Breaking Boundaries: 10 of the most surprising facts from David Attenborough's Netflix documentary

Breaking Boundaries: The Science of Our Planet is available on Netflix from June 4^th.

Here are 10 fascinating facts revealed in the documentary.

The planet’s temperature stabilised only 10,000 years ago.

The period of stability is called the Holocene, and it is when the planet’s temperature only varies by plus or minus one degree Celsius. In this period, sea levels stabilised, there were predictable seasons and reliable weather, all making civilisation possible as man could grow crops according to the climate.

We’re not in the Holocene anymore.

Unfortunately, this stable period has ended and scientists have now declared we are in the Anthropocene, the age of humans, because we are now the primary drivers of change on Earth, turning half of the world’s habitable land into areas where we grow plants and raise livestock, and also fishing half the world’s oceans.

Scientists have worked out what boundaries we need to set ourselves so we don't threaten the Earth’s stability.

The first high risk boundary is the Earth’s climate, and the rise in temperature can be easily measured by looking at the world’s ice. In Rockström’s native Sweden, the glacier at Kebnekaise made it the highest peak in the country. However, it has been shrinking at approximately a rate of half a metre per year for the last 50 years and no longer holds that title. Rockström's main concern is the two caps of permanent ice at Antarctica and the Arctic – they need to stop melting for the planet to remain stable.

It’s too hot in Greenland.

Greenland, in the current climate, is already beyond its threshold for heat. Due to climate change, the country is losing 10,000 cubic metres of ice per second and this will continue as the climate heats up. Unless we can cool the planet, the melting of the Greenland ice cap will continue, eventually raising sea levels around the world by seven metres, threatening coastal cities.

The greenhouse gases boundary was crossed back in 1988.

The Earth’s temperature is linked to the concentration of carbon dioxide in the atmosphere. This was reasonably steady until the Industrial Revolution, and by 1988 the Earth passed 350 parts per million (PPM) of carbon dioxide in the Earth’s atmosphere. Since then, we risk changes that could cause runaway warming. The level is currently 415 parts per million – beyond 450 PPM is considered highly dangerous.

As well as climate, there are four other boundaries that have already been exceeded.

These include land configuration, which is keeping the important natural habitats we need to survive such as rainforests, wetlands and grasslands. The second boundary is biodiversity – retaining all the species in water and on land – and the third is protecting what Rockström calls the bloodstream of the planet, the fresh water. The fourth boundary is maintaining the nutrients we need, the nitrogen and phosphorus that is on the planet.

UK scientists were so desperate they stole bees.

One million species of plants and animals out of an estimated total of eight million are threatened with extinction, according to the documentary. By the 1990s, the short-haired bumblebee, one of the best pollinators for food crops, was declared extinct in the UK. Rockström says there were reports that UK scientists went to Europe – including his native Sweden – and stole hundreds of short-haired bumblebee queens to reintroduce them to the country.

We need around 3,000 litres of fresh water per person per day to stay alive.

Fifty litres of this is for hygiene and drinking, while the developed world uses an additional 100 litres for household needs (like clothes washing) and industry needs a further 150 litres a day. The rest – more than 2,000 litres – is needed for our food – to water and nurture the plants that both people and animals need, and also for the animals we eat to drink.

The chemistry of the ocean has changed.

According to the documentary, around one third of carbon dioxide emissions end up in the oceans. This has changed their chemistry, making the oceans more acidic, which effects what grows there, such as molluscs and other sea life.

Three of the five biggest bleaching events of the world’s coral reefs have occurred in the last five years.

Corals bleach when the waters around them get too warm, which is happening due to global warming. Scientists worry about the narrowing gap between bleaching events, as the corals need a chance to recover – it is estimated that half of the Great Barrier Reef’s corals have already died.

Breaking Boundaries: The Science Of Our Planet is on Netflix from Friday, 4^th June. If you’re looking for something else to watch, visit our TV Guide or check out our Documentaries hub for all the latest news.