Johnsen was educated at the royal art academy in 1939. He was especially known for his dark powerful landscapes from Jutland and Rösneas. Johnsen was a very sensitive and passionate artist and he often used his art to express his famous strong temper. Johnsen experimented a lot with lights and shades and preferred painting by sunset or sunrise so he could work with natures own dark and bright colors. Johnsen worked mostly with Modernist Danish landscapes until in 1950 where he traveled to France to paint.
The Artists Fall Exhibition: 1931-1944
Danish art, Sweden: 1950.
Nord, Sweden: 1950.
Gallery Birch: 1953.