David Attenborough’s documentaries about the natural world have increasingly focussed on the effects of climate change, but none so blatantly – and with such urgency – as his new Netflix documentary-film, A Life On Our Planet.

The film, released to Netflix on October 4 and in cinemas now, is more personal than Attenborough’s usual documentaries, covering his life spent filming with animals since the 1950s – and a sobering story of their decline over one lifetime.

Attenborough uses his own experiences to make the case that if he were born today, and were to reach old age, the world he would witness in 2080 would be a world struggling to grow crops due to the effects of a drastically warming planet.

“We’ve destroyed it, that natural world has gone,” he says. “Human beings have overrun the world… that is my witness statement – the story of global decline over a single lifetime.”

David Attenborough’s documentaries about the natural world have increasingly focussed on the effects of climate change, but none so blatantly – and with such urgency – as his new Netflix documentary-film, A Life On Our Planet.

The film, released to Netflix on October 4 and in cinemas now, is more personal than Attenborough’s usual documentaries, covering his life spent filming with animals since the 1950s – and a sobering story of their decline over one lifetime.

Attenborough uses his own experiences to make the case that if he were born today, and were to reach old age, the world he would witness in 2080 would be a world struggling to grow crows due to the effects of a drastically warming planet.

“We’ve destroyed it, that natural world has gone,” he says. “Human beings have overrun the world… that is my witness statement – the story of global decline over a single lifetime.”

There’s enough gorgeous animal scenery to still make this an enjoyable watch, but it’s also threaded with harrowing images of animals falling victim to our changing climate.

However, it ends with a strong message: we can act now and reverse the damage. Here are six essential takeaways about climate change from A Life On Our Planet.

1. Attenborough remembers it was January 1978 when he first experienced climate change. 

Scenes of Attenborough laying with mountain gorillas during a segment of filming during the 1970s has become iconic, but the clip has been given a dark new meaning as Attenborough revealed it was around this point he first experienced climate change himself.

It was “noticeable” that some of these animals were becoming harder to find due to poaching, he says, which had a knock-on effect to the biodiversity of habitats. “The process of extinction I could see as a boy in rocks [by looking at fossils]… was happening right there, around me,” he says, “to animals with which I was familiar. Our closest relatives. And we were responsible.

“Once the species became our target there was now nowhere on Earth that it could hide.”

2. The derelict city of Chernobyl is an example of how our planet may end up if we don’t act now. 

Attenborough begins and ends the documentary exploring the abandoned school classrooms, family homes and public spaces of Chernobyl – the Ukrainian city that was evacuated in 1986 due to a nuclear explosion.

He warns that the vastly bleak scene-scapes of the city is a plausible reality for our planet if greenhouse gases continue to be released into the environment. These gases cause the destruction of biodiverse landscapes, which store carbon dioxide and keep the planet alive.

3. Our planet is losing its ice. 

“In my time, I’ve experienced the warming of arctic summers,” he says. “We’ve arrived at locations expecting to find expanses of arctic sea ice, and found none. We’ve managed to travel the boat to islands that were impossible to get to historically, because they were permanently locked in the ice.” 

By the time Frozen Planet aired in 2011, he says, the reason for these changes was well established: the ocean had become unable to absorb all the heat caused by our activities. “As a result, the average global temperature today is one degree celsius warmer than it was when I was born,” he says. “A speed of change which exceeds any in the last 10,000 years. Our planet is losing its ice.”

4. Wild animal populations have more than halved since the 1950s. 

Since Attenborough began filming in the 1950s, wild animal populations have more than halved on average. 

Looking at an old, black and white camera reel of these populations, Attenborough says: “I look at these images now and I realise that although as a young man I thought I was out there in the wild experiencing the untouched natural world, it was an illusion.

“Those forests and plains and seas were already emptying.”

5. If we don’t change our behaviour now, it could have devastating consequences on our lives.  

By 2040, frozen soils will thaw, releasing methane into the atmosphere, “a greenhouse gas many times more potent than carbon dioxide, accelerating the rate of climate change dramatically,” says Attenborough.

By the 1950s, as the ocean continues to heat and becomes more acidic, “coral reefs die and fish populations crash”. By the 2080s, 60 years from now, “global food production enters a crisis as soils become exhausted by overuse,” he says, “pollinating insects disappear and the weather is more and more unpredictable.”

And by the 2100s, “our planet becomes four degrees celsius warmer; large parts of the Earth are uninhabitable. Millions of people rendered homeless, and a sixth mass extinction event is well underway.”

But it’s not too late to act…

The thrust of A Life On Our Planet is that it’s not too late to act. Attenborough drills through some of the world-leading climate change solutions and suggests how we can adopt these on a national level. The emphasis is that major corporations must make change from the top, down.

Firstly, we can make renewal power the only energy source, he says: “It’s crazy that our banks are investing in fossil fuel when these are the very things that are jeopardising the future that we are saving for.”

In another segment, Attenborough explains how sustainable fishing is essential. “Fishing is the world’s greatest wild harvest, and if we do it right, it can continue, because there’s a win-win at play: the healthier the marine habitat, the more fish there will be, and the more there will be to eat,” he says.

Restricting fishing and banning it entirely in areas where varieties are endangered has positive effects. “Estimates suggest that no-fish zones over a third of our coastal seas would be sufficient to provide us with all the fish we would ever need,” he says. The EU is planning one such project, which Attenborough calls “the world’s greatest wildlife reserve.”

And, he says, we must change our diet. “The planet can’t support billions of meat eaters – there just isn’t the space,” he says. “If we all had a largely plant-based diet, we would only need half the [farming] land we use at the moment.”

Attenborough adds: “The living world will endure – we humans cannot presume the same. We’ve come this far because we are the smartest creatures that have ever lived. But to continue we require more than intelligence, we require wisdom.”