Prime Minister Justin Trudeau has tapped a long-time Canadian diplomat to step into a revamped role of Canada's ambassador for climate change.

Canada hasn't had such an ambassador since January 2015.

Jennifer MacIntyre fills the role as of Tuesday, with a mandate to push Canada's international relationships on the climate change file, including promoting Canadian clean technology businesses abroad.

She is the fifth person to hold the title of ambassador for climate change — but the first where the role is not the equivalent of Canada's chief negotiator for climate change treaties.

As such, she will not be on hand next week when Trudeau sits down with other G20 leaders in Germany where the Paris climate change agreement will be front and centre.

Instead her role is to find ways for Canada to take advantage of any international opportunities for trade and investment that climate change policies bring.

MacIntyre was appointed ambassador to Switzerland and Liechtenstein in 2013, before returning to Canada earlier this year to work at Environment and Climate Change Canada.