Much of his work derives from exploration, primarily through walking. His ‘Datascapes’ Series involve collecting specific data on walks; the length, the pace, the altitude or number of steps etc. and translating the data into a painting which become physical representations of the momentary act of walking itself. These ‘potential landscapes’ are also paintings of time and distance and it is these additional spatial and temporal qualities that he is keen to express, whether through constructed landscapes or from a direct observation of the environment. They act as a record of both the activity of the artist in the landscape but also in the studio. What once might have been described as homage to the environment has now become something more adversarial, with each body of work beginning to question the value of human activity; whether this is the construction of our cities, our stewardship of the environment or the role of the artist as a witness and how this can be expressed in his work.

He is a Fellow of the Royal Geographical Society (with IBG) and co-founder of The Wilderness Art Collective, bringing together a diverse range of artists from across the UK who’s work explores the Landscape and Environment.

He was the first Artist in Residence at Bankside Hotel, London from November  2018 - February 2019, where he made a series of walks from the residency space and painted the locality, a site undergoing immense change.

Walker was also recently invited to jointly exhibit in Taichung, Taiwan with Wan Lin Chang, in ‘Travels of the Mind’ a show at Zasso Gallery in which both artists have created paintings from memories of cities visited.