Liese is a substitute for the Committee on Industry, Research and Energy, a member of the Delegation for relations with the countries of Central America and a substitute for the Delegation to the EU-Mexico Joint Parliamentary Committee. He was part of the Parliament's delegations to the 2008 United Nations Climate Change Conference in Poznań, to the 2013 United Nations Climate Change Conference in Warsaw and to the 2016 United Nations Climate Change Conference in Marrakesh.