Here are some of the words and phrases the BBC encountered this year that helped to unravel the changes taking place in world around us.

Equatic is among a wave of start-ups exploring how the ocean could be harnessed to capture and store carbon. But not everyone is sure it's such a good idea.

Global temperatures rose and extreme weather ramped up, but there were also some significant breakthroughs for the climate this year.

The Boiling River regularly reaches 86C – with drastic consequences for the surrounding rainforest.

Skiers, climbers, cyclists and even mushroom-pickers face surprising new risks in the mountains – and so do those who rescue them.

Reaching the geothermal energy far beneath our feet will require digging further into the Earth's crust than ever before.

The environmental pros and cons of Christmas trees go far beyond the climate impact of "real or plastic", scientists say. So what's the best choice for a green Christmas?

From erecting seawalls to selling citizenship, vulnerable small islands are taking sometimes drastic measures to protect themselves from rising seas, storms and economic devastation.