I know exactly how we can solve our environmental crisis – and it all starts with this one simple law

We don’t throw a family member onto the streets because they have ceased to be of economic value. Similarly, we don’t spend everything we have today so that our children have nothing tomorrow

We are at a turning point in the battle to rescue ourselves from climate disaster. The Youth Climate Strikes have inspired a whole new generation, Extinction Rebellion has brought the crisis to the gates of Westminster, 16-year-old Greta Thunberg has told the government in no uncertain terms what it needs to do – and now MPs have declared a climate emergency.

New voices are bringing fresh light to the most pressing issue of our time, and with it some hope, but the reactionary forces that fear any change to business as usual will be regrouping and rallying to defend old interests – and to crush that hope.

So while Thunberg may have returned home and the positive creativity that transformed Marble Arch and Waterloo Bridge has moved on, we must find ways to keep the energy and urgency of recent weeks alive. The demand for action is clear, the need beyond doubt. If we lose our nerve now, future generations will never forgive us.

That is why I am pushing to create a groundbreaking new law and introduce the world’s first Compassion Act which would completely shift the dial on the current political debate – to put inequality and climate breakdown front and centre of the agenda for the coming years.

The law, developed along with the campaign group Compassion in Politics, would prevent any future legislation being introduced if it will leave those in the most vulnerable circumstances worse off, or if it benefits current generations at the expense of future ones.

These may seem like fairly commonsense goals and that is because they are. They are aligned with the values most of us try to uphold in our home and family lives. We don’t throw a family member onto the streets because they have ceased to be of economic value. Similarly, we don’t spend everything we have today so that our children have nothing tomorrow.

Yet the new economic agenda has left politics divorced from these values for far too long. It has legitimised greed, lauded limitless growth, promoted overconsumption and, courtesy of Brexit, fed and fanned the flames of hate. It has sidelined the values most of us hold dear like honesty, decency and compassion. Our political system has hit a spiritual as well as a physical rock bottom.

Today, along with the MPs Heidi Allen, Jo Swinson, Thangam Debbonaire and Tracey Crouch, I will be discussing this proposal in parliament. We have an opportunity now to regain the world leadership we have lost. The climate crisis exists because, for decades, we’ve behaved with little or no regard for the world our children and grandchildren will inherit. We have chosen business as usual and immediate gratification over a safe planet where all life can thrive. Similarly, years of austerity and ideologically driven privatisation have left the social contract which once bound the government to its people in tatters.

We think it’s time to rewrite that contract and we’re going to make sure it extends to our children and grandchildren. In doing so we want to carve out a role for Britain as a progressive leader on the world stage – setting an example that others will hopefully follow. The crisis that we face right now is not unconquerable: it’s been made by humans and it can be solved by us. Becoming the first country to put a Compassion Act onto the statute books would show us to be world leaders in the most positive way possible, and be something of which everyone could be proud.

If we don’t protect what we value most, we will lose it. A Compassion Act would create a threshold below which this country could not fall again. It would help protect against the shameful rise of homelessness, hunger and degradation that the most disadvantaged in our society have experienced. And, it will provide a constructive mechanism for immediately starting to address the climate emergency.

After years of austerity and environmental vandalism, and at a time when public trust in politicians is dangerously strained, we believe that a Compassion Act could play a vital role in steering the British political system on to a more inclusive, compassionate and positive path.

Caroline Lucas is the Green Party MP for Brighton Pavilion