Born and raised in Hamilton, Ontario, she is the eldest of four children of Dr. John McKenna, an Irish dentist and his Quebec-born wife Pat McKenna, who still live in the southwest part of Hamilton. On August 14, 1999, McKenna married entrepreneur and writer Scott Gilmore, with whom she has lived since 2002 in The Glebe, Ottawa. They have two daughters and one son.
McKenna was appointed Minister of Environment and Climate Change in Justin Trudeau’s first cabinet on November 4, 2015. One of her first appearances as Minister of Environment and Climate Change was at the 2015 United Nations Climate Change Conference in Paris.
In December 2016, McKenna led a clean-technology sector business delegation with Canadian and Chinese companies in China. Additionally, she served as the international executive vice-chair of the China Council for International Cooperation on Environment and Development and co-chaired the council’s annual general meeting with China’s Minister of Environmental Protection, Minister Chen Jining.
Some of McKenna’s critics have derisively nicknamed her “Climate Barbie”, a label McKenna considers a sexist insult Conservative MP Gerry Ritz caused controversy in September 2017 when he tweeted a link to a news story stating no industrialized nations were on pace to meet Paris Agreement carbon emission targets with the comment “Has anyone told our climate Barbie! [sic]” (referring to McKenna). Ritz deleted the original post within 20 minutes, afterward posted another message stating: “I apologize for the use of Barbie, it is not reflective of the role the Minister plays”. Conservative leader Andrew Scheer condemned Ritz’s comment later in the day and stated he would reach out to McKenna personally to “assure the minister that this type of behavior has no place in the Conservative caucus”.
In November 2018, in response to Ontario provincial government 2018 decision to cancel all climate action projects supported through the federal Low Carbon Economy Fund, McKenna announced that the Government of Canada would work directly with businesses to re-invest the $420-million remaining in the province’s Low Carbon Economy Fund.