There's a lot going on here: First of all, Jesper Tjäder is shredding an artificial ski slope. While we wouldn't say that his skiing here eclipses Unrailistic, it's still Tjäder-quality. However, skiing isn't really the centerpiece of this video. Instead, the slope itself and what lies beneath are the most interesting parts.
CopenHill is a structure with numerous functions. It has an artificial ski slope on the roof, and sport-climbing routes are planned for its facade. Aside from recreational value, it also houses a co-generation and integrated waste-management facility. 400,000 tonnes of processed waste per year provides 60,000 households with heat, 30,000 households with electricity, and produces 100,000 tonnes of ash for use in road construction.
The plant is part of Copenhagen's plan to become carbon-neutral by 2025, working alongside other renewable energy sources and sustainability initiatives in an attempt to reduce the metropolis' impact on our global climate. For more information on the design of and philosophy behind CopenHill, see the above video.