From wildlife trafficking in West Africa to visualising the internet of the future, here's a festive selection of the best science and environment long reads published on the BBC this year. You can read part two tomorrow.

The secret trade in baby chimps. By David Shukman and Sam Piranty

Image caption Nemley Jr, the infant rescued from traffickers after the BBC investigation

David Shukman and Sam Piranty undertook a year-long BBC investigation into the secret network of wildlife traffickers selling baby chimpanzees. The trail led to a West African hub for wildlife trafficking and to the rescue of a one-year-old chimp, named Nemley Jr.

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Climate's magic rabbit: Pulling CO2 out of the air. By Matt McGrath

Image copyright Climeworks Image caption Air is sucked through fans and CO2 extracted via filters

In 2017, reports indicated that concentrations of carbon dioxide in the atmosphere had broken records while international attempts to curb greenhouse gases were not doing enough to avoid dangerous levels of warming. Could technology to remove CO2 from the air provide an answer to the ongoing carbon conundrum?

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'Our Saturn Years': Cassini's epic journey. By Paul Rincon

Image copyright Getty Images Image caption Artwork: Saturn and its rings

The Cassini space mission ended in September 2017, after 13 glorious years exploring Saturn and its moons. To mark the controlled destruction of the spacecraft in Saturn's atmosphere, the BBC told the story of the mission through the experiences of those who made it happen.

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When we discovered how the Earth really works. By Jonathan Amos

Image copyright The Geological Society, McKenzie Archive Image caption Dan McKenzie: The young scientists of the 1960s sought answers that had eluded their elders

What would you put on your list of the great scientific breakthroughs of the 20th Century? One discovery that ought to be on everyone's rundown is plate tectonics. The theory is just 50 years old, yet it provided the first convincing cause for volcanoes and earthquakes.

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Building the next-generation internet. By Mary-Ann Russon.

Image copyright Getty Images Image caption Scientists are now developing an ultra-fast quantum internet that will be partly based on light

Super-fast "quantum computers" are being developed in laboratories around the world. But how will these next-generation machines interact? Scientists are already thinking about a light-based quantum internet that will be as fast as the computers themselves.

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Trump's divided desert: Wildlife at the border wall. By Victoria Gill

Image caption How would building a wall along the US-Mexico border impact species?

President Trump's vow to build a "great wall" along the US-Mexico border remains one of the most controversial promises of his presidency. Scientists are starting to unravel the effect that such a wall could have on a desert ecosystem it will cut through. The team is studying wildlife in the Sonoran Desert, which is already divided by a barrier at the border.

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The power of a billion: India's genomics revolution. By Kat Arney

Image copyright Getty Images

Could an effort to gather genetic data from its population of one billion people help India take the lead in advanced healthcare?

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