osborne and Eric Pickles. But we won. Lib Dem Energy Ministers nearly quadrupled Britain's renewable power- and now we're the global leader on offshore wind.

Plus our policies led to clean power prices plummeting - so renewables are cheaper than gas and nuclear. And the economic benefits are now indisputable - look at the huge boost to Hull, with the 1,000 jobs created by Siemens' investment in a wind turbine factory.

Yet Conservative policies have since slashed investment in Britain's renewable energy. We must reverse this and accelerate action to reach net zero carbon as fast as possible. Green technologies are there in abundance. But it needs strong political leadership, on everything from tidal lagoons to a hydrogen economy.

For voters, our promise could be "Your Home, Your Power Station" - where we help people generate, store and even sell their own power and heat.

View image on Twitter

The emergency plan's second part - decarbonising capitalism - is a project I've been working on for three years. By forcing global finance to take climate risk seriously we could catalyse trillions of pounds of private capital to flow out of fossil fuels and into clean energy. This could power emergency green investment and embed climate action into global capitalism.

The policies for this are radical - but practical. We should force banks, pension funds and stock exchanges to take climate resilience tests - like the "banking stress tests". Overnight, it would require transparency over their fossil fuel assets, let investors know the true risks and allow regulators to consider penalties. And the public should have more say where our pensions are invested - so we know how green our own savings are.

And radical is credible here. I'm engaging on this with everyone from the International Energy Agency to Mark Carney, Governor of the Bank of England: we're pushing at an open door.

This could unlock hundreds of billions for the UK's climate effort - turning every bank into a Green Investment Bank!

Lib Dems have shown we can decarbonise and prosper

Emergency plan part 3 recognises the UK can't tackle climate change alone - and that Brexit is a disastrous idea.

For 3 years, I led Britain's "climate diplomacy" - setting up a "Green Growth Group" of European Ministers. Thanks to that work, the EU adopted more ambitious targets for cutting greenhouse gases. We took them to the United Nations and ultimately produced the critical Paris Climate Treaty.

Climate diplomacy, know-how and green trade policies can now go further, especially given recent greening in China and India, where one third of humanity live. With vast supplies of ultra-cheap sun and wind power, we should now aim for a global Non-Proliferation Treaty on Fossil Fuels. And end exploration for coal, oil and gas, for ever.

The prize if we help poorer countries isn't just defeating the climate change that affects us all.

We can also tackle global poverty - with cheap solar to bring electricity to the world's rural poor for the first time - and improve the world's health by cutting air pollution.

Plus we can give peace a chance: renewable energy erodes the power of the likes of Vladimir Putin and the Crown Prince of Saudi Arabia - weakening tyrants and eliminating the control of oil supplies as a cause of conflict.

So let's campaign for an emergency plan for the climate crisis - and win a greener, safer and more prosperous world.