Of course there is no ‘Planet B’. That's why I'm declaring a climate emergency – but will my fellow MPs admit it?

If MPs pass Labour’s motion today, we will become the first parliament in the world to have recognised this sobering truth

A 16-year-old Swedish schoolgirl, Greta Thunberg, gave British politicians a lesson in clarity and truth last week. Our greenhouse gas emissions are not falling fast enough to avert catastrophic climate breakdown. Our wildlife is vanishing before your eyes, with species levels nosediving towards extinction. “This ongoing irresponsible behaviour”, she scolded, “will no doubt be remembered in history as one of the greatest failures of humankind.”

She’s right: we are in the midst of a planetary crisis. But we are acting as if the scientific evidence does not matter. We talk about what is politically possible when we should only be talking of what is scientifically required.

At the other end of the age spectrum, in his recent BBC documentary, Climate Change – The Facts, David Attenborough explained to millions of viewers that we are facing irreversible damage to the natural world and the collapse of our societies.

It is because of this immense scale of disaster we face that this Wednesday, Labour will ask parliament to announce an environmental and climate emergency.

If MPs pass Labour’s motion, we will become the first parliament in the world to have recognised this sobering truth.

This would be the boldest demonstration yet of Britain’s commitment towards taking environmental breakdown and climate chaos with the seriousness and urgency that scientists have shown it needs.

And doing so would inspire countries everywhere to follow suit and recognise the scale of the problem we are dealing with. That is what happened when the Labour government was the first to legislate for emissions reductions targets in the ground-breaking Climate Change Act in 2008: it became a model for the rest of the world.

It is also fitting that the UK should take such a lead, because we were the first to usher in the era of coal power with the industrial revolution, making us one of the largest global contributors to climate change.

In fact, since 1750, the UK has produced 77 billion tonnes of CO2 emissions, making us the 5th largest polluter of all time. So, the least we can do is to take responsibility for our part in creating the problem.

Government ministers say that there is no point in declaring an emergency. They say it is actions that matter. But if you do not accept that there is an emergency you will not act as if there is one.

Under Labour’s plans for a Green Industrial Revolution, ending the emergency will also make economic sense. Our existing plans to invest in new solar and wind energy, and to retrofit existing homes, will create at least 400,000 jobs across the country – with the potential for many more.

We are global leaders in technologies like renewable wind power and we must not allow those workers in the old oil and gas industries to lose out when the world moves away from fossil fuels to the clean energy of the future. That is why Labour is so committed to a just transition that will move people gradually into high-quality, well-paid clean jobs.

People will only embrace the radical transformation we need it if they see it is working for them as well as for future generations.

But if we are to have a policy to achieve net zero domestically, then we must not undermine it with what we do overseas. It shows an utter lack of the coordinated thinking we need that this Tory government is currently spending 99.4 per cent of our export finance for energy on supporting fossil fuel projects overseas.

Research published this week shows that all of the forecast $4.9 trillion of global investment in new oil and gas fields is incompatible with limiting warming to our Paris commitment of 1.5°C.

The government cannot continue investing in fossil fuels overseas – a policy so egregious that even the former UN secretary general Ban Ki-Moon has called on the UK to change course, “in the interests of the whole world”.

We only have one world. But we are consuming its resources and polluting it so badly and so fast that we are in danger of bringing about our own extinction. We must act not as politics allows but as the science demands. There is no plan B and no Planet B.

Labour believes the British people have the common sense and the vision to show the world a way out of this crisis.

But as with any problem, the first step is in recognising it for what it is. That’s why parliament must declare an environmental and climate emergency.

Barry Gardiner is MP for Brent North and the shadow international trade secretary