This is the year when pledges on climate must be turned into action – delay is not an option

French author Victor Hugo wrote: “It is a sad thing to think that nature speaks and mankind does not listen”. Now, 150 years later, nature is no longer speaking to us – it is shouting. And governments still aren’t listening.

Extreme weather events are breaking out all over the world: sweltering heat in North America, mudslides in India, deadly floods in Europe and China, terrifying wildfires in Greece, and the Amazon emitting more carbon dioxide than the forest can absorb.

In the UK, the Met Office warned last month that the extreme weather we saw across the UK in July is now the norm. The impacts of climate change are not something which will only impact future generations, they are here now.

Three months ahead of the UK-hosted UN climate summit, we now have the opinion of the world’s leading climate scientists on the extent to which we have already warmed the planet and set in train those extreme weather events. World leaders, preparing for Cop26, shouldn’t need a reminder of why they need to do far more than their current plans; but if they do, this terrifyingly stark IPCC report provides it.

It shows that the impacts of human activity on the climate are accelerating, whether they be extreme weather events, melting ice caps or sea level rise. Outcomes like ice-sheet collapse, which were given a low likelihood in the last report eight years ago, are now considered real possibilities.

What’s striking about this IPCC report is the blunt language it uses. In the 30 years since the first paper, the language has gone from advising that the impacts of global warming would not be noticeable for a decade or more, to warning that some of the climate changes already set in motion, including sea level rise, are irreversible over hundreds to thousands of years.

That is how fast the climate is changing, and how devastating the impacts are for all of us.

This is the year when rhetoric and pledges on climate must be turned into action plans. Delay is not an option – there is a limited time left to avert the worst impacts of climate change and governments must seize it.

Yet the UK government’s strategy is to cross its fingers and wait in the hope that something will turn up which will get us off the disastrous path we are now on. It sets plenty of targets, but they are rarely followed up with policies for reaching those targets, let alone the necessary investment to decarbonise and transform our economy.

What it should be doing is follow the latest science and respond accordingly. That’s what the Climate and Ecological Emergency Bill, which I introduced in parliament last September, aims to do. The government needs to get on board, fast.

The worrying mood music from the Treasury seems to be that the transition to a sustainable future just costs too much. Yet we know that doing nothing now will mean far, far greater costs in future and will place an intolerable, perhaps impossible, burden on future generations.

The Paris Agreement’s 1.5C target was not arbitrarily chosen. For small island states and other vulnerable countries, it is the difference between their countries still being there at the end of this century or being lost to rising sea levels. But it is also critical for other reasons: the more this limit is breached, the greater the danger of crossing climate thresholds which will set in train potentially devastating changes.

With fewer than 100 days until the Cop26 UN climate conference in Glasgow, there is a huge amount of catching up to do, especially from the UK government. It is actions, not words, which will set the tone in Glasgow, not stale boasts and more targets.

The emissions cuts countries signed up to in Paris must be much more ambitious, yet fewer than half the countries who signed the Paris Agreement have come up with bolder climate pledges. And the world’s richest nations have still not agreed to phase out coal, nor reduce subsidies for oil and gas.

The imperative to leave fossil fuels in the ground is being widely ignored, not least by the UK government which is allowing new oil and gas exploration in the North Sea.

And richer nations have still not honoured the promise they made in Paris to provide $100bn (£72bn) a year to the global south to help those countries address climate change.

The IPCC has been publishing its reports assessing climate damage for over 30 years, each one sounding the alarm bells louder than the last. We’re at risk of going down in history as the species that spent all its time monitoring its own extinction rather than taking the urgent steps necessary to avert it.

It doesn’t have to be that way. If we act now, treating the climate crisis as the emergency that it is, there is still time not only to avoid the worst, but to grasp the opportunity to build a fairer, better world for all of us.

Caroline Lucas is the Green Party MP for Brighton Pavilion