Born in Manchester, England, Cohen was educated in Jersey at Moorestown, St. Michael's Preparatory School, Victoria College and then studied accountancy at London South Bank University.

During this term he introduced the Eco-Active environmental awareness campaign, introduced Percentage for Art, established the Renewable Energy Commission, established the Jersey Architecture Commission and achieved approval for the New Island Plan and the North of Town Masterplan.

In this role he successfully negotiated UK and EU support for Jersey's Zero-Ten tax regime.

In June 2011, after the approval by the States of Jersey of his Island Plan by a majority of 38 to 1 votes and the St Helier Masterplan by 37 votes to 1,he resigned as Minister for Planning and Environment to concentrate on his UK and International responsibilities.

In the contest for four vacancies, Cohen was unsuccessful finishing sixth out of 13 candidates with 7,922 votes his election campaign having been overshadowed by media criticism of the Portelet development, a redevelopment initially approved in 2005 before Cohen's tenure as Planning Minister.