)[8][9] Eliasch began his career in turning around companies in 1985, when he joined the London-based private equity firm Tufton Group.

[15] He was an advisory board member of the Shimon Peres Peace Centre, World Peace Foundation, the Centre for Social Justice, Societe du Louvre and the British Olympic Association, a member of the Mayor of London's (Boris Johnson), Jerusalem's and Rome's International Business Advisory Councils.

[22] In 2006, he co-founded Cool Earth, a charity he co-chairs, which sponsors local NGOs to conserve endangered rainforest and has over 120,000 registered members.

[25][26] The Eliasch Review has served as a guideline for REDD (Reduced Emissions from Deforestation and Degradation) as part of the international climate change convention.

[27] In June 2008, the Brazilian Institute of Environment and Renewable Natural Resources began an investigation into a company acquired by Eliasch for alleged illegal deforestation prior to his ownership.

[31][32] Eliasch is currently a director of the Foundation for Renewable Energy and Environment, a non-profit, international organisation,[33] an advisory board member for the All-Party Parliamentary Group for the Polar Regions, and Brasilinvest.

[36] He chaired the 2021–22 HM Treasury net zero review technology and innovation advisory group,[16][37] RUSI's Food, Energy and Water security program, and was a member of the DEFRA Council for Sustainable Business.

[41] Eliasch met Prince Andrew, Duke of York in the 1990s and organised a charity tennis match at Buckingham Palace between John McEnroe and Björn Borg.

[43][44] In 2006, Eliasch co-founded the Global Strategy Forum with the late Rt Hon Michael Ancram, the Marquess of Lothian,[45] and became the foundation's first president.