Christiansen participated only briefly in the &lt;a href="Biathlon%20Junior%20World%20Championships%202013"&gt;Junior/Youth World Championships in 2013&lt;/a&gt; in Obertilliach. The championships started for Christiansen with the 10 km sprint event. He shot cleanly, but he finished outside the podium in fourth position. He did not start in the pursuit, nor did he enter any more events in the championships. Christiansen participated in the European Championships the following month. In the first race, Christiansen and his fellow Norwegians were not acclimatized. Thus, Christiansen finished 18th in the 20 km individual, despite missing only once. The next race, the 10 km sprint, was postponed twice due to heavy fog, giving the Norwegians two extra days to acclimatize. This allowed Christiansen to pick up his pace and win the gold in the sprint, shooting clear. The pursuit competition crashed with the men's relay, with the result being that the relay was cancelled. Christiansen won silver in the pursuit, having missed three times, the same amount as the winner, Benedikt Doll.