If you are located within Sweden, the most climate-friendly way to get to Luleå is by train. The national train operator SJ operates comfortable night-trains from all over Sweden to the northern regions.
Book with SJ: https://www.sj.se/en/home.html
If you arriving from other countries, the best way to get to Luleå is by airplane. SAS & Norwegian operate multiple flights daily from Stockholm Arlanda Airport to Luleå. The city center is a short 10-15 minute drive from the local airport, and taxis are always readily available at the arrival halls.
Book with SAS: https://www.sas.se/en/
Book with Norwegian: https://www.norwegian.com/
There are several hotels to choose from in the Luleå city center. For your convenience, Demo North has reserved rooms at the following hotels: