SUDBURY, Ont. -- A Liberal government would invest millions of dollars to support a clean technology initiative to create jobs and wealth, Justin Trudeau said today.

On a campaign swing through northern Ontario, Trudeau used a stop at a Laurentian University research institute to underscore a commitment to sustainable growth.

He said a Liberal government would invest $200 million a year to develop clean technologies in forestry, fisheries, mining, energy and farming.

This will not only boost economic growth, he said, but will also meet environmental challenges.

"The environment and the economy go together like paddles and canoes," he said. "You just can't get to where you're going unless you have both of them together."

Trudeau brought the same message later in the day to Sault Ste. Marie, Ont., which he said is the "alternative energy capital of North America."

There the Liberal leader addressed controversial tweets a Calgary candidate wrote as a teenager several years ago. Ala Buzreba has apologized for the tweets and Trudeau said he's glad she owned up to her mistakes.

Trudeau said it's time to bring together the private sector, provincial and territorial governments and research institutions to invest in sustainable growth.

In addition to the $200 million, there would be extra funding to help firms market their clean-technology products, he added.

"We'll invest $100 million more per year in organizations that have been successful at supporting the emergence of clean technology firms in Canada, including Sustainable Development Technology Canada," he said in Sudbury

The proposal would provide good jobs, create wealth and reduce pollution, he said.

He said Stephen Harper and the Conservatives have failed to deliver solid, sensible economic policies over the last decade and it's time for a change.

"We know the world has changed in the last 10 years," he said. "Mr. Harper and his government have not. Their plan has failed and they have no new ideas. We have to act now."