[MUSIC] So, why do mountains matter? Mountains are of critical importance to people in nearly every country on the planet. Whether we know it or not, mountains impact most of us. Mountains comprise one-quarter of the world's surface and over a quarter of the world's human population lives within or very close to mountainous areas but their impacts are everywhere. Let's start by considering the various services and resources that mountain ecosystems provide for us. Almost all of the world's major rivers have their head waters in mountains. More than half of the world's population relies on the fresh water that collects in mountainous regions, whether it's for drinking water, domestic use, irrigation, industry, or transportation. Hydro power from mountain water sheds make up nearly 20% of the world's entire electricity supply. Mountain forests provide millions of people with timber and other products. Mountain forests also play a vital role in capturing and storing rainfall and moisture, maintaining water quality and regulating river flow and reducing erosion and downstream sedimentation. The same geological forces that have raised mountains up, have also helped to concentrate assemblages of minerals and mountain mines are a major source of the worlds ores and precious metals. >> Mountains are hot spots for biodiversity, this means they provide habitats that support and sustain a large variety of different species, from plants and animals, to tiny invertebrates, and microbes. With increasing altitude, changes in temperature, moisture in soils can create a dense juxtaposition of differing ecological communities. They can range radically from dense tropical jungles to hard, glacial ice within just a few kilometers. Many mountains can be thought of as islands that rise above the vast plains of human transformed landscapes below. Many plants and animals are endemic to mountain regions, having evolved in isolation over millennia to inhabit specialized alpine environments. Many mountain ranges also function as biological corridors, connecting isolated habitats or protected areas, and allowing species the critical space they need to migrate and thrive. In Western Canada, the Rocky Mountains provide the large wild spaces that support populations of grizzly bears and other large carnivores. Mountains can also provide sanctuaries for plants and animals, long since displaced from the more transformed lowlands. Take for example the volcanoes of the Virunga Mountains along the border of Rwanda in East Africa. It's here where the last of the world's mountain gorillas, now numbering fewer than 300, can still be found. Biological diversity is often linked to cultural diversity and mountains have hosted an incredible diversity of human cultures and communities. For instance, of the 1,054 languages spoken in New Guinea, 738 originate in the New Guinea highlands, which cover 30% of the South Pacific island. Around the globe, mountains are home to many indigenous peoples, the long-time inhabitants of a place before the arrival of other peoples in more recent times. Like the Quechua people of Bolivia, Ecuador, and Peru in South American Andes, the Southern Tuchone First Nations of the southern Yukon in Canada, the Nakhi and Yi people of Hunan Province, China, or the famous Sherpa peoples of the Mount Everest region in Nepal. Many of the world's most important food staples like potatoes, wheat, corn and beans were domesticated in mountains. Industrious mountain people, long ago developed elaborate agricultural production systems and strategies, based on altitudinal and ecological zonation. Many of these systems are still in use today. >> The physical and cultural make-up of the world's mountain regions is a major draw for global tourism. Tourism is one of the world's largest and fastest growing industries and tourism to mountains represents a significant portion of this activity. Visitors go to mountains for all sorts of reasons, for adventure, for sport and recreation, to enjoy scenic beauty or solitude, or for the opportunity to meet and interact with the people who live there. An influx of mountain visitors can have a positive economic benefit for mountain communities, like helping to promote sustainable development. The capacity to balance human needs with the preservation of the environment. However there is also the potential for negative environmental and cultural consequences, such as the impacts of large numbers of people on fragile mountain ecosystems and the loss of traditional cultural values. Mountains have extraordinary cultural significance to peoples from different cultures all around the world. For some, mountains have become places of national embodiments, places in which citizens feel patriotic. Mountains are sites to be used to be exploited and developed for their natural resources but also the many leisure opportunities that they provide and support. They're islands of wilderness to be saved, to be protected and set aside. They are also sites to be managed and controlled. Sometimes there are obstacles for trade and commerce. Mountains are places to be feared, they're testing grounds, arenas for competitions and sport. They're places for salvation, embodiments of divine serenity, sometimes Godly wrath. Mountains have served as sites of redemption, places of restorative health. For many, mountains are home and for others they're a destination to visit. The mountain world can be all of these different things to different people, making them places of extraordinary possibility. While the mountain world can be many different things to many different people, mountains can also be sites of great exclusion. In many parts of the world, they can be places of debilitating poverty, places on society's margins where communications are poor and infrastructure, jobs, and services are sorely lacking. The complex topography of mountain regions and the often high frequency of natural hazards, things like avalanches and landslides, floods and earthquakes, compound issues related to poverty. Conversely, mountains can also be places for only the global rich. Gentrified playgrounds for urban holiday-goers, where locals are increasingly finding themselves unable to afford the very places where they grew up. And now, hardly recognized due to foreign investment and hyper development. These are just some of the challenges facing these very special landscapes, we'll examine these and many more as we proceed.