The amount of carbon dioxide in the air is growing at alarming rates and is now at levels not seen for millions of years, according to the UN.

The dangerous levels of CO2 could fuel a dramatic rise in sea levels and add three degrees to temperatures, its World Meteorological Organisation (WMO) said.

Levels are accelerating far faster than before, with last year’s growth more than 50 per cent above the average for the last decade. That has led CO2 levels to rise 45 per cent above pre-industrial levels and further outside the range of 180-280ppm seen in recent cycles of ice ages and warmer periods.

10 photographs to show to anyone who doesn't believe in climate change Show all 10 1 /10 10 photographs to show to anyone who doesn't believe in climate change 10 photographs to show to anyone who doesn't believe in climate change A group of emperor penguins face a crack in the sea ice, near McMurdo Station, Antarctica Kira Morris 10 photographs to show to anyone who doesn't believe in climate change Floods destroyed eight bridges and ruined crops such as wheat, maize and peas in the Karimabad valley in northern Pakistan, a mountainous region with many glaciers. In many parts of the world, glaciers have been in retreat, creating dangerously large lakes that can cause devastating flooding when the banks break. Climate change can also increase rainfall in some areas, while bringing drought to others. Hira Ali 10 photographs to show to anyone who doesn't believe in climate change Smoke – filled with the carbon that is driving climate change – drifts across a field in Colombia. Sandra Rondon 10 photographs to show to anyone who doesn't believe in climate change Amid a flood in Islampur, Jamalpur, Bangladesh, a woman on a raft searches for somewhere dry to take shelter. Bangladesh is one of the most vulnerable places in the world to sea level rise, which is expected to make tens of millions of people homeless by 2050. Probal Rashid 10 photographs to show to anyone who doesn't believe in climate change Sindh province in Pakistan has experienced a grim mix of two consequences of climate change. “Because of climate change either we have floods or not enough water to irrigate our crop and feed our animals,” says the photographer. “Picture clearly indicates that the extreme drought makes wide cracks in clay. Crops are very difficult to grow.” Rizwan Dharejo 10 photographs to show to anyone who doesn't believe in climate change Hanna Petursdottir examines a cave inside the Svinafellsjokull glacier in Iceland, which she said had been growing rapidly. Since 2000, the size of glaciers on Iceland has reduced by 12 per cent. Tom Schifanella 10 photographs to show to anyone who doesn't believe in climate change A river once flowed along the depression in the dry earth of this part of Bangladesh, but it has disappeared amid rising temperatures. Abrar Hossain 10 photographs to show to anyone who doesn't believe in climate change A shepherd moves his herd as he looks for green pasture near the village of Sirohi in Rajasthan, northern India. The region has been badly affected by heatwaves and drought, making local people nervous about further predicted increases in temperature. Riddhima Singh Bhati 10 photographs to show to anyone who doesn't believe in climate change A factory in China is shrouded by a haze of air pollution. The World Health Organisation has warned such pollution, much of which is from the fossil fuels that cause climate change, is a “public health emergency”. Leung Ka Wa 10 photographs to show to anyone who doesn't believe in climate change Water levels in reservoirs, like this one in Gers, France, have been getting perilously low in areas across the world affected by drought, forcing authorities to introduce water restrictions. Mahtuf Ikhsan

As far as anyone can tell, the world has never experienced a rise in CO2 levels as quick or intense as this. The increase has happened 100 times faster than when the world was emerging from the last ice age.

“Today’s CO2 concentration of around 400ppm exceeds the natural variability seen over hundreds of thousands of years,” the WMO bulletin said.

The latest data adds to the urgency of a meeting in Bonn next month, when environment ministers from around the world will work on guidelines for the Paris climate accord backed by 195 countries in 2015.

The agreement is already under pressure because US President Donald Trump has said he plans to pull the United States out of the deal, which seeks to limit the rise in temperatures to “well below” 2°C (3.6F) above pre-industrial times.

Human CO2 emissions from sources such as coal, oil, cement and deforestation reached a record in 2016, and the El Nino weather pattern gave CO2 levels a further boost, the WMO said.

Scientists know prehistoric levels from tiny air bubbles found in ancient Antarctic ice cores, and they can derive even older data from fossils and chemicals trapped in sediment.

The last time carbon dioxide levels reached 400 ppm was three to five million years ago, in the mid-Pliocene era.

“During that period, global mean surface temperatures were two degrees warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica’s ice retreated, causing the sea level to rise 10-20m higher than that today,” the WMO bulletin said.

Since 1990, the global warming effect of CO2 and other long-lived greenhouse gases has risen by 40 per cent. The two other main gases – methane and nitrous oxide – also grew to record concentrations last year, although at a slower rate of increase than carbon dioxide.