International Mountain Day 2018: What's this year's theme and why we need to protect mountains

They serve as spectacular backdrops to some of the world’s most scenic areas, and once a year the United Nations marks our appreciation of them with International Mountain Day.

Designated by the UN in 2003, the commemorative day is intended to draw attention to the importance of sustainable mountain development and mountain communities.

The UN website states: “Almost one billion people live in mountain areas, and over half the population depends on mountains for water, food and clean energy.

“Yet mountains are under threat from climate change, land degradation, over exploitation and natural disasters, with potentially far-reaching and devastating consequences, both for mountain communities and the rest of the world.”

Here’s what you need to know about International Mountain Day:

When is International Mountain Day?

International Mountain Day falls on December 11 every year.

What's the theme for this year's International Mountain Day?

The theme for this year is #MountainsMatter, taking a closer look at the “crucial role [mountains] play in providing key ecosystem goods and services to the planet and their vulnerability in the face of climate change, we need to step up and raise attention to mountains.”

People all over the world are being encouraged to use the hashtag #MountainsMatter on social media specifying why mountains matter to them.