Julie was appointed Minister for Climate Change on 13 May 2021, and Cabinet Secretary for Housing, Local Government and Planning on 21 March 2024.
Penodwyd hi yn Weinidog Newid Hinsawdd ar 13 Mai 2021, ac yn Ysgrifennydd y Cabinet dros Lywodraeth Leol, Tai a Chynllunio ar 21 Mawrth 2024.